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src/third-party/libpng/CHANGES (view raw)

   1#if 0
   2CHANGES - changes for libpng
   3
   4version 0.1 [March 29, 1995]
   5  initial work-in-progress release
   6
   7version 0.2 [April 1, 1995]
   8  added reader into png.h
   9  fixed small problems in stub file
  10
  11version 0.3 [April 8, 1995]
  12  added pull reader
  13  split up pngwrite.c to several files
  14  added pnglib.txt
  15  added example.c
  16  cleaned up writer, adding a few new transformations
  17  fixed some bugs in writer
  18  interfaced with zlib 0.5
  19  added K&R support
  20  added check for 64 KB blocks for 16 bit machines
  21
  22version 0.4 [April 26, 1995]
  23  cleaned up code and commented code
  24  simplified time handling into png_time
  25  created png_color_16 and png_color_8 to handle color needs
  26  cleaned up color type defines
  27  fixed various bugs
  28  made various names more consistent
  29  interfaced with zlib 0.71
  30  cleaned up zTXt reader and writer (using zlib's Reset functions)
  31  split transformations into pngrtran.c and pngwtran.c
  32
  33version 0.5 [April 30, 1995]
  34  interfaced with zlib 0.8
  35  fixed many reading and writing bugs
  36  saved using 3 spaces instead of tabs
  37
  38version 0.6 [May 1, 1995]
  39  first beta release
  40  added png_large_malloc() and png_large_free()
  41  added png_size_t
  42  cleaned up some compiler warnings
  43  added png_start_read_image()
  44
  45version 0.7 [June 24, 1995]
  46  cleaned up lots of bugs
  47  finished dithering and other stuff
  48  added test program
  49  changed name from pnglib to libpng
  50
  51version 0.71 [June 26, 1995]
  52  changed pngtest.png for zlib 0.93
  53  fixed error in libpng.txt and example.c
  54
  55version 0.8 [August 20, 1995]
  56  cleaned up some bugs
  57  added png_set_filler()
  58  split up pngstub.c into pngmem.c, pngio.c, and pngerror.c
  59  added #define's to remove unwanted code
  60  moved png_info_init() to png.c
  61  added old_size into png_realloc()
  62  added functions to manually set filtering and compression info
  63  changed compression parameters based on image type
  64  optimized filter selection code
  65  added version info
  66  changed external functions passing floats to doubles (k&r problems?)
  67  put all the configurable stuff in pngconf.h
  68  enabled png_set_shift to work with paletted images on read
  69  added png_read_update_info() - updates info structure with transformations
  70
  71Version 0.81 [August, 1995]
  72  incorporated Tim Wegner's medium model code (thanks, Tim)
  73
  74Version 0.82 [September, 1995]
  75  [unspecified changes]
  76
  77Version 0.85 [December, 1995]
  78  added more medium model code (almost everything's a far)
  79  added i/o, error, and memory callback functions
  80  fixed some bugs (16-bit, 4-bit interlaced, etc.)
  81  added first run progressive reader (barely tested)
  82
  83Version 0.86 [January, 1996]
  84  fixed bugs
  85  improved documentation
  86
  87Version 0.87 [January, 1996]
  88  fixed medium model bugs
  89  fixed other bugs introduced in 0.85 and 0.86
  90  added some minor documentation
  91
  92Version 0.88 [January, 1996]
  93  fixed progressive bugs
  94  replaced tabs with spaces
  95  cleaned up documentation
  96  added callbacks for read/write and warning/error functions
  97
  98Version 0.89 [June 5, 1996]
  99  Added new initialization API to make libpng work better with shared libs
 100    we now have png_create_read_struct(), png_create_write_struct(),
 101    png_create_info_struct(), png_destroy_read_struct(), and
 102    png_destroy_write_struct() instead of the separate calls to
 103    malloc and png_read_init(), png_info_init(), and png_write_init()
 104  Changed warning/error callback functions to fix bug - this means you
 105    should use the new initialization API if you were using the old
 106    png_set_message_fn() calls, and that the old API no longer exists
 107    so that people are aware that they need to change their code
 108  Changed filter selection API to allow selection of multiple filters
 109    since it didn't work in previous versions of libpng anyways
 110  Optimized filter selection code
 111  Fixed png_set_background() to allow using an arbitrary RGB color for
 112    paletted images
 113  Fixed gamma and background correction for paletted images, so
 114    png_correct_palette is not needed unless you are correcting an
 115    external palette (you will need to #define PNG_CORRECT_PALETTE_SUPPORTED
 116    in pngconf.h) - if nobody uses this, it may disappear in the future.
 117  Fixed bug with Borland 64K memory allocation (Alexander Lehmann)
 118  Fixed bug in interlace handling (Smarasderagd, I think)
 119  Added more error checking for writing and image to reduce invalid files
 120  Separated read and write functions so that they won't both be linked
 121    into a binary when only reading or writing functionality is used
 122  New pngtest image also has interlacing and zTXt
 123  Updated documentation to reflect new API
 124
 125Version 0.89c [June 17, 1996]
 126  Bug fixes.
 127
 128Version 0.90 [January, 1997]
 129  Made CRC errors/warnings on critical and ancillary chunks configurable
 130  libpng will use the zlib CRC routines by (compile-time) default
 131  Changed DOS small/medium model memory support - needs zlib 1.04 (Tim Wegner)
 132  Added external C++ wrapper statements to png.h (Gilles Dauphin)
 133  Allow PNG file to be read when some or all of file signature has already
 134    been read from the beginning of the stream.  ****This affects the size
 135    of info_struct and invalidates all programs that use a shared libpng****
 136  Fixed png_filler() declarations
 137  Fixed? background color conversions
 138  Fixed order of error function pointers to match documentation
 139  Current chunk name is now available in png_struct to reduce the number
 140    of nearly identical error messages (will simplify multi-lingual
 141    support when available)
 142  Try to get ready for unknown-chunk callback functions:
 143    - previously read critical chunks are flagged, so the chunk handling
 144      routines can determine if the chunk is in the right place
 145    - all chunk handling routines have the same prototypes, so we will
 146      be able to handle all chunks via a callback mechanism
 147  Try to fix Linux "setjmp" buffer size problems
 148  Removed png_large_malloc, png_large_free, and png_realloc functions.
 149
 150Version 0.95 [March, 1997]
 151  Fixed bug in pngwutil.c allocating "up_row" twice and "avg_row" never
 152  Fixed bug in PNG file signature compares when start != 0
 153  Changed parameter type of png_set_filler(...filler...) from png_byte
 154    to png_uint_32
 155  Added test for MACOS to ensure that both math.h and fp.h are not #included
 156  Added macros for libpng to be compiled as a Windows DLL (Andreas Kupries)
 157  Added "packswap" transformation, which changes the endianness of
 158    packed-pixel bytes (Kevin Bracey)
 159  Added "strip_alpha" transformation, which removes the alpha channel of
 160    input images without using it (not necessarily a good idea)
 161  Added "swap_alpha" transformation, which puts the alpha channel in front
 162    of the color bytes instead of after
 163  Removed all implicit variable tests which assume NULL == 0 (I think)
 164  Changed several variables to "png_size_t" to show 16/32-bit limitations
 165  Added new pCAL chunk read/write support
 166  Added experimental filter selection weighting (Greg Roelofs)
 167  Removed old png_set_rgbx() and png_set_xrgb() functions that have been
 168    obsolete for about 2 years now (use png_set_filler() instead)
 169  Added macros to read 16- and 32-bit ints directly from buffer, to be
 170    used only on those systems that support it (namely PowerPC and 680x0)
 171    With some testing, this may become the default for MACOS/PPC systems.
 172  Only calculate CRC on data if we are going to use it
 173  Added macros for zTXt compression type PNG_zTXt_COMPRESSION_???
 174  Added macros for simple libpng debugging output selectable at compile time
 175  Removed PNG_READ_END_MODE in progressive reader (Smarasderagd)
 176  More description of info_struct in libpng.txt and png.h
 177  More instructions in example.c
 178  More chunk types tested in pngtest.c
 179  Renamed pngrcb.c to pngset.c, and all png_read_<chunk> functions to be
 180    png_set_<chunk>.  We now have corresponding png_get_<chunk>
 181    functions in pngget.c to get information in info_ptr.  This isolates
 182    the application from the internal organization of png_info_struct
 183    (good for shared library implementations).
 184
 185Version 0.96 [May, 1997]
 186  Fixed serious bug with < 8bpp images introduced in 0.95
 187  Fixed 256-color transparency bug (Greg Roelofs)
 188  Fixed up documentation (Greg Roelofs, Laszlo Nyul)
 189  Fixed "error" in pngconf.h for Linux setjmp() behavior
 190  Fixed DOS medium model support (Tim Wegner)
 191  Fixed png_check_keyword() for case with error in static string text
 192  Added read of CRC after IEND chunk for embedded PNGs (Laszlo Nyul)
 193  Added typecasts to quiet compiler errors
 194  Added more debugging info
 195
 196Version 0.97 [January, 1998]
 197  Removed PNG_USE_OWN_CRC capability
 198  Relocated png_set_crc_action from pngrutil.c to pngrtran.c
 199  Fixed typecasts of "new_key", etc. (Andreas Dilger)
 200  Added RFC 1152 [sic] date support
 201  Fixed bug in gamma handling of 4-bit grayscale
 202  Added 2-bit grayscale gamma handling (Glenn R-P)
 203  Added more typecasts. 65536L becomes (png_uint_32)65536L, etc. (Glenn R-P)
 204  Minor corrections in libpng.txt
 205  Added simple sRGB support (Glenn R-P)
 206  Easier conditional compiling, e.g.,
 207    define PNG_READ/WRITE_NOT_FULLY_SUPPORTED;
 208    all configurable options can be selected from command-line instead
 209    of having to edit pngconf.h (Glenn R-P)
 210  Fixed memory leak in pngwrite.c (free info_ptr->text) (Glenn R-P)
 211  Added more conditions for png_do_background, to avoid changing
 212    black pixels to background when a background is supplied and
 213    no pixels are transparent
 214  Repaired PNG_NO_STDIO behavior
 215  Tested NODIV support and made it default behavior (Greg Roelofs)
 216  Added "-m" option and PNGTEST_DEBUG_MEMORY to pngtest (John Bowler)
 217  Regularized version numbering scheme and bumped shared-library major
 218    version number to 2 to avoid problems with libpng 0.89 apps
 219    (Greg Roelofs)
 220
 221Version 0.98 [January, 1998]
 222  Cleaned up some typos in libpng.txt and in code documentation
 223  Fixed memory leaks in pCAL chunk processing (Glenn R-P and John Bowler)
 224  Cosmetic change "display_gamma" to "screen_gamma" in pngrtran.c
 225  Changed recommendation about file_gamma for PC images to .51 from .45,
 226    in example.c and libpng.txt, added comments to distinguish between
 227    screen_gamma, viewing_gamma, and display_gamma.
 228  Changed all references to RFC1152 to read RFC1123 and changed the
 229    PNG_TIME_RFC1152_SUPPORTED macro to PNG_TIME_RFC1123_SUPPORTED
 230  Added png_invert_alpha capability (Glenn R-P -- suggestion by Jon Vincent)
 231  Changed srgb_intent from png_byte to int to avoid compiler bugs
 232
 233Version 0.99 [January 30, 1998]
 234  Free info_ptr->text instead of end_info_ptr->text in pngread.c (John Bowler)
 235  Fixed a longstanding "packswap" bug in pngtrans.c
 236  Fixed some inconsistencies in pngconf.h that prevented compiling with
 237    PNG_READ_GAMMA_SUPPORTED and PNG_READ_hIST_SUPPORTED undefined
 238  Fixed some typos and made other minor rearrangement of libpng.txt (Andreas)
 239  Changed recommendation about file_gamma for PC images to .50 from .51 in
 240    example.c and libpng.txt, and changed file_gamma for sRGB images to .45
 241  Added a number of functions to access information from the png structure
 242    png_get_image_height(), etc. (Glenn R-P, suggestion by Brad Pettit)
 243  Added TARGET_MACOS similar to zlib-1.0.8
 244  Define PNG_ALWAYS_EXTERN when __MWERKS__ && WIN32 are defined
 245  Added type casting to all png_malloc() function calls
 246
 247Version 0.99a [January 31, 1998]
 248  Added type casts and parentheses to all returns that return a value.(Tim W.)
 249
 250Version 0.99b [February 4, 1998]
 251  Added type cast png_uint_32 on malloc function calls where needed.
 252  Changed type of num_hist from png_uint_32 to int (same as num_palette).
 253  Added checks for rowbytes overflow, in case png_size_t is less than 32 bits.
 254  Renamed makefile.elf to makefile.lnx.
 255
 256Version 0.99c [February 7, 1998]
 257  More type casting.  Removed erroneous overflow test in pngmem.c.
 258  Added png_buffered_memcpy() and png_buffered_memset(), apply them to rowbytes.
 259  Added UNIX manual pages libpng.3 (incorporating libpng.txt) and  png.5.
 260
 261Version 0.99d [February 11, 1998]
 262  Renamed "far_to_near()" "png_far_to_near()"
 263  Revised libpng.3
 264  Version 99c "buffered" operations didn't work as intended.  Replaced them
 265    with png_memcpy_check() and png_memset_check().
 266  Added many "if (png_ptr == NULL) return" to quell compiler warnings about
 267    unused png_ptr, mostly in pngget.c and pngset.c.
 268  Check for overlength tRNS chunk present when indexed-color PLTE is read.
 269  Cleaned up spelling errors in libpng.3/libpng.txt
 270  Corrected a problem with png_get_tRNS() which returned undefined trans array
 271
 272Version 0.99e [February 28, 1998]
 273  Corrected png_get_tRNS() again.
 274  Add parentheses for easier reading of pngget.c, fixed "||" should be "&&".
 275  Touched up example.c to make more of it compileable, although the entire
 276    file still can't be compiled (Willem van Schaik)
 277  Fixed a bug in png_do_shift() (Bryan Tsai)
 278  Added a space in png.h prototype for png_write_chunk_start()
 279  Replaced pngtest.png with one created with zlib 1.1.1
 280  Changed pngtest to report PASS even when file size is different (Jean-loup G.)
 281  Corrected some logic errors in png_do_invert_alpha() (Chris Patterson)
 282
 283Version 0.99f [March 5, 1998]
 284  Corrected a bug in pngpread() introduced in version 99c (Kevin Bracey)
 285  Moved makefiles into a "scripts" directory, and added INSTALL instruction file
 286  Added makefile.os2 and pngos2.def (A. Zabolotny) and makefile.s2x (W. Sebok)
 287  Added pointers to "note on libpng versions" in makefile.lnx and README
 288  Added row callback feature when reading and writing nonprogressive rows
 289    and added a test of this feature in pngtest.c
 290  Added user transform callbacks, with test of the feature in pngtest.c
 291
 292Version 0.99g [March 6, 1998, morning]
 293  Minor changes to pngtest.c to suppress compiler warnings.
 294  Removed "beta" language from documentation.
 295
 296Version 0.99h [March 6, 1998, evening]
 297  Minor changes to previous minor changes to pngtest.c
 298  Changed PNG_READ_NOT_FULLY_SUPPORTED to PNG_READ_TRANSFORMS_NOT_SUPPORTED
 299    and added PNG_PROGRESSIVE_READ_NOT_SUPPORTED macro
 300  Added user transform capability
 301
 302Version 1.00 [March 7, 1998]
 303  Changed several typedefs in pngrutil.c
 304  Added makefile.wat (Pawel Mrochen), updated makefile.tc3 (Willem van Schaik)
 305  Replaced "while(1)" with "for(;;)"
 306  Added PNGARG() to prototypes in pngtest.c and removed some prototypes
 307  Updated some of the makefiles (Tom Lane)
 308  Changed some typedefs (s_start, etc.) in pngrutil.c
 309  Fixed dimensions of "short_months" array in pngwrite.c
 310  Replaced ansi2knr.c with the one from jpeg-v6
 311
 312Version 1.0.0 [March 8, 1998]
 313  Changed name from 1.00 to 1.0.0 (Adam Costello)
 314  Added smakefile.ppc (with SCOPTIONS.ppc) for Amiga PPC (Andreas Kleinert)
 315
 316Version 1.0.0a [March 9, 1998]
 317  Fixed three bugs in pngrtran.c to make gamma+background handling consistent
 318    (Greg Roelofs)
 319  Changed format of the PNG_LIBPNG_VER integer to xyyzz instead of xyz
 320    for major, minor, and bugfix releases.  This is 10001. (Adam Costello,
 321    Tom Lane)
 322  Make months range from 1-12 in png_convert_to_rfc1123
 323
 324Version 1.0.0b [March 13, 1998]
 325  Quieted compiler complaints about two empty "for" loops in pngrutil.c
 326  Minor changes to makefile.s2x
 327  Removed #ifdef/#endif around a png_free() in pngread.c
 328
 329Version 1.0.1 [March 14, 1998]
 330  Changed makefile.s2x to reduce security risk of using a relative pathname
 331  Fixed some typos in the documentation (Greg).
 332  Fixed a problem with value of "channels" returned by png_read_update_info()
 333
 334Version 1.0.1a [April 21, 1998]
 335  Optimized Paeth calculations by replacing abs() function calls with intrinsics
 336  plus other loop optimizations. Improves avg decoding speed by about 20%.
 337  Commented out i386istic "align" compiler flags in makefile.lnx.
 338  Reduced the default warning level in some makefiles, to make them consistent.
 339  Removed references to IJG and JPEG in the ansi2knr.c copyright statement.
 340  Fixed a bug in png_do_strip_filler with XXRRGGBB => RRGGBB transformation.
 341  Added grayscale and 16-bit capability to png_do_read_filler().
 342  Fixed a bug in pngset.c, introduced in version 0.99c, that sets rowbytes
 343    too large when writing an image with bit_depth < 8 (Bob Dellaca).
 344  Corrected some bugs in the experimental weighted filtering heuristics.
 345  Moved a misplaced pngrutil code block that truncates tRNS if it has more
 346    than num_palette entries -- test was done before num_palette was defined.
 347  Fixed a png_convert_to_rfc1123() bug that converts day 31 to 0 (Steve Eddins).
 348  Changed compiler flags in makefile.wat for better optimization
 349    (Pawel Mrochen).
 350
 351Version 1.0.1b [May 2, 1998]
 352  Relocated png_do_gray_to_rgb() within png_do_read_transformations() (Greg).
 353  Relocated the png_composite macros from pngrtran.c to png.h (Greg).
 354  Added makefile.sco (contributed by Mike Hopkirk).
 355  Fixed two bugs (missing definitions of "istop") introduced in libpng-1.0.1a.
 356  Fixed a bug in pngrtran.c that would set channels=5 under some circumstances.
 357  More work on the Paeth-filtering, achieving imperceptible speedup
 358    (A Kleinert).
 359  More work on loop optimization which may help when compiled with C++
 360    compilers.
 361  Added warnings when people try to use transforms they've defined out.
 362  Collapsed 4 "i" and "c" loops into single "i" loops in pngrtran and pngwtran.
 363  Revised paragraph about png_set_expand() in libpng.txt and libpng.3 (Greg)
 364
 365Version 1.0.1c [May 11, 1998]
 366  Fixed a bug in pngrtran.c (introduced in libpng-1.0.1a) where the masks for
 367    filler bytes should have been 0xff instead of 0xf.
 368  Added max_pixel_depth=32 in pngrutil.c when using FILLER with palette images.
 369  Moved PNG_WRITE_WEIGHTED_FILTER_SUPPORTED and PNG_WRITE_FLUSH_SUPPORTED
 370    out of the PNG_WRITE_TRANSFORMS_NOT_SUPPORTED block of pngconf.h
 371  Added "PNG_NO_WRITE_TRANSFORMS" etc., as alternatives for *_NOT_SUPPORTED,
 372    for consistency, in pngconf.h
 373  Added individual "ifndef PNG_NO_[CAPABILITY]" in pngconf.h to make it easier
 374    to remove unwanted capabilities via the compile line
 375  Made some corrections to grammar (which, it's) in documentation (Greg).
 376  Corrected example.c, use of row_pointers in png_write_image().
 377
 378Version 1.0.1d [May 24, 1998]
 379  Corrected several statements that used side effects illegally in pngrutil.c
 380    and pngtrans.c, that were introduced in version 1.0.1b
 381  Revised png_read_rows() to avoid repeated if-testing for NULL (A Kleinert)
 382  More corrections to example.c, use of row_pointers in png_write_image()
 383    and png_read_rows().
 384  Added pngdll.mak and pngdef.pas to scripts directory, contributed by
 385    Bob Dellaca, to make a png32bd.dll with Borland C++ 4.5
 386  Fixed error in example.c with png_set_text: num_text is 3, not 2 (Guido V.)
 387  Changed several loops from count-down to count-up, for consistency.
 388
 389Version 1.0.1e [June 6, 1998]
 390  Revised libpng.txt and libpng.3 description of png_set_read|write_fn(), and
 391    added warnings when people try to set png_read_fn and png_write_fn in
 392    the same structure.
 393  Added a test such that png_do_gamma will be done when num_trans==0
 394    for truecolor images that have defined a background.  This corrects an
 395    error that was introduced in libpng-0.90 that can cause gamma processing
 396    to be skipped.
 397  Added tests in png.h to include "trans" and "trans_values" in structures
 398    when PNG_READ_BACKGROUND_SUPPORTED or PNG_READ_EXPAND_SUPPORTED is defined.
 399  Add png_free(png_ptr->time_buffer) in png_destroy_read_struct()
 400  Moved png_convert_to_rfc_1123() from pngwrite.c to png.c
 401  Added capability for user-provided malloc_fn() and free_fn() functions,
 402    and revised pngtest.c to demonstrate their use, replacing the
 403    PNGTEST_DEBUG_MEM feature.
 404  Added makefile.w32, for Microsoft C++ 4.0 and later (Tim Wegner).
 405
 406Version 1.0.2 [June 14, 1998]
 407  Fixed two bugs in makefile.bor .
 408
 409Version 1.0.2a [December 30, 1998]
 410  Replaced and extended code that was removed from png_set_filler() in 1.0.1a.
 411  Fixed a bug in png_do_filler() that made it fail to write filler bytes in
 412    the left-most pixel of each row (Kevin Bracey).
 413  Changed "static pngcharp tIME_string" to "static char tIME_string[30]"
 414    in pngtest.c (Duncan Simpson).
 415  Fixed a bug in pngtest.c that caused pngtest to try to write a tIME chunk
 416    even when no tIME chunk was present in the source file.
 417  Fixed a problem in pngrutil.c: gray_to_rgb didn't always work with 16-bit.
 418  Fixed a problem in png_read_push_finish_row(), which would not skip some
 419    passes that it should skip, for images that are less than 3 pixels high.
 420  Interchanged the order of calls to png_do_swap() and png_do_shift()
 421    in pngwtran.c (John Cromer).
 422  Added #ifdef PNG_DEBUG/#endif surrounding use of PNG_DEBUG in png.h .
 423  Changed "bad adaptive filter type" from error to warning in pngrutil.c .
 424  Fixed a documentation error about default filtering with 8-bit indexed-color.
 425  Separated the PNG_NO_STDIO macro into PNG_NO_STDIO and PNG_NO_CONSOLE_IO
 426    (L. Peter Deutsch).
 427  Added png_set_rgb_to_gray() and png_get_rgb_to_gray_status() functions.
 428  Added png_get_copyright() and png_get_header_version() functions.
 429  Revised comments on png_set_progressive_read_fn() in libpng.txt and example.c
 430  Added information about debugging in libpng.txt and libpng.3 .
 431  Changed "ln -sf" to "ln -s -f" in makefile.s2x, makefile.lnx, and
 432    makefile.sco.
 433  Removed lines after Dynamic Dependencies" in makefile.aco .
 434  Revised makefile.dec to make a shared library (Jeremie Petit).
 435  Removed trailing blanks from all files.
 436
 437Version 1.0.2a [January 6, 1999]
 438  Removed misplaced #endif and #ifdef PNG_NO_EXTERN near the end of png.h
 439  Added "if" tests to silence complaints about unused png_ptr in png.h and png.c
 440  Changed "check_if_png" function in example.c to return true (nonzero) if PNG.
 441  Changed libpng.txt to demonstrate png_sig_cmp() instead of png_check_sig()
 442    which is obsolete.
 443
 444Version 1.0.3 [January 14, 1999]
 445  Added makefile.hux, for Hewlett Packard HPUX 10.20 and 11.00 (Jim Rice)
 446  Added a statement of Y2K compliance in png.h, libpng.3, and Y2KINFO.
 447
 448Version 1.0.3a [August 12, 1999]
 449  Added check for PNG_READ_INTERLACE_SUPPORTED in pngread.c; issue a warning
 450    if an attempt is made to read an interlaced image when it's not supported.
 451  Added check if png_ptr->trans is defined before freeing it in pngread.c
 452  Modified the Y2K statement to include versions back to version 0.71
 453  Fixed a bug in the check for valid IHDR bit_depth/color_types in pngrutil.c
 454  Modified makefile.wat (added -zp8 flag, ".symbolic", changed some comments)
 455  Replaced leading blanks with tab characters in makefile.hux
 456  Changed "dworkin.wustl.edu" to "ccrc.wustl.edu" in various documents.
 457  Changed (float)red and (float)green to (double)red, (double)green
 458    in png_set_rgb_to_gray() to avoid "promotion" problems in AIX.
 459  Fixed a bug in pngconf.h that omitted <stdio.h> when PNG_DEBUG==0 (K Bracey).
 460  Reformatted libpng.3 and libpngpf.3 with proper fonts (script by J. vanZandt).
 461  Updated documentation to refer to the PNG-1.2 specification.
 462  Removed ansi2knr.c and left pointers to the latest source for ansi2knr.c
 463    in makefile.knr, INSTALL, and README (L. Peter Deutsch)
 464  Fixed bugs in calculation of the length of rowbytes when adding alpha
 465    channels to 16-bit images, in pngrtran.c (Chris Nokleberg)
 466  Added function png_set_user_transform_info() to store user_transform_ptr,
 467    user_depth, and user_channels into the png_struct, and a function
 468    png_get_user_transform_ptr() to retrieve the pointer (Chris Nokleberg)
 469  Added function png_set_empty_plte_permitted() to make libpng useable
 470    in MNG applications.
 471  Corrected the typedef for png_free_ptr in png.h (Jesse Jones).
 472  Correct gamma with srgb is 45455 instead of 45000 in pngrutil.c, to be
 473    consistent with PNG-1.2, and allow variance of 500 before complaining.
 474  Added assembler code contributed by Intel in file pngvcrd.c and modified
 475    makefile.w32 to use it (Nirav Chhatrapati, INTEL Corporation,
 476    Gilles Vollant)
 477  Changed "ln -s -f" to "ln -f -s" in the makefiles to make Solaris happy.
 478  Added some aliases for png_set_expand() in pngrtran.c, namely
 479    png_set_expand_PLTE(), png_set_expand_depth(), and png_set_expand_tRNS()
 480    (Greg Roelofs, in "PNG: The Definitive Guide").
 481  Added makefile.beo for BEOS on X86, contributed by Sander Stok.
 482
 483Version 1.0.3b [August 26, 1999]
 484  Replaced 2147483647L several places with PNG_MAX_UINT macro, defined in png.h
 485  Changed leading blanks to tabs in all makefiles.
 486  Define PNG_USE_PNGVCRD in makefile.w32, to get MMX assembler code.
 487  Made alternate versions of  png_set_expand() in pngrtran.c, namely
 488    png_set_gray_1_2_4_to_8, png_set_palette_to_rgb, and png_set_tRNS_to_alpha
 489    (Greg Roelofs, in "PNG: The Definitive Guide").  Deleted the 1.0.3a aliases.
 490  Relocated start of 'extern "C"' block in png.h so it doesn't include pngconf.h
 491  Revised calculation of num_blocks in pngmem.c to avoid a potentially
 492    negative shift distance, whose results are undefined in the C language.
 493  Added a check in pngset.c to prevent writing multiple tIME chunks.
 494  Added a check in pngwrite.c to detect invalid small window_bits sizes.
 495
 496Version 1.0.3d [September 4, 1999]
 497  Fixed type casting of igamma in pngrutil.c
 498  Added new png_expand functions to scripts/pngdef.pas and pngos2.def
 499  Added a demo read_user_transform_fn that examines the row filters in pngtest.c
 500
 501Version 1.0.4 [September 24, 1999, not distributed publicly]
 502  Define PNG_ALWAYS_EXTERN in pngconf.h if __STDC__ is defined
 503  Delete #define PNG_INTERNAL and include "png.h" from pngasmrd.h
 504  Made several minor corrections to pngtest.c
 505  Renamed the makefiles with longer but more user friendly extensions.
 506  Copied the PNG copyright and license to a separate LICENSE file.
 507  Revised documentation, png.h, and example.c to remove reference to
 508    "viewing_gamma" which no longer appears in the PNG specification.
 509  Revised pngvcrd.c to use MMX code for interlacing only on the final pass.
 510  Updated pngvcrd.c to use the faster C filter algorithms from libpng-1.0.1a
 511  Split makefile.win32vc into two versions, makefile.vcawin32 (uses MMX
 512    assembler code) and makefile.vcwin32 (doesn't).
 513  Added a CPU timing report to pngtest.c (enabled by defining PNGTEST_TIMING)
 514  Added a copy of pngnow.png to the distribution.
 515
 516Version 1.0.4a [September 25, 1999]
 517  Increase max_pixel_depth in pngrutil.c if a user transform needs it.
 518  Changed several division operations to right-shifts in pngvcrd.c
 519
 520Version 1.0.4b [September 30, 1999]
 521  Added parentheses in line 3732 of pngvcrd.c
 522  Added a comment in makefile.linux warning about buggy -O3 in pgcc 2.95.1
 523
 524Version 1.0.4c [October 1, 1999]
 525  Added a "png_check_version" function in png.c and pngtest.c that will generate
 526    a helpful compiler error if an old png.h is found in the search path.
 527  Changed type of png_user_transform_depth|channels from int to png_byte.
 528  Added "Libpng is OSI Certified Open Source Software" statement to png.h
 529
 530Version 1.0.4d [October 6, 1999]
 531  Changed 0.45 to 0.45455 in png_set_sRGB()
 532  Removed unused PLTE entries from pngnow.png
 533  Re-enabled some parts of pngvcrd.c (png_combine_row) that work properly.
 534
 535Version 1.0.4e [October 10, 1999]
 536  Fixed sign error in pngvcrd.c (Greg Roelofs)
 537  Replaced some instances of memcpy with simple assignments in pngvcrd (GR-P)
 538
 539Version 1.0.4f [October 15, 1999]
 540  Surrounded example.c code with #if 0 .. #endif to prevent people from
 541    inadvertently trying to compile it.
 542  Changed png_get_header_version() from a function to a macro in png.h
 543  Added type casting mostly in pngrtran.c and pngwtran.c
 544  Removed some pointless "ptr = NULL" in pngmem.c
 545  Added a "contrib" directory containing the source code from Greg's book.
 546
 547Version 1.0.5 [October 15, 1999]
 548  Minor editing of the INSTALL and README files.
 549
 550Version 1.0.5a [October 23, 1999]
 551  Added contrib/pngsuite and contrib/pngminus (Willem van Schaik)
 552  Fixed a typo in the png_set_sRGB() function call in example.c (Jan Nijtmans)
 553  Further optimization and bugfix of pngvcrd.c
 554  Revised pngset.c so that it does not allocate or free memory in the user's
 555    text_ptr structure.  Instead, it makes its own copy.
 556  Created separate write_end_info_struct in pngtest.c for a more severe test.
 557  Added code in pngwrite.c to free info_ptr->text[i].key to stop a memory leak.
 558
 559Version 1.0.5b [November 23, 1999]
 560  Moved PNG_FLAG_HAVE_CHUNK_HEADER, PNG_FLAG_BACKGROUND_IS_GRAY and
 561    PNG_FLAG_WROTE_tIME from flags to mode.
 562  Added png_write_info_before_PLTE() function.
 563  Fixed some typecasting in contrib/gregbook/*.c
 564  Updated scripts/makevms.com and added makevms.com to contrib/gregbook
 565    and contrib/pngminus (Martin Zinser)
 566
 567Version 1.0.5c [November 26, 1999]
 568  Moved png_get_header_version from png.h to png.c, to accommodate ansi2knr.
 569  Removed all global arrays (according to PNG_NO_GLOBAL_ARRAYS macro), to
 570    accommodate making DLL's: Moved usr_png_ver from global variable to function
 571    png_get_header_ver() in png.c.  Moved png_sig to png_sig_bytes in png.c and
 572    eliminated use of png_sig in pngwutil.c.  Moved the various png_CHNK arrays
 573    into pngtypes.h.  Eliminated use of global png_pass arrays.  Declared the
 574    png_CHNK and png_pass arrays to be "const".  Made the global arrays
 575    available to applications (although none are used in libpng itself) when
 576    PNG_NO_GLOBAL_ARRAYS is not defined or when PNG_GLOBAL_ARRAYS is defined.
 577  Removed some extraneous "-I" from contrib/pngminus/makefile.std
 578  Changed the PNG_sRGB_INTENT macros in png.h to be consistent with PNG-1.2.
 579  Change PNG_SRGB_INTENT to PNG_sRGB_INTENT in libpng.txt and libpng.3
 580
 581Version 1.0.5d [November 29, 1999]
 582  Add type cast (png_const_charp) two places in png.c
 583  Eliminated pngtypes.h; use macros instead to declare PNG_CHNK arrays.
 584  Renamed "PNG_GLOBAL_ARRAYS" to "PNG_USE_GLOBAL_ARRAYS" and made available
 585    to applications a macro "PNG_USE_LOCAL_ARRAYS".
 586  comment out (with #ifdef) all the new declarations when
 587    PNG_USE_GLOBAL_ARRAYS is defined.
 588  Added PNG_EXPORT_VAR macro to accommodate making DLL's.
 589
 590Version 1.0.5e [November 30, 1999]
 591  Added iCCP, iTXt, and sPLT support; added "lang" member to the png_text
 592    structure; refactored the inflate/deflate support to make adding new chunks
 593    with trailing compressed parts easier in the future, and added new functions
 594    png_free_iCCP, png_free_pCAL, png_free_sPLT, png_free_text, png_get_iCCP,
 595    png_get_spalettes, png_set_iCCP, png_set_spalettes (Eric S. Raymond).
 596    NOTE: Applications that write text chunks MUST define png_text->lang
 597    before calling png_set_text(). It must be set to NULL if you want to
 598    write tEXt or zTXt chunks.  If you want your application to be able to
 599    run with older versions of libpng, use
 600
 601      #ifdef PNG_iTXt_SUPPORTED
 602         png_text[i].lang = NULL;
 603      #endif
 604
 605  Changed png_get_oFFs() and png_set_oFFs() to use signed rather than unsigned
 606    offsets (Eric S. Raymond).
 607  Combined PNG_READ_cHNK_SUPPORTED and PNG_WRITE_cHNK_SUPPORTED macros into
 608    PNG_cHNK_SUPPORTED and combined the three types of PNG_text_SUPPORTED
 609    macros, leaving the separate macros also available.
 610  Removed comments on #endifs at the end of many short, non-nested #if-blocks.
 611
 612Version 1.0.5f [December 6, 1999]
 613  Changed makefile.solaris to issue a warning about potential problems when
 614    the ucb "ld" is in the path ahead of the ccs "ld".
 615  Removed "- [date]" from the "synopsis" line in libpng.3 and libpngpf.3.
 616  Added sCAL chunk support (Eric S. Raymond).
 617
 618Version 1.0.5g [December 7, 1999]
 619  Fixed "png_free_spallettes" typo in png.h
 620  Added code to handle new chunks in pngpread.c
 621  Moved PNG_CHNK string macro definitions outside of PNG_NO_EXTERN block
 622  Added "translated_key" to png_text structure and png_write_iTXt().
 623  Added code in pngwrite.c to work around a newly discovered zlib bug.
 624
 625Version 1.0.5h [December 10, 1999]
 626  NOTE: regarding the note for version 1.0.5e, the following must also
 627    be included in your code:
 628        png_text[i].translated_key = NULL;
 629  Unknown chunk handling is now supported.
 630  Option to eliminate all floating point support was added.  Some new
 631    fixed-point functions such as png_set_gAMA_fixed() were added.
 632  Expanded tabs and removed trailing blanks in source files.
 633
 634Version 1.0.5i [December 13, 1999]
 635  Added some type casts to silence compiler warnings.
 636  Renamed "png_free_spalette" to "png_free_spalettes" for consistency.
 637  Removed leading blanks from a #define in pngvcrd.c
 638  Added some parameters to the new png_set_keep_unknown_chunks() function.
 639  Added a test for up->location != 0 in the first instance of writing
 640    unknown chunks in pngwrite.c
 641  Changed "num" to "i" in png_free_spalettes() and png_free_unknowns() to
 642    prevent recursion.
 643  Added png_free_hIST() function.
 644  Various patches to fix bugs in the sCAL and integer cHRM processing,
 645    and to add some convenience macros for use with sCAL.
 646
 647Version 1.0.5j [December 21, 1999]
 648  Changed "unit" parameter of png_write_sCAL from png_byte to int, to work
 649    around buggy compilers.
 650  Added new type "png_fixed_point" for integers that hold float*100000 values
 651  Restored backward compatibility of tEXt/zTXt chunk processing:
 652    Restored the first four members of png_text to the same order as v.1.0.5d.
 653    Added members "lang_key" and "itxt_length" to png_text struct.  Set
 654    text_length=0 when "text" contains iTXt data.  Use the "compression"
 655    member to distinguish among tEXt/zTXt/iTXt types.  Added
 656    PNG_ITXT_COMPRESSION_NONE (1) and PNG_ITXT_COMPRESSION_zTXt(2) macros.
 657    The "Note" above, about backward incompatibility of libpng-1.0.5e, no
 658    longer applies.
 659  Fixed png_read|write_iTXt() to read|write parameters in the right order,
 660    and to write the iTXt chunk after IDAT if it appears in the end_ptr.
 661  Added pnggccrd.c, version of pngvcrd.c Intel assembler for gcc (Greg Roelofs)
 662  Reversed the order of trying to write floating-point and fixed-point gAMA.
 663
 664Version 1.0.5k [December 27, 1999]
 665  Added many parentheses, e.g., "if (a && b & c)" becomes "if (a && (b & c))"
 666  Added png_handle_as_unknown() function (Glenn)
 667  Added png_free_chunk_list() function and chunk_list and num_chunk_list members
 668    of png_ptr.
 669  Eliminated erroneous warnings about multiple sPLT chunks and sPLT-after-PLTE.
 670  Fixed a libpng-1.0.5h bug in pngrutil.c that was issuing erroneous warnings
 671    about ignoring incorrect gAMA with sRGB (gAMA was in fact not ignored)
 672  Added png_free_tRNS(); png_set_tRNS() now malloc's its own trans array (ESR).
 673  Define png_get_int_32 when oFFs chunk is supported as well as when pCAL is.
 674  Changed type of proflen from png_int_32 to png_uint_32 in png_get_iCCP().
 675
 676Version 1.0.5l [January 1, 2000]
 677  Added functions png_set_read_user_chunk_fn() and png_get_user_chunk_ptr()
 678    for setting a callback function to handle unknown chunks and for
 679    retrieving the associated user pointer (Glenn).
 680
 681Version 1.0.5m [January 7, 2000]
 682  Added high-level functions png_read_png(), png_write_png(), png_free_pixels().
 683
 684Version 1.0.5n [January 9, 2000]
 685  Added png_free_PLTE() function, and modified png_set_PLTE() to malloc its
 686    own memory for info_ptr->palette.  This makes it safe for the calling
 687    application to free its copy of the palette any time after it calls
 688    png_set_PLTE().
 689
 690Version 1.0.5o [January 20, 2000]
 691  Cosmetic changes only (removed some trailing blanks and TABs)
 692
 693Version 1.0.5p [January 31, 2000]
 694  Renamed pngdll.mak to makefile.bd32
 695  Cosmetic changes in pngtest.c
 696
 697Version 1.0.5q [February 5, 2000]
 698  Relocated the makefile.solaris warning about PATH problems.
 699  Fixed pngvcrd.c bug by pushing/popping registers in mmxsupport (Bruce Oberg)
 700  Revised makefile.gcmmx
 701  Added PNG_SETJMP_SUPPORTED, PNG_SETJMP_NOT_SUPPORTED, and PNG_ABORT() macros
 702
 703Version 1.0.5r [February 7, 2000]
 704  Removed superfluous prototype for png_get_itxt from png.h
 705  Fixed a bug in pngrtran.c that improperly expanded the background color.
 706  Return *num_text=0 from png_get_text() when appropriate, and fix documentation
 707    of png_get_text() in libpng.txt/libpng.3.
 708
 709Version 1.0.5s [February 18, 2000]
 710  Added "png_jmp_env()" macro to pngconf.h, to help people migrate to the
 711    new error handler that's planned for the next libpng release, and changed
 712    example.c, pngtest.c, and contrib programs to use this macro.
 713  Revised some of the DLL-export macros in pngconf.h (Greg Roelofs)
 714  Fixed a bug in png_read_png() that caused it to fail to expand some images
 715    that it should have expanded.
 716  Fixed some mistakes in the unused and undocumented INCH_CONVERSIONS functions
 717    in pngget.c
 718  Changed the allocation of palette, history, and trans arrays back to
 719    the version 1.0.5 method (linking instead of copying) which restores
 720    backward compatibility with version 1.0.5.  Added some remarks about
 721    that in example.c.  Added "free_me" member to info_ptr and png_ptr
 722    and added png_free_data() function.
 723  Updated makefile.linux and makefile.gccmmx to make directories conditionally.
 724  Made cosmetic changes to pngasmrd.h
 725  Added png_set_rows() and png_get_rows(), for use with png_read|write_png().
 726  Modified png_read_png() to allocate info_ptr->row_pointers only if it
 727    hasn't already been allocated.
 728
 729Version 1.0.5t [March 4, 2000]
 730  Changed png_jmp_env() migration aiding macro to png_jmpbuf().
 731  Fixed "interlace" typo (should be "interlaced") in contrib/gregbook/read2-x.c
 732  Fixed bug with use of PNG_BEFORE_IHDR bit in png_ptr->mode, introduced when
 733    PNG_FLAG_HAVE_CHUNK_HEADER was moved into png_ptr->mode in version 1.0.5b
 734  Files in contrib/gregbook were revised to use png_jmpbuf() and to select
 735    a 24-bit visual if one is available, and to allow abbreviated options.
 736  Files in contrib/pngminus were revised to use the png_jmpbuf() macro.
 737  Removed spaces in makefile.linux and makefile.gcmmx, introduced in 1.0.5s
 738
 739Version 1.0.5u [March 5, 2000]
 740  Simplified the code that detects old png.h in png.c and pngtest.c
 741  Renamed png_spalette (_p, _pp) to png_sPLT_t (_tp, _tpp)
 742  Increased precision of rgb_to_gray calculations from 8 to 15 bits and
 743    added png_set_rgb_to_gray_fixed() function.
 744  Added makefile.bc32 (32-bit Borland C++, C mode)
 745
 746Version 1.0.5v [March 11, 2000]
 747  Added some parentheses to the png_jmpbuf macro definition.
 748  Updated references to the zlib home page, which has moved to freesoftware.com.
 749  Corrected bugs in documentation regarding png_read_row() and png_write_row().
 750  Updated documentation of png_rgb_to_gray calculations in libpng.3/libpng.txt.
 751  Renamed makefile.borland,turboc3 back to makefile.bor,tc3 as in version 1.0.3,
 752    revised borland makefiles; added makefile.ibmvac3 and makefile.gcc (Cosmin)
 753
 754Version 1.0.6 [March 20, 2000]
 755  Minor revisions of makefile.bor, libpng.txt, and gregbook/rpng2-win.c
 756  Added makefile.sggcc (SGI IRIX with gcc)
 757
 758Version 1.0.6d [April 7, 2000]
 759  Changed sprintf() to strcpy() in png_write_sCAL_s() to work without STDIO
 760  Added data_length parameter to png_decompress_chunk() function
 761  Revised documentation to remove reference to abandoned png_free_chnk functions
 762  Fixed an error in png_rgb_to_gray_fixed()
 763  Revised example.c, usage of png_destroy_write_struct().
 764  Renamed makefile.ibmvac3 to makefile.ibmc, added libpng.icc IBM project file
 765  Added a check for info_ptr->free_me&PNG_FREE_TEXT when freeing text in png.c
 766  Simplify png_sig_bytes() function to remove use of non-ISO-C strdup().
 767
 768Version 1.0.6e [April 9, 2000]
 769  Added png_data_freer() function.
 770  In the code that checks for over-length tRNS chunks, added check of
 771    info_ptr->num_trans as well as png_ptr->num_trans (Matthias Benckmann)
 772  Minor revisions of libpng.txt/libpng.3.
 773  Check for existing data and free it if the free_me flag is set, in png_set_*()
 774    and png_handle_*().
 775  Only define PNG_WEIGHTED_FILTERS_SUPPORTED when PNG_FLOATING_POINT_SUPPORTED
 776    is defined.
 777  Changed several instances of PNG_NO_CONSOLE_ID to PNG_NO_STDIO in pngrutil.c
 778    and mentioned the purposes of the two macros in libpng.txt/libpng.3.
 779
 780Version 1.0.6f [April 14, 2000]
 781  Revised png_set_iCCP() and png_set_rows() to avoid prematurely freeing data.
 782  Add checks in png_set_text() for NULL members of the input text structure.
 783  Revised libpng.txt/libpng.3.
 784  Removed superfluous prototype for png_set_iTXt from png.h
 785  Removed "else" from pngread.c, after png_error(), and changed "0" to "length".
 786  Changed several png_errors about malformed ancillary chunks to png_warnings.
 787
 788Version 1.0.6g [April 24, 2000]
 789  Added png_pass-* arrays to pnggccrd.c when PNG_USE_LOCAL_ARRAYS is defined.
 790  Relocated paragraph about png_set_background() in libpng.3/libpng.txt
 791    and other revisions (Matthias Benckmann)
 792  Relocated info_ptr->free_me, png_ptr->free_me, and other info_ptr and
 793    png_ptr members to restore binary compatibility with libpng-1.0.5
 794    (breaks compatibility with libpng-1.0.6).
 795
 796Version 1.0.6h [April 24, 2000]
 797  Changed shared library so-number pattern from 2.x.y.z to xy.z (this builds
 798    libpng.so.10 & libpng.so.10.6h instead of libpng.so.2 & libpng.so.2.1.0.6h)
 799    This is a temporary change for test purposes.
 800
 801Version 1.0.6i [May 2, 2000]
 802  Rearranged some members at the end of png_info and png_struct, to put
 803    unknown_chunks_num and free_me within the original size of the png_structs
 804    and free_me, png_read_user_fn, and png_free_fn within the original png_info,
 805    because some old applications allocate the structs directly instead of
 806    using png_create_*().
 807  Added documentation of user memory functions in libpng.txt/libpng.3
 808  Modified png_read_png so that it will use user_allocated row_pointers
 809    if present, unless free_me directs that it be freed, and added description
 810    of the use of png_set_rows() and png_get_rows() in libpng.txt/libpng.3.
 811  Added PNG_LEGACY_SUPPORTED macro, and #ifdef out all new (since version
 812    1.00) members of png_struct and png_info, to regain binary compatibility
 813    when you define this macro.  Capabilities lost in this event
 814    are user transforms (new in version 1.0.0),the user transform pointer
 815    (new in version 1.0.2), rgb_to_gray (new in 1.0.5), iCCP, sCAL, sPLT,
 816    the high-level interface, and unknown chunks support (all new in 1.0.6).
 817    This was necessary because of old applications that allocate the structs
 818    directly as authors were instructed to do in libpng-0.88 and earlier,
 819    instead of using png_create_*().
 820  Added modes PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT which
 821    can be used to detect codes that directly allocate the structs, and
 822    code to check these modes in png_read_init() and png_write_init() and
 823    generate a libpng error if the modes aren't set and PNG_LEGACY_SUPPORTED
 824    was not defined.
 825  Added makefile.intel and updated makefile.watcom (Pawel Mrochen)
 826
 827Version 1.0.6j [May 3, 2000]
 828  Overloaded png_read_init() and png_write_init() with macros that convert
 829    calls to png_read_init_2() or png_write_init_2() that check the version
 830    and structure sizes.
 831
 832Version 1.0.7beta11 [May 7, 2000]
 833  Removed the new PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT modes
 834    which are no longer used.
 835  Eliminated the three new members of png_text when PNG_LEGACY_SUPPORTED is
 836    defined or when neither PNG_READ_iTXt_SUPPORTED nor PNG_WRITE_iTXt_SUPPORTED
 837    is defined.
 838  Made PNG_NO_READ|WRITE_iTXt the default setting, to avoid memory
 839    overrun when old applications fill the info_ptr->text structure directly.
 840  Added PNGAPI macro, and added it to the definitions of all exported functions.
 841  Relocated version macro definitions ahead of the includes of zlib.h and
 842    pngconf.h in png.h.
 843
 844Version 1.0.7beta12 [May 12, 2000]
 845  Revised pngset.c to avoid a problem with expanding the png_debug macro.
 846  Deleted some extraneous defines from pngconf.h
 847  Made PNG_NO_CONSOLE_IO the default condition when PNG_BUILD_DLL is defined.
 848  Use MSC _RPTn debugging instead of fprintf if _MSC_VER is defined.
 849  Added png_access_version_number() function.
 850  Check for mask&PNG_FREE_CHNK (for TEXT, SCAL, PCAL) in png_free_data().
 851  Expanded libpng.3/libpng.txt information about png_data_freer().
 852
 853Version 1.0.7beta14 [May 17, 2000] (beta13 was not published)
 854  Changed pnggccrd.c and pngvcrd.c to handle bad adaptive filter types as
 855    warnings instead of errors, as pngrutil.c does.
 856  Set the PNG_INFO_IDAT valid flag in png_set_rows() so png_write_png()
 857    will actually write IDATs.
 858  Made the default PNG_USE_LOCAL_ARRAYS depend on PNG_DLL instead of WIN32.
 859  Make png_free_data() ignore its final parameter except when freeing data
 860    that can have multiple instances (text, sPLT, unknowns).
 861  Fixed a new bug in png_set_rows().
 862  Removed info_ptr->valid tests from png_free_data(), as in version 1.0.5.
 863  Added png_set_invalid() function.
 864  Fixed incorrect illustrations of png_destroy_write_struct() in example.c.
 865
 866Version 1.0.7beta15 [May 30, 2000]
 867  Revised the deliberately erroneous Linux setjmp code in pngconf.h to produce
 868    fewer error messages.
 869  Rearranged checks for Z_OK to check the most likely path first in pngpread.c
 870    and pngwutil.c.
 871  Added checks in pngtest.c for png_create_*() returning NULL, and mentioned
 872    in libpng.txt/libpng.3 the need for applications to check this.
 873  Changed names of png_default_*() functions in pngtest to pngtest_*().
 874  Changed return type of png_get_x|y_offset_*() from png_uint_32 to png_int_32.
 875  Fixed some bugs in the unused PNG_INCH_CONVERSIONS functions in pngget.c
 876  Set each pointer to NULL after freeing it in png_free_data().
 877  Worked around a problem in pngconf.h; AIX's strings.h defines an "index"
 878    macro that conflicts with libpng's png_color_16.index. (Dimitri
 879    Papadapoulos)
 880  Added "msvc" directory with MSVC++ project files (Simon-Pierre Cadieux).
 881
 882Version 1.0.7beta16 [June 4, 2000]
 883  Revised the workaround of AIX string.h "index" bug.
 884  Added a check for overlength PLTE chunk in pngrutil.c.
 885  Added PNG_NO_POINTER_INDEXING macro to use array-indexing instead of pointer
 886    indexing in pngrutil.c and pngwutil.c to accommodate a buggy compiler.
 887  Added a warning in png_decompress_chunk() when it runs out of data, e.g.
 888    when it tries to read an erroneous PhotoShop iCCP chunk.
 889  Added PNG_USE_DLL macro.
 890  Revised the copyright/disclaimer/license notice.
 891  Added contrib/msvctest directory
 892
 893Version 1.0.7rc1 [June 9, 2000]
 894  Corrected the definition of PNG_TRANSFORM_INVERT_ALPHA  (0x0400 not 0x0200)
 895  Added contrib/visupng directory (Willem van Schaik)
 896
 897Version 1.0.7beta18 [June 23, 2000]
 898  Revised PNGAPI definition, and pngvcrd.c to work with __GCC__
 899    and do not redefine PNGAPI if it is passed in via a compiler directive.
 900  Revised visupng/PngFile.c to remove returns from within the Try block.
 901  Removed leading underscores from "_PNG_H" and "_PNG_SAVE_BSD_SOURCE" macros.
 902  Updated contrib/visupng/cexcept.h to version 1.0.0.
 903  Fixed bugs in pngwrite.c and pngwutil.c that prevented writing iCCP chunks.
 904
 905Version 1.0.7rc2 [June 28, 2000]
 906  Updated license to include disclaimers required by UCITA.
 907  Fixed "DJBPP" typo in pnggccrd.c introduced in beta18.
 908
 909Version 1.0.7 [July 1, 2000]
 910  Revised the definition of "trans_values" in libpng.3/libpng.txt
 911
 912Version 1.0.8beta1 [July 8, 2000]
 913  Added png_free(png_ptr, key) two places in pngpread.c to stop memory leaks.
 914  Changed PNG_NO_STDIO to PNG_NO_CONSOLE_IO, several places in pngrutil.c and
 915    pngwutil.c.
 916  Changed PNG_EXPORT_VAR to use PNG_IMPEXP, in pngconf.h.
 917  Removed unused "#include <assert.h>" from png.c
 918  Added WindowsCE support.
 919  Revised pnggccrd.c to work with gcc-2.95.2 and in the Cygwin environment.
 920
 921Version 1.0.8beta2 [July 10, 2000]
 922  Added project files to the wince directory and made further revisions
 923    of pngtest.c, pngrio.c, and pngwio.c in support of WindowsCE.
 924
 925Version 1.0.8beta3 [July 11, 2000]
 926  Only set the PNG_FLAG_FREE_TRNS or PNG_FREE_TRNS flag in png_handle_tRNS()
 927    for indexed-color input files to avoid potential double-freeing trans array
 928    under some unusual conditions; problem was introduced in version 1.0.6f.
 929  Further revisions to pngtest.c and files in the wince subdirectory.
 930
 931Version 1.0.8beta4 [July 14, 2000]
 932  Added the files pngbar.png and pngbar.jpg to the distribution.
 933  Added makefile.cygwin, and cygwin support in pngconf.h
 934  Added PNG_NO_ZALLOC_ZERO macro (makes png_zalloc skip zeroing memory)
 935
 936Version 1.0.8rc1 [July 16, 2000]
 937  Revised png_debug() macros and statements to eliminate compiler warnings.
 938
 939Version 1.0.8 [July 24, 2000]
 940  Added png_flush() in pngwrite.c, after png_write_IEND().
 941  Updated makefile.hpux to build a shared library.
 942
 943Version 1.0.9beta1 [November 10, 2000]
 944  Fixed typo in scripts/makefile.hpux
 945  Updated makevms.com in scripts and contrib/* and contrib/* (Martin Zinser)
 946  Fixed seqence-point bug in contrib/pngminus/png2pnm (Martin Zinser)
 947  Changed "cdrom.com" in documentation to "libpng.org"
 948  Revised pnggccrd.c to get it all working, and updated makefile.gcmmx (Greg).
 949  Changed type of "params" from voidp to png_voidp in png_read|write_png().
 950  Make sure PNGAPI and PNG_IMPEXP are defined in pngconf.h.
 951  Revised the 3 instances of WRITEFILE in pngtest.c.
 952  Relocated "msvc" and "wince" project subdirectories into "dll" subdirectory.
 953  Updated png.rc in dll/msvc project
 954  Revised makefile.dec to define and use LIBPATH and INCPATH
 955  Increased size of global png_libpng_ver[] array from 12 to 18 chars.
 956  Made global png_libpng_ver[], png_sig[] and png_pass_*[] arrays const.
 957  Removed duplicate png_crc_finish() from png_handle_bKGD() function.
 958  Added a warning when application calls png_read_update_info() multiple times.
 959  Revised makefile.cygwin
 960  Fixed bugs in iCCP support in pngrutil.c and pngwutil.c.
 961  Replaced png_set_empty_plte_permitted() with png_permit_mng_features().
 962
 963Version 1.0.9beta2 [November 19, 2000]
 964  Renamed the "dll" subdirectory "projects".
 965  Added borland project files to "projects" subdirectory.
 966  Set VS_FF_PRERELEASE and VS_FF_PATCHED flags in msvc/png.rc when appropriate.
 967  Add error message in png_set_compression_buffer_size() when malloc fails.
 968
 969Version 1.0.9beta3 [November 23, 2000]
 970  Revised PNG_LIBPNG_BUILD_TYPE macro in png.h, used in the msvc project.
 971  Removed the png_flush() in pngwrite.c that crashes some applications
 972    that don't set png_output_flush_fn.
 973  Added makefile.macosx and makefile.aix to scripts directory.
 974
 975Version 1.0.9beta4 [December 1, 2000]
 976  Change png_chunk_warning to png_warning in png_check_keyword().
 977  Increased the first part of msg buffer from 16 to 18 in png_chunk_error().
 978
 979Version 1.0.9beta5 [December 15, 2000]
 980  Added support for filter method 64 (for PNG datastreams embedded in MNG).
 981
 982Version 1.0.9beta6 [December 18, 2000]
 983  Revised png_set_filter() to accept filter method 64 when appropriate.
 984  Added new PNG_HAVE_PNG_SIGNATURE bit to png_ptr->mode and use it to
 985    help prevent applications from using MNG features in PNG datastreams.
 986  Added png_permit_mng_features() function.
 987  Revised libpng.3/libpng.txt.  Changed "filter type" to "filter method".
 988
 989Version 1.0.9rc1 [December 23, 2000]
 990  Revised test for PNG_HAVE_PNG_SIGNATURE in pngrutil.c
 991  Fixed error handling of unknown compression type in png_decompress_chunk().
 992  In pngconf.h, define __cdecl when _MSC_VER is defined.
 993
 994Version 1.0.9beta7 [December 28, 2000]
 995  Changed PNG_TEXT_COMPRESSION_zTXt to PNG_COMPRESSION_TYPE_BASE several places.
 996  Revised memory management in png_set_hIST and png_handle_hIST in a backward
 997    compatible manner.  PLTE and tRNS were revised similarly.
 998  Revised the iCCP chunk reader to ignore trailing garbage.
 999
1000Version 1.0.9beta8 [January 12, 2001]
1001  Moved pngasmrd.h into pngconf.h.
1002  Improved handling of out-of-spec garbage iCCP chunks generated by PhotoShop.
1003
1004Version 1.0.9beta9 [January 15, 2001]
1005  Added png_set_invalid, png_permit_mng_features, and png_mmx_supported to
1006    wince and msvc project module definition files.
1007  Minor revision of makefile.cygwin.
1008  Fixed bug with progressive reading of narrow interlaced images in pngpread.c
1009
1010Version 1.0.9beta10 [January 16, 2001]
1011  Do not typedef png_FILE_p in pngconf.h when PNG_NO_STDIO is defined.
1012  Fixed "png_mmx_supported" typo in project definition files.
1013
1014Version 1.0.9beta11 [January 19, 2001]
1015  Updated makefile.sgi to make shared library.
1016  Removed png_mmx_support() function and disabled PNG_MNG_FEATURES_SUPPORTED
1017    by default, for the benefit of DLL forward compatibility.  These will
1018    be re-enabled in version 1.2.0.
1019
1020Version 1.0.9rc2 [January 22, 2001]
1021  Revised cygwin support.
1022
1023Version 1.0.9 [January 31, 2001]
1024  Added check of cygwin's ALL_STATIC in pngconf.h
1025  Added "-nommx" parameter to contrib/gregbook/rpng2-win and rpng2-x demos.
1026
1027Version 1.0.10beta1 [March 14, 2001]
1028  Revised makefile.dec, makefile.sgi, and makefile.sggcc; added makefile.hpgcc.
1029  Reformatted libpng.3 to eliminate bad line breaks.
1030  Added checks for _mmx_supported in the read_filter_row function of pnggccrd.c
1031  Added prototype for png_mmx_support() near the top of pnggccrd.c
1032  Moved some error checking from png_handle_IHDR to png_set_IHDR.
1033  Added PNG_NO_READ_SUPPORTED and PNG_NO_WRITE_SUPPORTED macros.
1034  Revised png_mmx_support() function in pnggccrd.c
1035  Restored version 1.0.8 PNG_WRITE_EMPTY_PLTE_SUPPORTED behavior in pngwutil.c
1036  Fixed memory leak in contrib/visupng/PngFile.c
1037  Fixed bugs in png_combine_row() in pnggccrd.c and pngvcrd.c (C version)
1038  Added warnings when retrieving or setting gamma=0.
1039  Increased the first part of msg buffer from 16 to 18 in png_chunk_warning().
1040
1041Version 1.0.10rc1 [March 23, 2001]
1042  Changed all instances of memcpy, strcpy, and strlen to png_memcpy, png_strcpy,
1043    and png_strlen.
1044  Revised png_mmx_supported() function in pnggccrd.c to return proper value.
1045  Fixed bug in progressive reading (pngpread.c) with small images (height < 8).
1046
1047Version 1.0.10 [March 30, 2001]
1048  Deleted extraneous space (introduced in 1.0.9) from line 42 of makefile.cygwin
1049  Added beos project files (Chris Herborth)
1050
1051Version 1.0.11beta1 [April 3, 2001]
1052  Added type casts on several png_malloc() calls (Dimitri Papadapoulos).
1053  Removed a no-longer needed AIX work-around from pngconf.h
1054  Changed several "//" single-line comments to C-style in pnggccrd.c
1055
1056Version 1.0.11beta2 [April 11, 2001]
1057  Removed PNGAPI from several functions whose prototypes did not have PNGAPI.
1058  Updated scripts/pngos2.def
1059
1060Version 1.0.11beta3 [April 14, 2001]
1061  Added checking the results of many instances of png_malloc() for NULL
1062
1063Version 1.0.11beta4 [April 20, 2001]
1064  Undid the changes from version 1.0.11beta3.  Added a check for NULL return
1065    from user's malloc_fn().
1066  Removed some useless type casts of the NULL pointer.
1067  Added makefile.netbsd
1068
1069Version 1.0.11 [April 27, 2001]
1070  Revised makefile.netbsd
1071
1072Version 1.0.12beta1 [May 14, 2001]
1073  Test for Windows platform in pngconf.h when including malloc.h (Emmanuel Blot)
1074  Updated makefile.cygwin and handling of Cygwin's ALL_STATIC in pngconf.h
1075  Added some never-to-be-executed code in pnggccrd.c to quiet compiler warnings.
1076  Eliminated the png_error about apps using png_read|write_init().  Instead,
1077    libpng will reallocate the png_struct and info_struct if they are too small.
1078    This retains future binary compatibility for old applications written for
1079    libpng-0.88 and earlier.
1080
1081Version 1.2.0beta1 [May 6, 2001]
1082  Bumped DLLNUM to 2.
1083  Re-enabled PNG_MNG_FEATURES_SUPPORTED and enabled PNG_ASSEMBLER_CODE_SUPPORTED
1084    by default.
1085  Added runtime selection of MMX features.
1086  Added png_set_strip_error_numbers function and related macros.
1087
1088Version 1.2.0beta2 [May 7, 2001]
1089  Finished merging 1.2.0beta1 with version 1.0.11
1090  Added a check for attempts to read or write PLTE in grayscale PNG datastreams.
1091
1092Version 1.2.0beta3 [May 17, 2001]
1093  Enabled user memory function by default.
1094  Modified png_create_struct so it passes user mem_ptr to user memory allocator.
1095  Increased png_mng_features flag from png_byte to png_uint_32.
1096  Bumped shared-library (so-number) and dll-number to 3.
1097
1098Version 1.2.0beta4 [June 23, 2001]
1099  Check for missing profile length field in iCCP chunk and free chunk_data
1100    in case of truncated iCCP chunk.
1101  Bumped shared-library number to 3 in makefile.sgi and makefile.sggcc
1102  Bumped dll-number from 2 to 3 in makefile.cygwin
1103  Revised contrib/gregbook/rpng*-x.c to avoid a memory leak and to exit cleanly
1104    if user attempts to run it on an 8-bit display.
1105  Updated contrib/gregbook
1106  Use png_malloc instead of png_zalloc to allocate palette in pngset.c
1107  Updated makefile.ibmc
1108  Added some typecasts to eliminate gcc 3.0 warnings.  Changed prototypes
1109    of png_write_oFFS width and height from png_uint_32 to png_int_32.
1110  Updated example.c
1111  Revised prototypes for png_debug_malloc and png_debug_free in pngtest.c
1112
1113Version 1.2.0beta5 [August 8, 2001]
1114  Revised contrib/gregbook
1115  Revised makefile.gcmmx
1116  Revised pnggccrd.c to conditionally compile some thread-unsafe code only
1117    when PNG_THREAD_UNSAFE_OK is defined.
1118  Added tests to prevent pngwutil.c from writing a bKGD or tRNS chunk with
1119    value exceeding 2^bit_depth-1
1120  Revised makefile.sgi and makefile.sggcc
1121  Replaced calls to fprintf(stderr,...) with png_warning() in pnggccrd.c
1122  Removed restriction that do_invert_mono only operate on 1-bit opaque files
1123
1124Version 1.2.0 [September 1, 2001]
1125  Changed a png_warning() to png_debug() in pnggccrd.c
1126  Fixed contrib/gregbook/rpng-x.c, rpng2-x.c to avoid crash with XFreeGC().
1127
1128Version 1.2.1beta1 [October 19, 2001]
1129  Revised makefile.std in contrib/pngminus
1130  Include background_1 in png_struct regardless of gamma support.
1131  Revised makefile.netbsd and makefile.macosx, added makefile.darwin.
1132  Revised example.c to provide more details about using row_callback().
1133
1134Version 1.2.1beta2 [October 25, 2001]
1135  Added type cast to each NULL appearing in a function call, except for
1136    WINCE functions.
1137  Added makefile.so9.
1138
1139Version 1.2.1beta3 [October 27, 2001]
1140  Removed type casts from all NULLs.
1141  Simplified png_create_struct_2().
1142
1143Version 1.2.1beta4 [November 7, 2001]
1144  Revised png_create_info_struct() and png_creat_struct_2().
1145  Added error message if png_write_info() was omitted.
1146  Type cast NULLs appearing in function calls when _NO_PROTO or
1147    PNG_TYPECAST_NULL is defined.
1148
1149Version 1.2.1rc1 [November 24, 2001]
1150  Type cast NULLs appearing in function calls except when PNG_NO_TYPECAST_NULL
1151    is defined.
1152  Changed typecast of "size" argument to png_size_t in pngmem.c calls to
1153    the user malloc_fn, to agree with the prototype in png.h
1154  Added a pop/push operation to pnggccrd.c, to preserve Eflag (Maxim Sobolev)
1155  Updated makefile.sgi to recognize LIBPATH and INCPATH.
1156  Updated various makefiles so "make clean" does not remove previous major
1157    version of the shared library.
1158
1159Version 1.2.1rc2 [December 4, 2001]
1160  Always allocate 256-entry internal palette, hist, and trans arrays, to
1161    avoid out-of-bounds memory reference caused by invalid PNG datastreams.
1162  Added a check for prefix_length > data_length in iCCP chunk handler.
1163
1164Version 1.2.1 [December 7, 2001]
1165  None.
1166
1167Version 1.2.2beta1 [February 22, 2002]
1168  Fixed a bug with reading the length of iCCP profiles (Larry Reeves).
1169  Revised makefile.linux, makefile.gcmmx, and makefile.sgi to generate
1170    libpng.a, libpng12.so (not libpng.so.3), and libpng12/png.h
1171  Revised makefile.darwin to remove "-undefined suppress" option.
1172  Added checks for gamma and chromaticity values over 21474.83, which exceed
1173    the limit for PNG unsigned 32-bit integers when encoded.
1174  Revised calls to png_create_read_struct() and png_create_write_struct()
1175    for simpler debugging.
1176  Revised png_zalloc() so zlib handles errors (uses PNG_FLAG_MALLOC_NULL_MEM_OK)
1177
1178Version 1.2.2beta2 [February 23, 2002]
1179  Check chunk_length and idat_size for invalid (over PNG_MAX_UINT) lengths.
1180  Check for invalid image dimensions in png_get_IHDR.
1181  Added missing "fi;" in the install target of the SGI makefiles.
1182  Added install-static to all makefiles that make shared libraries.
1183  Always do gamma compensation when image is partially transparent.
1184
1185Version 1.2.2beta3 [March 7, 2002]
1186  Compute background.gray and background_1.gray even when color_type is RGB
1187    in case image gets reduced to gray later.
1188  Modified shared-library makefiles to install pkgconfig/libpngNN.pc.
1189  Export (with PNGAPI) png_zalloc, png_zfree, and png_handle_as_unknown
1190  Removed unused png_write_destroy_info prototype from png.h
1191  Eliminated incorrect use of width_mmx from pnggccrd.c in pixel_bytes == 8 case
1192  Added install-shared target to all makefiles that make shared libraries.
1193  Stopped a double free of palette, hist, and trans when not using free_me.
1194  Added makefile.32sunu for Sun Ultra 32 and makefile.64sunu for Sun Ultra 64.
1195
1196Version 1.2.2beta4 [March 8, 2002]
1197  Compute background.gray and background_1.gray even when color_type is RGB
1198    in case image gets reduced to gray later (Jason Summers).
1199  Relocated a misplaced /bin/rm in the "install-shared" makefile targets
1200  Added PNG_1_0_X macro which can be used to build a 1.0.x-compatible library.
1201
1202Version 1.2.2beta5 [March 26, 2002]
1203  Added missing PNGAPI to several function definitions.
1204  Check for invalid bit_depth or color_type in png_get_IHDR(), and
1205    check for missing PLTE or IHDR in png_push_read_chunk() (Matthias Clasen).
1206  Revised iTXt support to accept NULL for lang and lang_key.
1207  Compute gamma for color components of background even when color_type is gray.
1208  Changed "()" to "{}" in scripts/libpng.pc.in.
1209  Revised makefiles to put png.h and pngconf.h only in $prefix/include/libpngNN
1210  Revised makefiles to make symlink to libpng.so.NN in addition to libpngNN.so
1211
1212Version 1.2.2beta6 [March 31, 2002]
1213
1214Version 1.0.13beta1 [March 31, 2002]
1215  Prevent png_zalloc() from trying to memset memory that it failed to acquire.
1216  Add typecasts of PNG_MAX_UINT in pngset_cHRM_fixed() (Matt Holgate).
1217  Ensure that the right function (user or default) is used to free the
1218    png_struct after an error in png_create_read_struct_2().
1219
1220Version 1.2.2rc1 [April 7, 2002]
1221
1222Version 1.0.13rc1 [April 7, 2002]
1223  Save the ebx register in pnggccrd.c (Sami Farin)
1224  Add "mem_ptr = png_ptr->mem_ptr" in png_destroy_write_struct() (Paul Gardner).
1225  Updated makefiles to put headers in include/libpng and remove old include/*.h.
1226
1227Version 1.2.2 [April 15, 2002]
1228
1229Version 1.0.13 [April 15, 2002]
1230  Revised description of png_set_filter() in libpng.3/libpng.txt.
1231  Revised makefile.netbsd and added makefile.neNNbsd and makefile.freebsd
1232
1233Version 1.0.13patch01 [April 17, 2002]
1234
1235Version 1.2.2patch01 [April 17, 2002]
1236  Changed ${PNGMAJ}.${PNGVER} bug to ${PNGVER} in makefile.sgi and
1237    makefile.sggcc
1238  Fixed VER -> PNGVER typo in makefile.macosx and added install-static to
1239    install
1240  Added install: target to makefile.32sunu and makefile.64sunu
1241
1242Version 1.0.13patch03 [April 18, 2002]
1243
1244Version 1.2.2patch03 [April 18, 2002]
1245  Revised 15 makefiles to link libpng.a to libpngNN.a and the include libpng
1246  subdirectory to libpngNN subdirectory without the full pathname.
1247  Moved generation of libpng.pc from "install" to "all" in 15 makefiles.
1248
1249Version 1.2.3rc1 [April 28, 2002]
1250  Added install-man target to 15 makefiles (Dimitri Papadopolous-Orfanos).
1251  Added $(DESTDIR) feature to 24 makefiles (Tim Mooney)
1252  Fixed bug with $prefix, should be $(prefix) in makefile.hpux.
1253  Updated cygwin-specific portion of pngconf.h and revised makefile.cygwin
1254  Added a link from libpngNN.pc to libpng.pc in 15 makefiles.
1255  Added links from include/libpngNN/*.h to include/*.h in 24 makefiles.
1256  Revised makefile.darwin to make relative links without full pathname.
1257  Added setjmp() at the end of png_create_*_struct_2() in case user forgets
1258    to put one in their application.
1259  Restored png_zalloc() and png_zfree() prototypes to version 1.2.1 and
1260    removed them from module definition files.
1261
1262Version 1.2.3rc2 [May 1, 2002]
1263  Fixed bug in reporting number of channels in pngget.c and pngset.c,
1264    that was introduced in version 1.2.2beta5.
1265  Exported png_zalloc(), png_zfree(), png_default_read(), png_default_write(),
1266    png_default_flush(), and png_push_fill_buffer() and included them in
1267    module definition files.
1268  Added "libpng.pc" dependency to the "install-shared" target in 15 makefiles.
1269
1270Version 1.2.3rc3 [May 1, 2002]
1271  Revised prototype for png_default_flush()
1272  Remove old libpng.pc and libpngNN.pc before installing new ones.
1273
1274Version 1.2.3rc4 [May 2, 2002]
1275  Typos in *.def files (png_default_read|write -> png_default_read|write_data)
1276  In makefiles, changed rm libpng.NN.pc to rm libpngNN.pc
1277  Added libpng-config and libpngNN-config and modified makefiles to install
1278    them.
1279  Changed $(MANPATH) to $(DESTDIR)$(MANPATH) in makefiles
1280  Added "Win32 DLL VB" configuration to projects/msvc/libpng.dsp
1281
1282Version 1.2.3rc5 [May 11, 2002]
1283  Changed "error" and "message" in prototypes to "error_message" and
1284    "warning_message" to avoid namespace conflict.
1285  Revised 15 makefiles to build libpng-config from libpng-config-*.in
1286  Once more restored png_zalloc and png_zfree to regular nonexported form.
1287  Restored png_default_read|write_data, png_default_flush, png_read_fill_buffer
1288    to nonexported form, but with PNGAPI, and removed them from module def
1289    files.
1290
1291Version 1.2.3rc6 [May 14, 2002]
1292  Removed "PNGAPI" from png_zalloc() and png_zfree() in png.c
1293  Changed "Gz" to "Gd" in projects/msvc/libpng.dsp and zlib.dsp.
1294  Removed leftover libpng-config "sed" script from four makefiles.
1295  Revised libpng-config creating script in 16 makefiles.
1296
1297Version 1.2.3 [May 22, 2002]
1298  Revised libpng-config target in makefile.cygwin.
1299  Removed description of png_set_mem_fn() from documentation.
1300  Revised makefile.freebsd.
1301  Minor cosmetic changes to 15 makefiles, e.g., $(DI) = $(DESTDIR)/$(INCDIR).
1302  Revised projects/msvc/README.txt
1303  Changed -lpng to -lpngNN in LDFLAGS in several makefiles.
1304
1305Version 1.2.4beta1 [May 24, 2002]
1306  Added libpng.pc and libpng-config to "all:" target in 16 makefiles.
1307  Fixed bug in 16 makefiles: $(DESTDIR)/$(LIBPATH) to $(DESTDIR)$(LIBPATH)
1308  Added missing "\" before closing double quote in makefile.gcmmx.
1309  Plugged various memory leaks; added png_malloc_warn() and png_set_text_2()
1310    functions.
1311
1312Version 1.2.4beta2 [June 25, 2002]
1313  Plugged memory leak of png_ptr->current_text (Matt Holgate).
1314  Check for buffer overflow before reading CRC in pngpread.c (Warwick Allison)
1315  Added -soname to the loader flags in makefile.dec, makefile.sgi, and
1316    makefile.sggcc.
1317  Added "test-installed" target to makefile.linux, makefile.gcmmx,
1318    makefile.sgi, and makefile.sggcc.
1319
1320Version 1.2.4beta3 [June 28, 2002]
1321  Plugged memory leak of row_buf in pngtest.c when there is a png_error().
1322  Detect buffer overflow in pngpread.c when IDAT is corrupted with extra data.
1323  Added "test-installed" target to makefile.32sunu, makefile.64sunu,
1324    makefile.beos, makefile.darwin, makefile.dec, makefile.macosx,
1325    makefile.solaris, makefile.hpux, makefile.hpgcc, and makefile.so9.
1326
1327Version 1.2.4rc1 and 1.0.14rc1 [July 2, 2002]
1328  Added "test-installed" target to makefile.cygwin and makefile.sco.
1329  Revised pnggccrd.c to be able to back out version 1.0.x via PNG_1_0_X macro.
1330
1331Version 1.2.4 and 1.0.14 [July 8, 2002]
1332  Changed png_warning() to png_error() when width is too large to process.
1333
1334Version 1.2.4patch01 [July 20, 2002]
1335  Revised makefile.cygwin to use DLL number 12 instead of 13.
1336
1337Version 1.2.5beta1 [August 6, 2002]
1338  Added code to contrib/gregbook/readpng2.c to ignore unused chunks.
1339  Replaced toucan.png in contrib/gregbook (it has been corrupt since 1.0.11)
1340  Removed some stray *.o files from contrib/gregbook.
1341  Changed png_error() to png_warning() about "Too much data" in pngpread.c
1342    and about "Extra compressed data" in pngrutil.c.
1343  Prevent png_ptr->pass from exceeding 7 in png_push_finish_row().
1344  Updated makefile.hpgcc
1345  Updated png.c and pnggccrd.c handling of return from png_mmx_support()
1346
1347Version 1.2.5beta2 [August 15, 2002]
1348  Only issue png_warning() about "Too much data" in pngpread.c when avail_in
1349    is nonzero.
1350  Updated makefiles to install a separate libpng.so.3 with its own rpath.
1351
1352Version 1.2.5rc1 and 1.0.15rc1 [August 24, 2002]
1353  Revised makefiles to not remove previous minor versions of shared libraries.
1354
1355Version 1.2.5rc2 and 1.0.15rc2 [September 16, 2002]
1356  Revised 13 makefiles to remove "-lz" and "-L$(ZLIBLIB)", etc., from shared
1357    library loader directive.
1358  Added missing "$OBJSDLL" line to makefile.gcmmx.
1359  Added missing "; fi" to makefile.32sunu.
1360
1361Version 1.2.5rc3 and 1.0.15rc3 [September 18, 2002]
1362  Revised libpng-config script.
1363
1364Version 1.2.5 and 1.0.15 [October 3, 2002]
1365  Revised makefile.macosx, makefile.darwin, makefile.hpgcc, and makefile.hpux,
1366    and makefile.aix.
1367  Relocated two misplaced PNGAPI lines in pngtest.c
1368
1369Version 1.2.6beta1 [October 22, 2002]
1370  Commented out warning about uninitialized mmx_support in pnggccrd.c.
1371  Changed "IBMCPP__" flag to "__IBMCPP__" in pngconf.h.
1372  Relocated two more misplaced PNGAPI lines in pngtest.c
1373  Fixed memory overrun bug in png_do_read_filler() with 16-bit datastreams,
1374    introduced in version 1.0.2.
1375  Revised makefile.macosx, makefile.dec, makefile.aix, and makefile.32sunu.
1376
1377Version 1.2.6beta2 [November 1, 2002]
1378  Added libpng-config "--ldopts" output.
1379  Added "AR=ar" and "ARFLAGS=rc" and changed "ar rc" to "$(AR) $(ARFLAGS)"
1380    in makefiles.
1381
1382Version 1.2.6beta3 [July 18, 2004]
1383  Reverted makefile changes from version 1.2.6beta2 and some of the changes
1384    from version 1.2.6beta1; these will be postponed until version 1.2.7.
1385    Version 1.2.6 is going to be a simple bugfix release.
1386  Changed the one instance of "ln -sf" to "ln -f -s" in each Sun makefile.
1387  Fixed potential overrun in pngerror.c by using strncpy instead of memcpy.
1388  Added "#!/bin/sh" at the top of configure, for recognition of the
1389    'x' flag under Cygwin (Cosmin).
1390  Optimized vacuous tests that silence compiler warnings, in png.c (Cosmin).
1391  Added support for PNG_USER_CONFIG, in pngconf.h (Cosmin).
1392  Fixed the special memory handler for Borland C under DOS, in pngmem.c
1393    (Cosmin).
1394  Removed some spurious assignments in pngrutil.c (Cosmin).
1395  Replaced 65536 with 65536L, and 0xffff with 0xffffL, to silence warnings
1396    on 16-bit platforms (Cosmin).
1397  Enclosed shift op expressions in parentheses, to silence warnings (Cosmin).
1398  Used proper type png_fixed_point, to avoid problems on 16-bit platforms,
1399    in png_handle_sRGB() (Cosmin).
1400  Added compression_type to png_struct, and optimized the window size
1401    inside the deflate stream (Cosmin).
1402  Fixed definition of isnonalpha(), in pngerror.c and pngrutil.c (Cosmin).
1403  Fixed handling of unknown chunks that come after IDAT (Cosmin).
1404  Allowed png_error() and png_warning() to work even if png_ptr == NULL
1405    (Cosmin).
1406  Replaced row_info->rowbytes with row_bytes in png_write_find_filter()
1407    (Cosmin).
1408  Fixed definition of PNG_LIBPNG_VER_DLLNUM (Simon-Pierre).
1409  Used PNG_LIBPNG_VER and PNG_LIBPNG_VER_STRING instead of the hardcoded
1410    values in png.c (Simon-Pierre, Cosmin).
1411  Initialized png_libpng_ver[] with PNG_LIBPNG_VER_STRING (Simon-Pierre).
1412  Replaced PNG_LIBPNG_VER_MAJOR with PNG_LIBPNG_VER_DLLNUM in png.rc
1413    (Simon-Pierre).
1414  Moved the definition of PNG_HEADER_VERSION_STRING near the definitions
1415    of the other PNG_LIBPNG_VER_... symbols in png.h (Cosmin).
1416  Relocated #ifndef PNGAPI guards in pngconf.h (Simon-Pierre, Cosmin).
1417  Updated scripts/makefile.vc(a)win32 (Cosmin).
1418  Updated the MSVC project (Simon-Pierre, Cosmin).
1419  Updated the Borland C++ Builder project (Cosmin).
1420  Avoided access to asm_flags in pngvcrd.c, if PNG_1_0_X is defined (Cosmin).
1421  Commented out warning about uninitialized mmx_support in pngvcrd.c (Cosmin).
1422  Removed scripts/makefile.bd32 and scripts/pngdef.pas (Cosmin).
1423  Added extra guard around inclusion of Turbo C memory headers, in pngconf.h
1424    (Cosmin).
1425  Renamed projects/msvc/ to projects/visualc6/, and projects/borland/ to
1426    projects/cbuilder5/ (Cosmin).
1427  Moved projects/visualc6/png32ms.def to scripts/pngw32.def,
1428    and projects/visualc6/png.rc to scripts/pngw32.rc (Cosmin).
1429  Added projects/visualc6/pngtest.dsp; removed contrib/msvctest/ (Cosmin).
1430  Changed line endings to DOS style in cbuilder5 and visualc6 files, even
1431    in the tar.* distributions (Cosmin).
1432  Updated contrib/visupng/VisualPng.dsp (Cosmin).
1433  Updated contrib/visupng/cexcept.h to version 2.0.0 (Cosmin).
1434  Added a separate distribution with "configure" and supporting files (Junichi).
1435
1436Version 1.2.6beta4 [July 28, 2004]
1437  Added user ability to change png_size_t via a PNG_SIZE_T macro.
1438  Added png_sizeof() and png_convert_size() functions.
1439  Added PNG_SIZE_MAX (maximum value of a png_size_t variable.
1440  Added check in png_malloc_default() for (size_t)size != (png_uint_32)size
1441    which would indicate an overflow.
1442  Changed sPLT failure action from png_error to png_warning and abandon chunk.
1443  Changed sCAL and iCCP failures from png_error to png_warning and abandon.
1444  Added png_get_uint_31(png_ptr, buf) function.
1445  Added PNG_UINT_32_MAX macro.
1446  Renamed PNG_MAX_UINT to PNG_UINT_31_MAX.
1447  Made png_zalloc() issue a png_warning and return NULL on potential
1448    overflow.
1449  Turn on PNG_NO_ZALLOC_ZERO by default in version 1.2.x
1450  Revised "clobber list" in pnggccrd.c so it will compile under gcc-3.4.
1451  Revised Borland portion of png_malloc() to return NULL or issue
1452    png_error() according to setting of PNG_FLAG_MALLOC_NULL_MEM_OK.
1453  Added PNG_NO_SEQUENTIAL_READ_SUPPORTED macro to conditionally remove
1454    sequential read support.
1455  Added some "#if PNG_WRITE_SUPPORTED" blocks.
1456  Added #ifdef to remove some redundancy in png_malloc_default().
1457  Use png_malloc instead of png_zalloc to allocate the pallete.
1458
1459Version 1.0.16rc1 and 1.2.6rc1 [August 4, 2004]
1460  Fixed buffer overflow vulnerability (CVE-2004-0597) in png_handle_tRNS().
1461  Fixed NULL dereference vulnerability (CVE-2004-0598) in png_handle_iCCP().
1462  Fixed integer overflow vulnerability (CVE-2004-0599) in png_read_png().
1463  Fixed some harmless bugs in png_handle_sBIT, etc, that would cause
1464    duplicate chunk types to go undetected.
1465  Fixed some timestamps in the -config version
1466  Rearranged order of processing of color types in png_handle_tRNS().
1467  Added ROWBYTES macro to calculate rowbytes without integer overflow.
1468  Updated makefile.darwin and removed makefile.macosx from scripts directory.
1469  Imposed default one million column, one-million row limits on the image
1470    dimensions, and added png_set_user_limits() function to override them.
1471  Revised use of PNG_SET_USER_LIMITS_SUPPORTED macro.
1472  Fixed wrong cast of returns from png_get_user_width|height_max().
1473  Changed some "keep the compiler happy" from empty statements to returns,
1474  Revised libpng.txt to remove 1.2.x stuff from the 1.0.x distribution
1475
1476Version 1.0.16rc2 and 1.2.6rc2 [August 7, 2004]
1477  Revised makefile.darwin and makefile.solaris.  Removed makefile.macosx.
1478  Revised pngtest's png_debug_malloc() to use png_malloc() instead of
1479    png_malloc_default() which is not supposed to be exported.
1480  Fixed off-by-one error in one of the conversions to PNG_ROWBYTES() in
1481    pngpread.c.  Bug was introduced in 1.2.6rc1.
1482  Fixed bug in RGB to RGBX transformation introduced in 1.2.6rc1.
1483  Fixed old bug in RGB to Gray transformation.
1484  Fixed problem with 64-bit compilers by casting arguments to abs()
1485    to png_int_32.
1486  Changed "ln -sf" to "ln -f -s" in three makefiles (solaris, sco, so9).
1487  Changed "HANDLE_CHUNK_*" to "PNG_HANDLE_CHUNK_*" (Cosmin)
1488  Added "-@/bin/rm -f $(DL)/$(LIBNAME).so.$(PNGMAJ)" to 15 *NIX makefiles.
1489  Added code to update the row_info->colortype in png_do_read_filler() (MSB).
1490
1491Version 1.0.16rc3 and 1.2.6rc3 [August 9, 2004]
1492  Eliminated use of "abs()" in testing cHRM and gAMA values, to avoid
1493    trouble with some 64-bit compilers.  Created PNG_OUT_OF_RANGE() macro.
1494  Revised documentation of png_set_keep_unknown_chunks().
1495  Check handle_as_unknown status in pngpread.c, as in pngread.c previously.
1496  Moved  "PNG_HANDLE_CHUNK_*" macros out of PNG_INTERNAL section of png.h
1497  Added "rim" definitions for CONST4 and CONST6 in pnggccrd.c
1498
1499Version 1.0.16rc4 and 1.2.6rc4 [August 10, 2004]
1500  Fixed mistake in pngtest.c introduced in 1.2.6rc2 (declaration of
1501    "pinfo" was out of place).
1502
1503Version 1.0.16rc5 and 1.2.6rc5 [August 10, 2004]
1504  Moved  "PNG_HANDLE_CHUNK_*" macros out of PNG_ASSEMBLER_CODE_SUPPORTED
1505    section of png.h where they were inadvertently placed in version rc3.
1506
1507Version 1.2.6 and 1.0.16 [August 15, 2004]
1508  Revised pngtest so memory allocation testing is only done when PNG_DEBUG==1.
1509
1510Version 1.2.7beta1 [August 26, 2004]
1511  Removed unused pngasmrd.h file.
1512  Removed references to uu.net for archived files.  Added references to
1513    PNG Spec (second edition) and the PNG ISO/IEC Standard.
1514  Added "test-dd" target in 15 makefiles, to run pngtest in DESTDIR.
1515  Fixed bug with "optimized window size" in the IDAT datastream, that
1516    causes libpng to write PNG files with incorrect zlib header bytes.
1517
1518Version 1.2.7beta2 [August 28, 2004]
1519  Fixed bug with sCAL chunk and big-endian machines (David Munro).
1520  Undid new code added in 1.2.6rc2 to update the color_type in
1521    png_set_filler().
1522  Added png_set_add_alpha() that updates color type.
1523
1524Version 1.0.17rc1 and 1.2.7rc1 [September 4, 2004]
1525  Revised png_set_strip_filler() to not remove alpha if color_type has alpha.
1526
1527Version 1.2.7 and 1.0.17 [September 12, 2004]
1528  Added makefile.hp64
1529  Changed projects/msvc/png32ms.def to scripts/png32ms.def in makefile.cygwin
1530
1531Version 1.2.8beta1 [November 1, 2004]
1532  Fixed bug in png_text_compress() that would fail to complete a large block.
1533  Fixed bug, introduced in libpng-1.2.7, that overruns a buffer during
1534    strip alpha operation in png_do_strip_filler().
1535  Added PNG_1_2_X definition in pngconf.h
1536  Use #ifdef to comment out png_info_init in png.c and png_read_init in
1537    pngread.c (as of 1.3.0)
1538
1539Version 1.2.8beta2 [November 2, 2004]
1540  Reduce color_type to a nonalpha type after strip alpha operation in
1541    png_do_strip_filler().
1542
1543Version 1.2.8beta3 [November 3, 2004]
1544  Revised definitions of PNG_MAX_UINT_32, PNG_MAX_SIZE, and PNG_MAXSUM
1545
1546Version 1.2.8beta4 [November 12, 2004]
1547  Fixed (again) definition of PNG_LIBPNG_VER_DLLNUM in png.h (Cosmin).
1548  Added PNG_LIBPNG_BUILD_PRIVATE in png.h (Cosmin).
1549  Set png_ptr->zstream.data_type to Z_BINARY, to avoid unnecessary detection
1550    of data type in deflate (Cosmin).
1551  Deprecated but continue to support SPECIALBUILD and PRIVATEBUILD in favor of
1552    PNG_LIBPNG_BUILD_SPECIAL_STRING and PNG_LIBPNG_BUILD_PRIVATE_STRING.
1553
1554Version 1.2.8beta5 [November 20, 2004]
1555  Use png_ptr->flags instead of png_ptr->transformations to pass
1556    PNG_STRIP_ALPHA info to png_do_strip_filler(), to preserve ABI
1557    compatibility.
1558  Revised handling of SPECIALBUILD, PRIVATEBUILD,
1559    PNG_LIBPNG_BUILD_SPECIAL_STRING and PNG_LIBPNG_BUILD_PRIVATE_STRING.
1560
1561Version 1.2.8rc1 [November 24, 2004]
1562  Moved handling of BUILD macros from pngconf.h to png.h
1563  Added definition of PNG_LIBPNG_BASE_TYPE in png.h, inadvertently
1564    omitted from beta5.
1565  Revised scripts/pngw32.rc
1566  Despammed mailing addresses by masking "@" with "at".
1567  Inadvertently installed a supposedly faster test version of pngrutil.c
1568
1569Version 1.2.8rc2 [November 26, 2004]
1570  Added two missing "\" in png.h
1571  Change tests in pngread.c and pngpread.c to
1572    if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
1573       png_do_read_transformations(png_ptr);
1574
1575Version 1.2.8rc3 [November 28, 2004]
1576  Reverted pngrutil.c to version libpng-1.2.8beta5.
1577  Added scripts/makefile.elf with supporting code in pngconf.h for symbol
1578    versioning (John Bowler).
1579
1580Version 1.2.8rc4 [November 29, 2004]
1581  Added projects/visualc7 (Simon-pierre).
1582
1583Version 1.2.8rc5 [November 29, 2004]
1584  Fixed new typo in scripts/pngw32.rc
1585
1586Version 1.2.8 [December 3, 2004]
1587  Removed projects/visualc7, added projects/visualc71.
1588
1589Version 1.2.9beta1 [February 21, 2006]
1590  Initialized some structure members in pngwutil.c to avoid gcc-4.0.0 complaints
1591  Revised man page and libpng.txt to make it clear that one should not call
1592    png_read_end or png_write_end after png_read_png or png_write_png.
1593  Updated references to png-mng-implement mailing list.
1594  Fixed an incorrect typecast in pngrutil.c
1595  Added PNG_NO_READ_SUPPORTED conditional for making a write-only library.
1596  Added PNG_NO_WRITE_INTERLACING_SUPPORTED conditional.
1597  Optimized alpha-inversion loops in pngwtran.c
1598  Moved test for nonzero gamma outside of png_build_gamma_table() in pngrtran.c
1599  Make sure num_trans is <= 256 before copying data in png_set_tRNS().
1600  Make sure num_palette is <= 256 before copying data in png_set_PLTE().
1601  Interchanged order of write_swap_alpha and write_invert_alpha transforms.
1602  Added parentheses in the definition of PNG_LIBPNG_BUILD_TYPE (Cosmin).
1603  Optimized zlib window flag (CINFO) in contrib/pngsuite/*.png (Cosmin).
1604  Updated scripts/makefile.bc32 for Borland C++ 5.6 (Cosmin).
1605  Exported png_get_uint_32, png_save_uint_32, png_get_uint_16, png_save_uint_16,
1606    png_get_int_32, png_save_int_32, png_get_uint_31 (Cosmin).
1607  Added type cast (png_byte) in png_write_sCAL() (Cosmin).
1608  Fixed scripts/makefile.cygwin (Christian Biesinger, Cosmin).
1609  Default iTXt support was inadvertently enabled.
1610
1611Version 1.2.9beta2 [February 21, 2006]
1612  Check for png_rgb_to_gray and png_gray_to_rgb read transformations before
1613    checking for png_read_dither in pngrtran.c
1614  Revised checking of chromaticity limits to accommodate extended RGB
1615    colorspace (John Denker).
1616  Changed line endings in some of the project files to CRLF, even in the
1617    "Unix" tar distributions (Cosmin).
1618  Made png_get_int_32 and png_save_int_32 always available (Cosmin).
1619  Updated scripts/pngos2.def, scripts/pngw32.def and projects/wince/png32ce.def
1620    with the newly exported functions.
1621  Eliminated distributions without the "configure" script.
1622  Updated INSTALL instructions.
1623
1624Version 1.2.9beta3 [February 24, 2006]
1625  Fixed CRCRLF line endings in contrib/visupng/VisualPng.dsp
1626  Made libpng.pc respect EXEC_PREFIX (D. P. Kreil, J. Bowler)
1627  Removed reference to pngasmrd.h from Makefile.am
1628  Renamed CHANGES to ChangeLog.
1629  Renamed LICENSE to COPYING.
1630  Renamed ANNOUNCE to NEWS.
1631  Created AUTHORS file.
1632
1633Version 1.2.9beta4 [March 3, 2006]
1634  Changed definition of PKGCONFIG from $prefix/lib to $libdir in configure.ac
1635  Reverted to filenames LICENSE and ANNOUNCE; removed AUTHORS and COPYING.
1636  Removed newline from the end of some error and warning messages.
1637  Removed test for sqrt() from configure.ac and configure.
1638  Made swap tables in pngtrans.c PNG_CONST (Carlo Bramix).
1639  Disabled default iTXt support that was inadvertently enabled in
1640    libpng-1.2.9beta1.
1641  Added "OS2" to list of systems that don't need underscores, in pnggccrd.c
1642  Removed libpng version and date from *.c files.
1643
1644Version 1.2.9beta5 [March 4, 2006]
1645  Removed trailing blanks from source files.
1646  Put version and date of latest change in each source file, and changed
1647    copyright year accordingly.
1648  More cleanup of configure.ac, Makefile.am, and associated scripts.
1649  Restored scripts/makefile.elf which was inadvertently deleted.
1650
1651Version 1.2.9beta6 [March 6, 2006]
1652  Fixed typo (RELEASE) in configuration files.
1653
1654Version 1.2.9beta7 [March 7, 2006]
1655  Removed libpng.vers and libpng.sym from libpng12_la_SOURCES in Makefile.am
1656  Fixed inconsistent #ifdef's around png_sig_bytes() and png_set_sCAL_s()
1657    in png.h.
1658  Updated makefile.elf as suggested by debian.
1659  Made cosmetic changes to some makefiles, adding LN_SF and other macros.
1660  Made some makefiles accept "exec_prefix".
1661
1662Version 1.2.9beta8 [March 9, 2006]
1663  Fixed some "#if defined (..." which should be "#if defined(..."
1664    Bug introduced in libpng-1.2.8.
1665  Fixed inconsistency in definition of png_default_read_data()
1666  Restored blank that was lost from makefile.sggcc "clean" target in beta7.
1667  Revised calculation of "current" and "major" for irix in ltmain.sh
1668  Changed "mkdir" to "MKDIR_P" in some makefiles.
1669  Separated PNG_EXPAND and PNG_EXPAND_tRNS.
1670  Added png_set_expand_gray_1_2_4_to_8() and deprecated
1671    png_set_gray_1_2_4_to_8() which also expands tRNS to alpha.
1672
1673Version 1.2.9beta9 [March 10, 2006]
1674  Include "config.h" in pngconf.h when available.
1675  Added some checks for NULL png_ptr or NULL info_ptr (timeless)
1676
1677Version 1.2.9beta10 [March 20, 2006]
1678  Removed extra CR from contrib/visualpng/VisualPng.dsw (Cosmin)
1679  Made pnggccrd.c PIC-compliant (Christian Aichinger).
1680  Added makefile.mingw (Wolfgang Glas).
1681  Revised pngconf.h MMX checking.
1682
1683Version 1.2.9beta11 [March 22, 2006]
1684  Fixed out-of-order declaration in pngwrite.c that was introduced in beta9
1685  Simplified some makefiles by using LIBSO, LIBSOMAJ, and LIBSOVER macros.
1686
1687Version 1.2.9rc1 [March 31, 2006]
1688  Defined PNG_USER_PRIVATEBUILD when including "pngusr.h" (Cosmin).
1689  Removed nonsensical assertion check from pngtest.c (Cosmin).
1690
1691Version 1.2.9 [April 14, 2006]
1692  Revised makefile.beos and added "none" selector in ltmain.sh
1693
1694Version 1.2.10beta1 [April 15, 2006]
1695  Renamed "config.h" to "png_conf.h" and revised Makefile.am to add
1696    -DPNG_BUILDING_LIBPNG to compile directive, and modified pngconf.h
1697    to include png_conf.h only when PNG_BUILDING_LIBPNG is defined.
1698
1699Version 1.2.10beta2 [April 15, 2006]
1700  Manually updated Makefile.in and configure.  Changed png_conf.h.in
1701    back to config.h.
1702
1703Version 1.2.10beta3 [April 15, 2006]
1704  Change png_conf.h back to config.h in pngconf.h.
1705
1706Version 1.2.10beta4 [April 16, 2006]
1707  Change PNG_BUILDING_LIBPNG to PNG_CONFIGURE_LIBPNG in config/Makefile*.
1708
1709Version 1.2.10beta5 [April 16, 2006]
1710  Added a configure check for compiling assembler code in pnggccrd.c
1711
1712Version 1.2.10beta6 [April 17, 2006]
1713  Revised the configure check for pnggccrd.c
1714  Moved -DPNG_CONFIGURE_LIBPNG into @LIBPNG_DEFINES@
1715  Added @LIBPNG_DEFINES@ to arguments when building libpng.sym
1716
1717Version 1.2.10beta7 [April 18, 2006]
1718  Change "exec_prefix=$prefix" to "exec_prefix=$(prefix)" in makefiles.
1719
1720Version 1.2.10rc1 [April 19, 2006]
1721  Ensure pngconf.h doesn't define both PNG_USE_PNGGCCRD and PNG_USE_PNGVCRD
1722  Fixed "LN_FS" typo in makefile.sco and makefile.solaris.
1723
1724Version 1.2.10rc2 [April 20, 2006]
1725  Added a backslash between -DPNG_CONFIGURE_LIBPNG and -DPNG_NO_ASSEMBLER_CODE
1726   in configure.ac and configure
1727  Made the configure warning about versioned symbols less arrogant.
1728
1729Version 1.2.10rc3 [April 21, 2006]
1730  Added a note in libpng.txt that png_set_sig_bytes(8) can be used when
1731    writing an embedded PNG without the 8-byte signature.
1732  Revised makefiles and configure to avoid making links to libpng.so.*
1733
1734Version 1.2.10 [April 23, 2006]
1735  Reverted configure to "rc2" state.
1736
1737Version 1.2.11beta1 [May 31, 2006]
1738  scripts/libpng.pc.in contained "configure" style version info and would
1739    not work with makefiles.
1740  The shared-library makefiles were linking to libpng.so.0 instead of
1741    libpng.so.3 compatibility as the library.
1742
1743Version 1.2.11beta2 [June 2, 2006]
1744  Increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
1745    buffer overflow.
1746  Fixed bug in example.c (png_set_palette_rgb -> png_set_palette_to_rgb)
1747
1748Version 1.2.11beta3 [June 5, 2006]
1749  Prepended "#! /bin/sh" to ltmail.sh and contrib/pngminus/*.sh (Cosmin).
1750  Removed the accidental leftover Makefile.in~ (Cosmin).
1751  Avoided potential buffer overflow and optimized buffer in
1752    png_write_sCAL(), png_write_sCAL_s() (Cosmin).
1753  Removed the include directories and libraries from CFLAGS and LDFLAGS
1754    in scripts/makefile.gcc (Nelson A. de Oliveira, Cosmin).
1755
1756Version 1.2.11beta4 [June 6, 2006]
1757  Allow zero-length IDAT chunks after the entire zlib datastream, but not
1758    after another intervening chunk type.
1759
1760Version 1.0.19rc1, 1.2.11rc1 [June 13, 2006]
1761  Deleted extraneous square brackets from [config.h] in configure.ac
1762
1763Version 1.0.19rc2, 1.2.11rc2 [June 14, 2006]
1764  Added prototypes for PNG_INCH_CONVERSIONS functions to png.h
1765  Revised INSTALL and autogen.sh
1766  Fixed typo in several makefiles (-W1 should be -Wl)
1767  Added typedef for png_int_32 and png_uint_32 on 64-bit systems.
1768
1769Version 1.0.19rc3, 1.2.11rc3 [June 15, 2006]
1770  Removed the new typedefs for 64-bit systems (delay until version 1.4.0)
1771  Added one zero element to png_gamma_shift[] array in pngrtran.c to avoid
1772    reading out of bounds.
1773
1774Version 1.0.19rc4, 1.2.11rc4 [June 15, 2006]
1775  Really removed the new typedefs for 64-bit systems.
1776
1777Version 1.0.19rc5, 1.2.11rc5 [June 22, 2006]
1778  Removed png_sig_bytes entry from scripts/pngw32.def
1779
1780Version 1.0.19, 1.2.11 [June 26, 2006]
1781  None.
1782
1783Version 1.0.20, 1.2.12 [June 27, 2006]
1784  Really increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
1785    buffer overflow.
1786
1787Version 1.2.13beta1 [October 2, 2006]
1788  Removed AC_FUNC_MALLOC from configure.ac
1789  Work around Intel-Mac compiler bug by setting PNG_NO_MMX_CODE in pngconf.h
1790  Change "logical" to "bitwise" throughout documentation.
1791  Detect and fix attempt to write wrong iCCP profile length (CVE-2006-7244)
1792
1793Version 1.0.21, 1.2.13 [November 14, 2006]
1794  Fix potential buffer overflow in sPLT chunk handler.
1795  Fix Makefile.am to not try to link to noexistent files.
1796  Check all exported functions for NULL png_ptr.
1797
1798Version 1.2.14beta1 [November 17, 2006]
1799  Relocated three misplaced tests for NULL png_ptr.
1800  Built Makefile.in with automake-1.9.6 instead of 1.9.2.
1801  Build configure with autoconf-2.60 instead of 2.59
1802
1803Version 1.2.14beta2 [November 17, 2006]
1804  Added some typecasts in png_zalloc().
1805
1806Version 1.2.14rc1 [November 20, 2006]
1807  Changed "strtod" to "png_strtod" in pngrutil.c
1808
1809Version 1.0.22, 1.2.14    [November 27, 2006]
1810  Added missing "$(srcdir)" in Makefile.am and Makefile.in
1811
1812Version 1.2.15beta1 [December 3, 2006]
1813  Generated configure with autoconf-2.61 instead of 2.60
1814  Revised configure.ac to update libpng.pc and libpng-config.
1815
1816Version 1.2.15beta2 [December 3, 2006]
1817  Always export MMX asm functions, just stubs if not building pnggccrd.c
1818
1819Version 1.2.15beta3 [December 4, 2006]
1820  Add "png_bytep" typecast to profile while calculating length in pngwutil.c
1821
1822Version 1.2.15beta4 [December 7, 2006]
1823  Added scripts/CMakeLists.txt
1824  Changed PNG_NO_ASSEMBLER_CODE to PNG_NO_MMX_CODE in scripts, like 1.4.0beta
1825
1826Version 1.2.15beta5 [December 7, 2006]
1827  Changed some instances of PNG_ASSEMBLER_* to PNG_MMX_* in pnggccrd.c
1828  Revised scripts/CMakeLists.txt
1829
1830Version 1.2.15beta6 [December 13, 2006]
1831  Revised scripts/CMakeLists.txt and configure.ac
1832
1833Version 1.2.15rc1 [December 18, 2006]
1834  Revised scripts/CMakeLists.txt
1835
1836Version 1.2.15rc2 [December 21, 2006]
1837  Added conditional #undef jmpbuf in pngtest.c to undo #define in AIX headers.
1838  Added scripts/makefile.nommx
1839
1840Version 1.2.15rc3 [December 25, 2006]
1841  Fixed shared library numbering error that was introduced in 1.2.15beta6.
1842
1843Version 1.2.15rc4 [December 27, 2006]
1844  Fixed handling of rgb_to_gray when png_ptr->color.gray isn't set.
1845
1846Version 1.2.15rc5 [December 31, 2006]
1847  Revised handling of rgb_to_gray.
1848
1849Version 1.2.15 [January 5, 2007]
1850  Added some (unsigned long) typecasts in pngtest.c to avoid printing errors.
1851
1852Version 1.2.16beta1 [January 6, 2007]
1853  Fix bugs in makefile.nommx
1854
1855Version 1.2.16beta2 [January 16, 2007]
1856  Revised scripts/CMakeLists.txt
1857
1858Version 1.2.16 [January 31, 2007]
1859  No changes.
1860
1861Version 1.2.17beta1 [March 6, 2007]
1862  Revised scripts/CMakeLists.txt to install both shared and static libraries.
1863  Deleted a redundant line from pngset.c.
1864
1865Version 1.2.17beta2 [April 26, 2007]
1866  Relocated misplaced test for png_ptr == NULL in pngpread.c
1867  Change "==" to "&" for testing PNG_RGB_TO_GRAY_ERR & PNG_RGB_TO_GRAY_WARN
1868    flags.
1869  Changed remaining instances of PNG_ASSEMBLER_* to PNG_MMX_*
1870  Added pngerror() when write_IHDR fails in deflateInit2().
1871  Added "const" to some array declarations.
1872  Mention examples of libpng usage in the libpng*.txt and libpng.3 documents.
1873
1874Version 1.2.17rc1 [May 4, 2007]
1875  No changes.
1876
1877Version 1.2.17rc2 [May 8, 2007]
1878  Moved several PNG_HAVE_* macros out of PNG_INTERNAL because applications
1879    calling set_unknown_chunk_location() need them.
1880  Changed transformation flag from PNG_EXPAND_tRNS to PNG_EXPAND in
1881    png_set_expand_gray_1_2_4_to_8().
1882  Added png_ptr->unknown_chunk to hold working unknown chunk data, so it
1883    can be free'ed in case of error.  Revised unknown chunk handling in
1884    pngrutil.c and pngpread.c to use this structure.
1885
1886Version 1.2.17rc3 [May 8, 2007]
1887  Revised symbol-handling in configure script.
1888
1889Version 1.2.17rc4 [May 10, 2007]
1890  Revised unknown chunk handling to avoid storing unknown critical chunks.
1891
1892Version 1.0.25 [May 15, 2007]
1893Version 1.2.17 [May 15, 2007]
1894  Added "png_ptr->num_trans=0" before error return in png_handle_tRNS,
1895    to eliminate a vulnerability (CVE-2007-2445, CERT VU#684664)
1896
1897Version 1.0.26 [May 15, 2007]
1898Version 1.2.18 [May 15, 2007]
1899  Reverted the libpng-1.2.17rc3 change to symbol-handling in configure script
1900
1901Version 1.2.19beta1 [May 18, 2007]
1902  Changed "const static" to "static PNG_CONST" everywhere, mostly undoing
1903    change of libpng-1.2.17beta2.  Changed other "const" to "PNG_CONST"
1904  Changed some handling of unused parameters, to avoid compiler warnings.
1905    "if (unused == NULL) return;" becomes "unused = unused".
1906
1907Version 1.2.19beta2 [May 18, 2007]
1908  Only use the valid bits of tRNS value in png_do_expand() (Brian Cartier)
1909
1910Version 1.2.19beta3 [May 19, 2007]
1911  Add some "png_byte" typecasts in png_check_keyword() and write new_key
1912  instead of key in zTXt chunk (Kevin Ryde).
1913
1914Version 1.2.19beta4 [May 21, 2007]
1915  Add png_snprintf() function and use it in place of sprint() for improved
1916    defense against buffer overflows.
1917
1918Version 1.2.19beta5 [May 21, 2007]
1919  Fixed png_handle_tRNS() to only use the valid bits of tRNS value.
1920  Changed handling of more unused parameters, to avoid compiler warnings.
1921  Removed some PNG_CONST in pngwutil.c to avoid compiler warnings.
1922
1923Version 1.2.19beta6 [May 22, 2007]
1924  Added some #ifdef PNG_MMX_CODE_SUPPORTED where needed in pngvcrd.c
1925  Added a special "_MSC_VER" case that defines png_snprintf to _snprintf
1926
1927Version 1.2.19beta7 [May 22, 2007]
1928  Squelched png_squelch_warnings() in pnggccrd.c and added
1929    an #ifdef PNG_MMX_CODE_SUPPORTED block around the declarations that caused
1930    the warnings that png_squelch_warnings was squelching.
1931
1932Version 1.2.19beta8 [May 22, 2007]
1933  Removed __MMX__ from test in pngconf.h.
1934
1935Version 1.2.19beta9 [May 23, 2007]
1936  Made png_squelch_warnings() available via PNG_SQUELCH_WARNINGS macro.
1937  Revised png_squelch_warnings() so it might work.
1938  Updated makefile.sgcc and makefile.solaris; added makefile.solaris-x86.
1939
1940Version 1.2.19beta10 [May 24, 2007]
1941  Resquelched png_squelch_warnings(), use "__attribute__((used))" instead.
1942
1943Version 1.4.0beta1 [April 20, 2006]
1944  Enabled iTXt support (changes png_struct, thus requires so-number change).
1945  Cleaned up PNG_ASSEMBLER_CODE_SUPPORTED vs PNG_MMX_CODE_SUPPORTED
1946  Eliminated PNG_1_0_X and PNG_1_2_X macros.
1947  Removed deprecated functions png_read_init, png_write_init, png_info_init,
1948    png_permit_empty_plte, png_set_gray_1_2_4_to_8, png_check_sig, and
1949    removed the deprecated macro PNG_MAX_UINT.
1950  Moved "PNG_INTERNAL" parts of png.h and pngconf.h into pngintrn.h
1951  Removed many WIN32_WCE #ifdefs (Cosmin).
1952  Reduced dependency on C-runtime library when on Windows (Simon-Pierre)
1953  Replaced sprintf() with png_sprintf() (Simon-Pierre)
1954
1955Version 1.4.0beta2 [April 20, 2006]
1956  Revised makefiles and configure to avoid making links to libpng.so.*
1957  Moved some leftover MMX-related defines from pngconf.h to pngintrn.h
1958  Updated scripts/pngos2.def, pngw32.def, and projects/wince/png32ce.def
1959
1960Version 1.4.0beta3 [May 10, 2006]
1961  Updated scripts/pngw32.def to comment out MMX functions.
1962  Added PNG_NO_GET_INT_32 and PNG_NO_SAVE_INT_32 macros.
1963  Scripts/libpng.pc.in contained "configure" style version info and would
1964    not work with makefiles.
1965  Revised pngconf.h and added pngconf.h.in, so makefiles and configure can
1966    pass defines to libpng and applications.
1967
1968Version 1.4.0beta4 [May 11, 2006]
1969  Revised configure.ac, Makefile.am, and many of the makefiles to write
1970    their defines in pngconf.h.
1971
1972Version 1.4.0beta5 [May 15, 2006]
1973  Added a missing semicolon in Makefile.am and Makefile.in
1974  Deleted extraneous square brackets from configure.ac
1975
1976Version 1.4.0beta6 [June 2, 2006]
1977  Increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
1978    buffer overflow.
1979  Changed sonum from 0 to 1.
1980  Removed unused prototype for png_check_sig() from png.h
1981
1982Version 1.4.0beta7 [June 16, 2006]
1983  Exported png_write_sig (Cosmin).
1984  Optimized buffer in png_handle_cHRM() (Cosmin).
1985  Set pHYs = 2835 x 2835 pixels per meter, and added
1986    sCAL = 0.352778e-3 x 0.352778e-3 meters, in pngtest.png (Cosmin).
1987  Added png_set_benign_errors(), png_benign_error(), png_chunk_benign_error().
1988  Added typedef for png_int_32 and png_uint_32 on 64-bit systems.
1989  Added "(unsigned long)" typecast on png_uint_32 variables in printf lists.
1990
1991Version 1.4.0beta8 [June 22, 2006]
1992  Added demonstration of user chunk support in pngtest.c, to support the
1993    public sTER chunk and a private vpAg chunk.
1994
1995Version 1.4.0beta9 [July 3, 2006]
1996  Removed ordinals from scripts/pngw32.def and removed png_info_int and
1997    png_set_gray_1_2_4_to_8 entries.
1998  Inline call of png_get_uint_32() in png_get_uint_31().
1999  Use png_get_uint_31() to get vpAg width and height in pngtest.c
2000  Removed WINCE and Netware projects.
2001  Removed standalone Y2KINFO file.
2002
2003Version 1.4.0beta10 [July 12, 2006]
2004  Eliminated automatic copy of pngconf.h to pngconf.h.in from configure and
2005    some makefiles, because it was not working reliably.  Instead, distribute
2006    pngconf.h.in along with pngconf.h and cause configure and some of the
2007    makefiles to update pngconf.h from pngconf.h.in.
2008  Added pngconf.h to DEPENDENCIES in Makefile.am
2009
2010Version 1.4.0beta11 [August 19, 2006]
2011  Removed AC_FUNC_MALLOC from configure.ac.
2012  Added a warning when writing iCCP profile with mismatched profile length.
2013  Patched pnggccrd.c to assemble on x86_64 platforms.
2014  Moved chunk header reading into a separate function png_read_chunk_header()
2015    in pngrutil.c.  The chunk header (len+sig) is now serialized in a single
2016    operation (Cosmin).
2017  Implemented support for I/O states. Added png_ptr member io_state, and
2018    functions png_get_io_chunk_name() and png_get_io_state() in pngget.c
2019    (Cosmin).
2020  Added png_get_io_chunk_name and png_get_io_state to scripts/*.def (Cosmin).
2021  Renamed scripts/pngw32.* to scripts/pngwin.* (Cosmin).
2022  Removed the include directories and libraries from CFLAGS and LDFLAGS
2023    in scripts/makefile.gcc (Cosmin).
2024  Used png_save_uint_32() to set vpAg width and height in pngtest.c (Cosmin).
2025  Cast to proper type when getting/setting vpAg units in pngtest.c (Cosmin).
2026  Added pngintrn.h to the Visual C++ projects (Cosmin).
2027  Removed scripts/list (Cosmin).
2028  Updated copyright year in scripts/pngwin.def (Cosmin).
2029  Removed PNG_TYPECAST_NULL and used standard NULL consistently (Cosmin).
2030  Disallowed the user to redefine png_size_t, and enforced a consistent use
2031    of png_size_t across libpng (Cosmin).
2032  Changed the type of png_ptr->rowbytes, PNG_ROWBYTES() and friends
2033    to png_size_t (Cosmin).
2034  Removed png_convert_size() and replaced png_sizeof with sizeof (Cosmin).
2035  Removed some unnecessary type casts (Cosmin).
2036  Changed prototype of png_get_compression_buffer_size() and
2037    png_set_compression_buffer_size() to work with png_size_t instead of
2038    png_uint_32 (Cosmin).
2039  Removed png_memcpy_check() and png_memset_check() (Cosmin).
2040  Fixed a typo (png_byte --> png_bytep) in libpng.3 and libpng.txt (Cosmin).
2041  Clarified that png_zalloc() does not clear the allocated memory,
2042    and png_zalloc() and png_zfree() cannot be PNGAPI (Cosmin).
2043  Renamed png_mem_size_t to png_alloc_size_t, fixed its definition in
2044    pngconf.h, and used it in all memory allocation functions (Cosmin).
2045  Renamed pngintrn.h to pngpriv.h, added a comment at the top of the file
2046    mentioning that the symbols declared in that file are private, and
2047    updated the scripts and the Visual C++ projects accordingly (Cosmin).
2048  Removed circular references between pngconf.h and pngconf.h.in in
2049    scripts/makefile.vc*win32 (Cosmin).
2050  Removing trailing '.' from the warning and error messages (Cosmin).
2051  Added pngdefs.h that is built by makefile or configure, instead of
2052    pngconf.h.in (Glenn).
2053  Detect and fix attempt to write wrong iCCP profile length.
2054
2055Version 1.4.0beta12 [October 19, 2006]
2056  Changed "logical" to "bitwise" in the documentation.
2057  Work around Intel-Mac compiler bug by setting PNG_NO_MMX_CODE in pngconf.h
2058  Add a typecast to stifle compiler warning in pngrutil.c
2059
2060Version 1.4.0beta13 [November 10, 2006]
2061  Fix potential buffer overflow in sPLT chunk handler.
2062  Fix Makefile.am to not try to link to noexistent files.
2063
2064Version 1.4.0beta14 [November 15, 2006]
2065  Check all exported functions for NULL png_ptr.
2066
2067Version 1.4.0beta15 [November 17, 2006]
2068  Relocated two misplaced tests for NULL png_ptr.
2069  Built Makefile.in with automake-1.9.6 instead of 1.9.2.
2070  Build configure with autoconf-2.60 instead of 2.59
2071  Add "install: all" in Makefile.am so "configure; make install" will work.
2072
2073Version 1.4.0beta16 [November 17, 2006]
2074  Added a typecast in png_zalloc().
2075
2076Version 1.4.0beta17 [December 4, 2006]
2077  Changed "new_key[79] = '\0';" to "(*new_key)[79] = '\0';" in pngwutil.c
2078  Add "png_bytep" typecast to profile while calculating length in pngwutil.c
2079
2080Version 1.4.0beta18 [December 7, 2006]
2081  Added scripts/CMakeLists.txt
2082
2083Version 1.4.0beta19 [May 16, 2007]
2084  Revised scripts/CMakeLists.txt
2085  Rebuilt configure and Makefile.in with newer tools.
2086  Added conditional #undef jmpbuf in pngtest.c to undo #define in AIX headers.
2087  Added scripts/makefile.nommx
2088
2089Version 1.4.0beta20 [July 9, 2008]
2090  Moved several PNG_HAVE_* macros from pngpriv.h to png.h because applications
2091    calling set_unknown_chunk_location() need them.
2092  Moved several macro definitions from pngpriv.h to pngconf.h
2093  Merge with changes to the 1.2.X branch, as of 1.2.30beta04.
2094  Deleted all use of the MMX assembler code and Intel-licensed optimizations.
2095  Revised makefile.mingw
2096
2097Version 1.4.0beta21 [July 21, 2008]
2098  Moved local array "chunkdata" from pngrutil.c to the png_struct, so
2099    it will be freed by png_read_destroy() in case of a read error (Kurt
2100    Christensen).
2101
2102Version 1.4.0beta22 [July 21, 2008]
2103  Change "purpose" and "buffer" to png_ptr->chunkdata to avoid memory leaking.
2104
2105Version 1.4.0beta23 [July 22, 2008]
2106  Change "chunkdata = NULL" to "png_ptr->chunkdata = NULL" several places in
2107    png_decompress_chunk().
2108
2109Version 1.4.0beta24 [July 25, 2008]
2110  Change all remaining "chunkdata" to "png_ptr->chunkdata" in
2111    png_decompress_chunk(), and remove "chunkdata" from parameter list.
2112  Put a call to png_check_chunk_name() in png_read_chunk_header().
2113  Revised png_check_chunk_name() to reject a name with a lowercase 3rd byte.
2114  Removed two calls to png_check_chunk_name() occurring later in the process.
2115  Define PNG_NO_ERROR_NUMBERS by default in pngconf.h
2116
2117Version 1.4.0beta25 [July 30, 2008]
2118  Added a call to png_check_chunk_name() in pngpread.c
2119  Reverted png_check_chunk_name() to accept a name with a lowercase 3rd byte.
2120  Added png_push_have_buffer() function to pngpread.c
2121  Eliminated PNG_BIG_ENDIAN_SUPPORTED and associated png_get_* macros.
2122  Made inline expansion of png_get_*() optional with PNG_USE_READ_MACROS.
2123  Eliminated all PNG_USELESS_TESTS and PNG_CORRECT_PALETTE_SUPPORTED code.
2124  Synced contrib directory and configure files with libpng-1.2.30beta06.
2125  Eliminated no-longer-used pngdefs.h (but it's still built in the makefiles)
2126  Relocated a misplaced "#endif /* PNG_NO_WRITE_FILTER */" in pngwutil.c
2127
2128Version 1.4.0beta26 [August 4, 2008]
2129  Removed png_push_have_buffer() function in pngpread.c.  It increased the
2130    compiled library size slightly.
2131  Changed "-Wall" to "-W -Wall" in the CFLAGS in all makefiles (Cosmin Truta)
2132  Declared png_ptr "volatile" in pngread.c and pngwrite.c to avoid warnings.
2133  Updated contrib/visupng/cexcept.h to version 2.0.1
2134  Added PNG_LITERAL_CHARACTER macros for #, [, and ].
2135
2136Version 1.4.0beta27 [August 5, 2008]
2137  Revised usage of PNG_LITERAL_SHARP in pngerror.c.
2138  Moved newline character from individual png_debug messages into the
2139    png_debug macros.
2140  Allow user to #define their own png_debug, png_debug1, and png_debug2.
2141
2142Version 1.4.0beta28 [August 5, 2008]
2143  Revised usage of PNG_LITERAL_SHARP in pngerror.c.
2144  Added PNG_STRING_NEWLINE macro
2145
2146Version 1.4.0beta29 [August 9, 2008]
2147  Revised usage of PNG_STRING_NEWLINE to work on non-ISO compilers.
2148  Added PNG_STRING_COPYRIGHT macro.
2149  Added non-ISO versions of png_debug macros.
2150
2151Version 1.4.0beta30 [August 14, 2008]
2152  Added premultiplied alpha feature (Volker Wiendl).
2153
2154Version 1.4.0beta31 [August 18, 2008]
2155  Moved png_set_premultiply_alpha from pngtrans.c to pngrtran.c
2156  Removed extra crc check at the end of png_handle_cHRM().  Bug introduced
2157    in libpng-1.4.0beta20.
2158
2159Version 1.4.0beta32 [August 19, 2008]
2160  Added PNG_WRITE_FLUSH_SUPPORTED block around new png_flush() call.
2161  Revised PNG_NO_STDIO version of png_write_flush()
2162
2163Version 1.4.0beta33 [August 20, 2008]
2164  Added png_get|set_chunk_cache_max() to limit the total number of sPLT,
2165    text, and unknown chunks that can be stored.
2166
2167Version 1.4.0beta34 [September 6, 2008]
2168  Shortened tIME_string to 29 bytes in pngtest.c
2169  Fixed off-by-one error introduced in png_push_read_zTXt() function in
2170    libpng-1.2.30beta04/pngpread.c (Harald van Dijk)
2171
2172Version 1.4.0beta35 [October 6, 2008]
2173  Changed "trans_values" to "trans_color".
2174  Changed so-number from 0 to 14.  Some OS do not like 0.
2175  Revised makefile.darwin to fix shared library numbering.
2176  Change png_set_gray_1_2_4_to_8() to png_set_expand_gray_1_2_4_to_8()
2177    in example.c (debian bug report)
2178
2179Version 1.4.0beta36 [October 25, 2008]
2180  Sync with tEXt vulnerability fix in libpng-1.2.33rc02.
2181
2182Version 1.4.0beta37 [November 13, 2008]
2183  Added png_check_cHRM in png.c and moved checking from pngget.c, pngrutil.c,
2184    and pngwrite.c
2185
2186Version 1.4.0beta38 [November 22, 2008]
2187  Added check for zero-area RGB cHRM triangle in png_check_cHRM() and
2188    png_check_cHRM_fixed().
2189
2190Version 1.4.0beta39 [November 23, 2008]
2191  Revised png_warning() to write its message on standard output by default
2192    when warning_fn is NULL.
2193
2194Version 1.4.0beta40 [November 24, 2008]
2195  Eliminated png_check_cHRM().  Instead, always use png_check_cHRM_fixed().
2196  In png_check_cHRM_fixed(), ensure white_y is > 0, and removed redundant
2197    check for all-zero coordinates that is detected by the triangle check.
2198
2199Version 1.4.0beta41 [November 26, 2008]
2200  Fixed string vs pointer-to-string error in png_check_keyword().
2201  Rearranged test expressions in png_check_cHRM_fixed() to avoid internal
2202    overflows.
2203  Added PNG_NO_CHECK_cHRM conditional.
2204
2205Version 1.4.0beta42, 43 [December 1, 2008]
2206  Merge png_debug with version 1.2.34beta04.
2207
2208Version 1.4.0beta44 [December 6, 2008]
2209  Removed redundant check for key==NULL before calling png_check_keyword()
2210    to ensure that new_key gets initialized and removed extra warning
2211    (Merge with version 1.2.34beta05 -- Arvan Pritchard).
2212
2213Version 1.4.0beta45 [December 9, 2008]
2214  In png_write_png(), respect the placement of the filler bytes in an earlier
2215    call to png_set_filler() (Jim Barry).
2216
2217Version 1.4.0beta46 [December 10, 2008]
2218  Undid previous change and added PNG_TRANSFORM_STRIP_FILLER_BEFORE and
2219    PNG_TRANSFORM_STRIP_FILLER_AFTER conditionals and deprecated
2220    PNG_TRANSFORM_STRIP_FILLER (Jim Barry).
2221
2222Version 1.4.0beta47 [December 15, 2008]
2223  Support for dithering was disabled by default, because it has never
2224    been well tested and doesn't work very well.  The code has not
2225    been removed, however, and can be enabled by building libpng with
2226    PNG_READ_DITHER_SUPPORTED defined.
2227
2228Version 1.4.0beta48 [February 14, 2009]
2229  Added new exported function png_calloc().
2230  Combined several instances of png_malloc(); png_memset() into png_calloc().
2231  Removed prototype for png_freeptr() that was added in libpng-1.4.0beta24
2232    but was never defined.
2233
2234Version 1.4.0beta49 [February 28, 2009]
2235  Added png_fileno() macro to pngconf.h, used in pngwio.c
2236  Corrected order of #ifdef's in png_debug definition in png.h
2237  Fixed bug introduced in libpng-1.4.0beta48 with the memset arguments
2238    for pcal_params.
2239  Fixed order of #ifdef directives in the png_debug defines in png.h
2240    (bug introduced in libpng-1.2.34/1.4.0beta29).
2241  Revised comments in png_set_read_fn() and png_set_write_fn().
2242
2243Version 1.4.0beta50 [March 18, 2009]
2244  Use png_calloc() instead of png_malloc() to allocate big_row_buf when
2245    reading an interlaced file, to avoid a possible UMR.
2246  Undid revision of PNG_NO_STDIO version of png_write_flush().  Users
2247    having trouble with fflush() can build with PNG_NO_WRITE_FLUSH defined
2248    or supply their own flush_fn() replacement.
2249  Revised libpng*.txt and png.h documentation about use of png_write_flush()
2250    and png_set_write_fn().
2251  Removed fflush() from pngtest.c.
2252  Added "#define PNG_NO_WRITE_FLUSH" to contrib/pngminim/encoder/pngusr.h
2253
2254Version 1.4.0beta51 [March 21, 2009]
2255  Removed new png_fileno() macro from pngconf.h .
2256
2257Version 1.4.0beta52 [March 27, 2009]
2258  Relocated png_do_chop() ahead of building gamma tables in pngrtran.c
2259    This avoids building 16-bit gamma tables unnecessarily.
2260  Removed fflush() from pngtest.c.
2261  Added "#define PNG_NO_WRITE_FLUSH" to contrib/pngminim/encoder/pngusr.h
2262  Added a section on differences between 1.0.x and 1.2.x to libpng.3/libpng.txt
2263
2264Version 1.4.0beta53 [April 1, 2009]
2265  Removed some remaining MMX macros from pngpriv.h
2266  Fixed potential memory leak of "new_name" in png_write_iCCP() (Ralph Giles)
2267
2268Version 1.4.0beta54 [April 13, 2009]
2269  Added "ifndef PNG_SKIP_SETJMP_CHECK" block in pngconf.h to allow
2270    application code writers to bypass the check for multiple inclusion
2271    of setjmp.h when they know that it is safe to ignore the situation.
2272  Eliminated internal use of setjmp() in pngread.c and pngwrite.c
2273  Reordered ancillary chunks in pngtest.png to be the same as what
2274    pngtest now produces, and made some cosmetic changes to pngtest output.
2275  Eliminated deprecated png_read_init_3() and png_write_init_3() functions.
2276
2277Version 1.4.0beta55 [April 15, 2009]
2278  Simplified error handling in pngread.c and pngwrite.c by putting
2279    the new png_read_cleanup() and png_write_cleanup() functions inline.
2280
2281Version 1.4.0beta56 [April 25, 2009]
2282  Renamed "user_chunk_data" to "my_user_chunk_data" in pngtest.c to suppress
2283    "shadowed declaration" warning from gcc-4.3.3.
2284  Renamed "gamma" to "png_gamma" in pngset.c to avoid "shadowed declaration"
2285    warning about a global "gamma" variable in math.h on some platforms.
2286
2287Version 1.4.0beta57 [May 2, 2009]
2288  Removed prototype for png_freeptr() that was added in libpng-1.4.0beta24
2289    but was never defined (again).
2290  Rebuilt configure scripts with autoconf-2.63 instead of 2.62
2291  Removed pngprefs.h and MMX from makefiles
2292
2293Version 1.4.0beta58 [May 14, 2009]
2294  Changed pngw32.def to pngwin.def in makefile.mingw (typo was introduced
2295    in beta57).
2296  Clarified usage of sig_bit versus sig_bit_p in example.c (Vincent Torri)
2297
2298Version 1.4.0beta59 [May 15, 2009]
2299  Reformated sources in libpng style (3-space intentation, comment format)
2300  Fixed typo in libpng docs (PNG_FILTER_AVE should be PNG_FILTER_AVG)
2301  Added sections about the git repository and our coding style to the
2302    documentation
2303  Relocated misplaced #endif in pngwrite.c, sCAL chunk handler.
2304
2305Version 1.4.0beta60 [May 19, 2009]
2306  Conditionally compile png_read_finish_row() which is not used by
2307    progressive readers.
2308  Added contrib/pngminim/preader to demonstrate building minimal progressive
2309    decoder, based on contrib/gregbook with embedded libpng and zlib.
2310
2311Version 1.4.0beta61 [May 20, 2009]
2312  In contrib/pngminim/*, renamed "makefile.std" to "makefile", since there
2313    is only one makefile in those directories, and revised the README files
2314    accordingly.
2315  More reformatting of comments, mostly to capitalize sentences.
2316
2317Version 1.4.0beta62 [June 2, 2009]
2318  Added "#define PNG_NO_WRITE_SWAP" to contrib/pngminim/encoder/pngusr.h
2319    and "define PNG_NO_READ_SWAP" to decoder/pngusr.h and preader/pngusr.h
2320  Reformatted several remaining "else statement" into two lines.
2321  Added a section to the libpng documentation about using png_get_io_ptr()
2322    in configure scripts to detect the presence of libpng.
2323
2324Version 1.4.0beta63 [June 15, 2009]
2325  Revised libpng*.txt and libpng.3 to mention calling png_set_IHDR()
2326    multiple times and to specify the sample order in the tRNS chunk,
2327    because the ISO PNG specification has a typo in the tRNS table.
2328  Changed several PNG_UNKNOWN_CHUNK_SUPPORTED to
2329    PNG_HANDLE_AS_UNKNOWN_SUPPORTED, to make the png_set_keep mechanism
2330    available for ignoring known chunks even when not saving unknown chunks.
2331  Adopted preference for consistent use of "#ifdef" and "#ifndef" versus
2332    "#if defined()" and "if !defined()" where possible.
2333
2334Version 1.4.0beta64 [June 24, 2009]
2335  Eliminated PNG_LEGACY_SUPPORTED code.
2336  Moved the various unknown chunk macro definitions outside of the
2337    PNG_READ|WRITE_ANCILLARY_CHUNK_SUPPORTED blocks.
2338
2339Version 1.4.0beta65 [June 26, 2009]
2340  Added a reference to the libpng license in each file.
2341
2342Version 1.4.0beta66 [June 27, 2009]
2343  Refer to the libpng license instead of the libpng license in each file.
2344
2345Version 1.4.0beta67 [July 6, 2009]
2346  Relocated INVERT_ALPHA within png_read_png() and png_write_png().
2347  Added high-level API transform PNG_TRANSFORM_GRAY_TO_RGB.
2348  Added an "xcode" project to the projects directory (Alam Arias).
2349
2350Version 1.4.0beta68 [July 19, 2009]
2351  Avoid some tests in filter selection in pngwutil.c
2352
2353Version 1.4.0beta69 [July 25, 2009]
2354  Simplified the new filter-selection test.  This runs faster in the
2355    common "PNG_ALL_FILTERS" and PNG_FILTER_NONE cases.
2356  Removed extraneous declaration from the new call to png_read_gray_to_rgb()
2357    (bug introduced in libpng-1.4.0beta67).
2358  Fixed up xcode project (Alam Arias)
2359  Added a prototype for png_64bit_product() in png.c
2360
2361Version 1.4.0beta70 [July 27, 2009]
2362  Avoid a possible NULL dereference in debug build, in png_set_text_2().
2363    (bug introduced in libpng-0.95, discovered by Evan Rouault)
2364
2365Version 1.4.0beta71 [July 29, 2009]
2366  Rebuilt configure scripts with autoconf-2.64.
2367
2368Version 1.4.0beta72 [August 1, 2009]
2369  Replaced *.tar.lzma with *.tar.xz in distribution.  Get the xz codec
2370    from <http://tukaani.org/xz>.
2371
2372Version 1.4.0beta73 [August 1, 2009]
2373  Reject attempt to write iCCP chunk with negative embedded profile length
2374    (JD Chen) (CVE-2009-5063).
2375
2376Version 1.4.0beta74 [August 8, 2009]
2377  Changed png_ptr and info_ptr member "trans" to "trans_alpha".
2378
2379Version 1.4.0beta75 [August 21, 2009]
2380  Removed an extra png_debug() recently added to png_write_find_filter().
2381  Fixed incorrect #ifdef in pngset.c regarding unknown chunk support.
2382
2383Version 1.4.0beta76 [August 22, 2009]
2384  Moved an incorrectly located test in png_read_row() in pngread.c
2385
2386Version 1.4.0beta77 [August 27, 2009]
2387  Removed lpXYZ.tar.bz2 (with CRLF), KNOWNBUG, libpng-x.y.z-KNOWNBUG.txt,
2388    and the "noconfig" files from the distribution.
2389  Moved CMakeLists.txt from scripts into the main libpng directory.
2390  Various bugfixes and improvements to CMakeLists.txt (Philip Lowman)
2391
2392Version 1.4.0beta78 [August 31, 2009]
2393  Converted all PNG_NO_* tests to PNG_*_SUPPORTED everywhere except pngconf.h
2394  Eliminated PNG_NO_FREE_ME and PNG_FREE_ME_SUPPORTED macros.
2395  Use png_malloc plus a loop instead of png_calloc() to initialize
2396    row_pointers in png_read_png().
2397
2398Version 1.4.0beta79 [September 1, 2009]
2399  Eliminated PNG_GLOBAL_ARRAYS and PNG_LOCAL_ARRAYS; always use local arrays.
2400  Eliminated PNG_CALLOC_SUPPORTED macro and always provide png_calloc().
2401
2402Version 1.4.0beta80 [September 17, 2009]
2403  Removed scripts/libpng.icc
2404  Changed typecast of filler from png_byte to png_uint_16 in png_set_filler().
2405    (Dennis Gustafsson)
2406  Fixed typo introduced in beta78 in pngtest.c ("#if def " should be "#ifdef ")
2407
2408Version 1.4.0beta81 [September 23, 2009]
2409  Eliminated unused PNG_FLAG_FREE_* defines from pngpriv.h
2410  Expanded TAB characters in pngrtran.c
2411  Removed PNG_CONST from all "PNG_CONST PNG_CHNK" declarations to avoid
2412    compiler complaints about doubly declaring things "const".
2413  Changed all "#if [!]defined(X)" to "if[n]def X" where possible.
2414  Eliminated unused png_ptr->row_buf_size
2415
2416Version 1.4.0beta82 [September 25, 2009]
2417  Moved redundant IHDR checking into new png_check_IHDR() in png.c
2418    and report all errors found in the IHDR data.
2419  Eliminated useless call to png_check_cHRM() from pngset.c
2420
2421Version 1.4.0beta83 [September 25, 2009]
2422  Revised png_check_IHDR() to eliminate bogus complaint about filter_type.
2423
2424Version 1.4.0beta84 [September 30, 2009]
2425  Fixed some inconsistent indentation in pngconf.h
2426  Revised png_check_IHDR() to add a test for width variable less than 32-bit.
2427
2428Version 1.4.0beta85 [October 1, 2009]
2429  Revised png_check_IHDR() again, to check info_ptr members instead of
2430    the contents of the returned parameters.
2431
2432Version 1.4.0beta86 [October 9, 2009]
2433  Updated the "xcode" project (Alam Arias).
2434  Eliminated a shadowed declaration of "pp" in png_handle_sPLT().
2435
2436Version 1.4.0rc01 [October 19, 2009]
2437  Trivial cosmetic changes.
2438
2439Version 1.4.0beta87 [October 30, 2009]
2440  Moved version 1.4.0 back into beta.
2441
2442Version 1.4.0beta88 [October 30, 2009]
2443  Revised libpng*.txt section about differences between 1.2.x and 1.4.0
2444    because most of the new features have now been ported back to 1.2.41
2445
2446Version 1.4.0beta89 [November 1, 2009]
2447  More bugfixes and improvements to CMakeLists.txt (Philip Lowman)
2448  Removed a harmless extra png_set_invert_alpha() from pngwrite.c
2449  Apply png_user_chunk_cache_max within png_decompress_chunk().
2450  Merged libpng-1.2.41.txt with libpng-1.4.0.txt where appropriate.
2451
2452Version 1.4.0beta90 [November 2, 2009]
2453  Removed all remaining WIN32_WCE #ifdefs except those involving the
2454    time.h "tm" structure
2455
2456Version 1.4.0beta91 [November 3, 2009]
2457  Updated scripts/pngw32.def and projects/wince/png32ce.def
2458  Copied projects/wince/png32ce.def to the scripts directory.
2459  Added scripts/makefile.wce
2460  Patched ltmain.sh for wince support.
2461  Added PNG_CONVERT_tIME_SUPPORTED macro.
2462
2463Version 1.4.0beta92 [November 4, 2009]
2464  Make inclusion of time.h in pngconf.h depend on PNG_CONVERT_tIME_SUPPORTED
2465  Make #define PNG_CONVERT_tIME_SUPPORTED depend on PNG_WRITE_tIME_SUPPORTED
2466  Revised libpng*.txt to describe differences from 1.2.40 to 1.4.0 (instead
2467    of differences from 1.2.41 to 1.4.0)
2468
2469Version 1.4.0beta93 [November 7, 2009]
2470  Added PNG_DEPSTRUCT, PNG_DEPRECATED, PNG_USE_RESULT, PNG_NORETURN, and
2471    PNG_ALLOCATED macros to detect deprecated direct access to the
2472    png_struct or info_struct members and other deprecated usage in
2473    applications (John Bowler).
2474  Updated scripts/makefile* to add "-DPNG_CONFIGURE_LIBPNG" to CFLAGS,
2475    to prevent warnings about direct access to png structs by libpng
2476    functions while building libpng.  They need to be tested, especially
2477    those using compilers other than gcc.
2478  Updated projects/visualc6 and visualc71 with "/d PNG_CONFIGURE_LIBPNG".
2479    They should work but still need to be updated to remove
2480    references to pnggccrd.c or pngvcrd.c and ASM building.
2481  Added README.txt to the beos, cbuilder5, netware, and xcode projects warning
2482    that they need to be updated, to remove references to pnggccrd.c and
2483    pngvcrd.c and to depend on pngpriv.h
2484  Removed three direct references to read_info_ptr members in pngtest.c
2485    that were detected by the new PNG_DEPSTRUCT macro.
2486  Moved the png_debug macro definitions and the png_read_destroy(),
2487    png_write_destroy() and png_far_to_near() prototypes from png.h
2488    to pngpriv.h (John Bowler)
2489  Moved the synopsis lines for png_read_destroy(), png_write_destroy()
2490    png_debug(), png_debug1(), and png_debug2() from libpng.3 to libpngpf.3.
2491
2492Version 1.4.0beta94 [November 9, 2009]
2493  Removed the obsolete, unused pnggccrd.c and pngvcrd.c files.
2494  Updated CMakeLists.txt to add "-DPNG_CONFIGURE_LIBPNG" to the definitions.
2495  Removed dependency of pngtest.o on pngpriv.h in the makefiles.
2496  Only #define PNG_DEPSTRUCT, etc. in pngconf.h if not already defined.
2497
2498Version 1.4.0beta95 [November 10, 2009]
2499  Changed png_check_sig() to !png_sig_cmp() in contrib programs.
2500  Added -DPNG_CONFIGURE_LIBPNG to contrib/pngminm/*/makefile
2501  Changed png_check_sig() to !png_sig_cmp() in contrib programs.
2502  Corrected the png_get_IHDR() call in contrib/gregbook/readpng2.c
2503  Changed pngminim/*/gather.sh to stop trying to remove pnggccrd.c and pngvcrd.c
2504  Added dependency on pngpriv.h in contrib/pngminim/*/makefile
2505
2506Version 1.4.0beta96 [November 12, 2009]
2507  Renamed scripts/makefile.wce to scripts/makefile.cegcc
2508  Revised Makefile.am to use libpng.sys while building libpng.so
2509    so that only PNG_EXPORT functions are exported.
2510  Removed the deprecated png_check_sig() function/macro.
2511  Removed recently removed function names from scripts/*.def
2512  Revised pngtest.png to put chunks in the same order written by pngtest
2513    (evidently the same change made in libpng-1.0beta54 was lost).
2514  Added PNG_PRIVATE macro definition in pngconf.h for possible future use.
2515
2516Version 1.4.0beta97 [November 13, 2009]
2517  Restored pngtest.png to the libpng-1.4.0beta7 version.
2518  Removed projects/beos and netware.txt; no one seems to be supporting them.
2519  Revised Makefile.in
2520
2521Version 1.4.0beta98 [November 13, 2009]
2522  Added the "xcode" project to zip distributions,
2523  Fixed a typo in scripts/pngwin.def introduced in beta97.
2524
2525Version 1.4.0beta99 [November 14, 2009]
2526  Moved libpng-config.in and libpng.pc-configure.in out of the scripts
2527    directory, to libpng-config.in and libpng-pc.in, respectively, and
2528    modified Makefile.am and configure.ac accordingly.  Now "configure"
2529    needs nothing from the "scripts" directory.
2530  Avoid redefining PNG_CONST in pngconf.h
2531
2532Version 1.4.0beta100 [November 14, 2009]
2533  Removed ASM builds from projects/visualc6 and projects/visualc71
2534  Removed scripts/makefile.nommx and makefile.vcawin32
2535  Revised CMakeLists.txt to account for new location of libpng-config.in
2536    and libpng-pc.in
2537  Updated INSTALL to reflect removal and relocation of files.
2538
2539Version 1.4.0beta101 [November 14, 2009]
2540  Restored the binary files (*.jpg, *.png, some project files) that were
2541    accidentally deleted from the zip and 7z distributions when the xcode
2542    project was added.
2543
2544Version 1.4.0beta102 [November 18, 2009]
2545  Added libpng-config.in and libpng-pc.in to the zip and 7z distributions.
2546  Fixed a typo in projects/visualc6/pngtest.dsp, introduced in beta100.
2547  Moved descriptions of makefiles and other scripts out of INSTALL into
2548    scripts/README.txt
2549  Updated the copyright year in scripts/pngwin.rc from 2006 to 2009.
2550
2551Version 1.4.0beta103 [November 21, 2009]
2552  Removed obsolete comments about ASM from projects/visualc71/README_zlib.txt
2553  Align row_buf on 16-byte boundary in memory.
2554  Restored the PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED guard around the call
2555    to png_flush() after png_write_IEND().  See 1.4.0beta32, 1.4.0beta50
2556    changes above and 1.2.30, 1.2.30rc01 and rc03 in 1.2.41 CHANGES.  Someone
2557    needs this feature.
2558  Make the 'png_jmpbuf' macro expand to a call that records the correct
2559    longjmp function as well as returning a pointer to the setjmp
2560    jmp_buf buffer, and marked direct access to jmpbuf 'deprecated'.
2561    (John Bowler)
2562
2563Version 1.4.0beta104 [November 22, 2009]
2564  Removed png_longjmp_ptr from scripts/*.def and libpng.3
2565  Rebuilt configure scripts with autoconf-2.65
2566
2567Version 1.4.0beta105 [November 25, 2009]
2568  Use fast integer PNG_DIVIDE_BY_255() or PNG_DIVIDE_BY_65535()
2569    to accomplish alpha premultiplication when
2570    PNG_READ_COMPOSITE_NODIV_SUPPORTED is defined.
2571  Changed "/255" to "/255.0" in background calculations to make it clear
2572    that the 255 is used as a double.
2573
2574Version 1.4.0beta106 [November 27, 2009]
2575  Removed premultiplied alpha feature.
2576
2577Version 1.4.0beta107 [December 4, 2009]
2578  Updated README
2579  Added "#define PNG_NO_PEDANTIC_WARNINGS" in the libpng source files.
2580  Removed "-DPNG_CONFIGURE_LIBPNG" from the makefiles and projects.
2581  Revised scripts/makefile.netbsd, makefile.openbsd, and makefile.sco
2582    to put png.h and pngconf.h in $prefix/include, like the other scripts,
2583    instead of in $prefix/include/libpng.  Also revised makefile.sco
2584    to put them in $prefix/include/libpng15 instead of in
2585    $prefix/include/libpng/libpng15.
2586
2587Version 1.4.0beta108 [December 11, 2009]
2588  Removed leftover "-DPNG_CONFIGURE_LIBPNG" from contrib/pngminim/*/makefile
2589  Relocated png_do_chop() to its original position in pngrtran.c; the
2590    change in version 1.2.41beta08 caused transparency to be handled wrong
2591    in some 16-bit datastreams (Yusaku Sugai).
2592
2593Version 1.4.0beta109 [December 13, 2009]
2594  Added "bit_depth" parameter to the private png_build_gamma_table() function.
2595  Pass bit_depth=8 to png_build_gamma_table() when bit_depth is 16 but the
2596    PNG_16_TO_8 transform has been set, to avoid unnecessary build of 16-bit
2597    tables.
2598
2599Version 1.4.0rc02 [December 20, 2009]
2600  Declared png_cleanup_needed "volatile" in pngread.c and pngwrite.c
2601
2602Version 1.4.0rc03 [December 22, 2009]
2603  Renamed libpng-pc.in back to libpng.pc.in and revised CMakeLists.txt
2604    (revising the change in 1.4.0beta99)
2605
2606Version 1.4.0rc04 [December 25, 2009]
2607  Swapped PNG_UNKNOWN_CHUNKS_SUPPORTED and PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2608    in pngset.c to be consistent with other changes in version 1.2.38.
2609
2610Version 1.4.0rc05 [December 25, 2009]
2611  Changed "libpng-pc.in" to "libpng.pc.in" in configure.ac, configure, and
2612    Makefile.in to be consistent with changes in libpng-1.4.0rc03
2613
2614Version 1.4.0rc06 [December 29, 2009]
2615  Reverted the gamma_table changes from libpng-1.4.0beta109.
2616  Fixed some indentation errors.
2617
2618Version 1.4.0rc07 [January 1, 2010]
2619  Revised libpng*.txt and libpng.3 about 1.2.x->1.4.x differences.
2620  Use png_calloc() instead of png_malloc(); png_memset() in pngrutil.c
2621  Update copyright year to 2010.
2622
2623Version 1.4.0rc08 [January 2, 2010]
2624  Avoid deprecated references to png_ptr-io_ptr and png_ptr->error_ptr
2625    in pngtest.c
2626
2627Version 1.4.0 [January 3, 2010]
2628  No changes.
2629
2630Version 1.4.1beta01 [January 8, 2010]
2631  Updated CMakeLists.txt for consistent indentation and to avoid an
2632    unclosed if-statement warning (Philip Lowman).
2633  Revised Makefile.am and Makefile.in to remove references to Y2KINFO,
2634    KNOWNBUG, and libpng.la (Robert Schwebel).
2635  Revised the makefiles to install the same files and symbolic
2636    links as configure, except for libpng.la and libpng14.la.
2637  Make png_set|get_compression_buffer_size() available even when
2638    PNG_WRITE_SUPPORTED is not enabled.
2639  Revised Makefile.am and Makefile.in to simplify their maintenance.
2640  Revised scripts/makefile.linux to install a link to libpng14.so.14.1
2641
2642Version 1.4.1beta02 [January 9, 2010]
2643  Revised the rest of the makefiles to install a link to libpng14.so.14.1
2644
2645Version 1.4.1beta03 [January 10, 2010]
2646  Removed png_set_premultiply_alpha() from scripts/*.def
2647
2648Version 1.4.1rc01 [January 16, 2010]
2649  No changes.
2650
2651Version 1.4.1beta04 [January 23, 2010]
2652  Revised png_decompress_chunk() to improve speed and memory usage when
2653    decoding large chunks.
2654  Added png_set|get_chunk_malloc_max() functions.
2655
2656Version 1.4.1beta05 [January 26, 2010]
2657  Relocated "int k" declaration in pngtest.c to minimize its scope.
2658
2659Version 1.4.1beta06 [January 28, 2010]
2660  Revised png_decompress_chunk() to use a two-pass method suggested by
2661    John Bowler.
2662
2663Version 1.4.1beta07 [February 6, 2010]
2664  Folded some long lines in the source files.
2665  Added defineable PNG_USER_CHUNK_CACHE_MAX, PNG_USER_CHUNK_MALLOC_MAX,
2666    and a PNG_USER_LIMITS_SUPPORTED flag.
2667  Eliminated use of png_ptr->irowbytes and reused the slot in png_ptr as
2668    png_ptr->png_user_chunk_malloc_max.
2669  Revised png_push_save_buffer() to do fewer but larger png_malloc() calls.
2670
2671Version 1.4.1beta08 [February 6, 2010]
2672  Minor cleanup and updating of dates and copyright year.
2673
2674Version 1.5.0beta01 [February 7, 2010]
2675  Moved declaration of png_struct into private pngstruct.h and png_info
2676    into pnginfo.h
2677
2678Version 1.4.1beta09 and 1.5.0beta02 [February 7, 2010]
2679  Reverted to original png_push_save_buffer() code.
2680
2681Version 1.4.1beta10 and 1.5.0beta03 [February 8, 2010]
2682  Return allocated "old_buffer" in png_push_save_buffer() before
2683    calling png_error(), to avoid a potential memory leak.
2684  Updated configure script to use SO number 15.
2685
2686Version 1.5.0beta04 [February 9, 2010]
2687  Removed malformed "incomplete struct declaration" of png_info from png.h
2688
2689Version 1.5.0beta05 [February 12, 2010]
2690  Removed PNG_DEPSTRUCT markup in pngstruct.h and pnginfo.h, and undid the
2691    linewrapping that it entailed.
2692  Revised comments in pngstruct.h and pnginfo.h and added pointers to
2693    the libpng license.
2694  Changed PNG_INTERNAL to PNG_EXPOSE_INTERNAL_STRUCTURES
2695  Removed the cbuilder5 project, which has not been updated to 1.4.0.
2696
2697Version 1.4.1beta12 and 1.5.0beta06 [February 14, 2010]
2698  Fixed type declaration of png_get_chunk_malloc_max() in pngget.c (Daisuke
2699    Nishikawa)
2700
2701Version 1.5.0beta07 [omitted]
2702
2703Version 1.5.0beta08 [February 19, 2010]
2704  Changed #ifdef PNG_NO_STDIO_SUPPORTED to #ifdef PNG_NO_CONSOLE_IO_SUPPORTED
2705    wherever png_snprintf() is used to construct error and warning messages.
2706  Noted in scripts/makefile.mingw that it expects to be run under MSYS.
2707  Removed obsolete unused MMX-querying support from contrib/gregbook
2708  Added exported png_longjmp() function.
2709  Removed the AIX redefinition of jmpbuf in png.h
2710  Added -D_ALLSOURCE in configure.ac, makefile.aix, and CMakeLists.txt
2711    when building on AIX.
2712
2713Version 1.5.0beta09 [February 19, 2010]
2714  Removed -D_ALLSOURCE from configure.ac, makefile.aix, and CMakeLists.txt.
2715  Changed the name of png_ptr->jmpbuf to png_ptr->png_jmpbuf in pngstruct.h
2716
2717Version 1.5.0beta10 [February 25, 2010]
2718  Removed unused gzio.c from contrib/pngminim gather and makefile scripts
2719  Removed replacement error handlers from contrib/gregbook.  Because of
2720    the new png_longjmp() function they are no longer needed.
2721
2722Version 1.5.0beta11 [March 6, 2010]
2723  Removed checking for already-included setjmp.h from pngconf.h
2724  Fixed inconsistent indentations and made numerous cosmetic changes.
2725  Revised the "SEE ALSO" style of libpng.3, libpngpf.3, and png.5
2726
2727Version 1.5.0beta12 [March 9, 2010]
2728  Moved "#include png.h" inside pngpriv.h and removed "#include png.h" from
2729    the source files, along with "#define PNG_EXPOSE_INTERNAL_STRUCTURES"
2730    and "#define PNG_NO_PEDANTIC_WARNINGS" (John Bowler).
2731  Created new pngdebug.h and moved debug definitions there.
2732
2733Version 1.5.0beta13 [March 10, 2010]
2734  Protect pngstruct.h, pnginfo.h, and pngdebug.h from being included twice.
2735  Revise the "#ifdef" blocks in png_inflate() so it will compile when neither
2736    PNG_USER_CHUNK_MALLOC_MAX nor PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
2737    is defined.
2738  Removed unused png_measure_compressed_chunk() from pngpriv.h and libpngpf.3
2739  Moved the 'config.h' support from pngconf.h to pngpriv.h
2740  Removed PNGAPI from the png_longjmp_ptr typedef.
2741  Eliminated dependence of pngtest.c on the private pngdebug.h file.
2742  Make all png_debug macros into *unterminated* statements or
2743    expressions (i.e. a trailing ';' must always be added) and correct
2744    the format statements in various png_debug messages.
2745
2746Version 1.5.0beta14 [March 14, 2010]
2747  Removed direct access to png_ptr->io_ptr from the Windows code in pngtest.c
2748  Revised Makefile.am to account for recent additions and replacements.
2749  Corrected CE and OS/2 DEF files (scripts/png*def) for symbols removed and
2750    added ordinal numbers to the Windows DEF file and corrected the duplicated
2751    ordinal numbers on CE symbols that are commented out.
2752  Added back in export symbols that can be present in the Windows build but
2753    are disabled by default.
2754  PNG_EXPORT changed to include an 'ordinal' field for DEF file generation.
2755    PNG_CALLBACK added to make callback definitions uniform.  PNGAPI split
2756    into PNGCAPI (base C form), PNGAPI (exports) and PNGCBAPI (callbacks),
2757    and appropriate changes made to all files.  Cygwin builds re-hinged to
2758    allow procedure call standard changes and to remove the need for the DEF
2759    file (fixes build on Cygwin).
2760  Enabled 'attribute' warnings that are relevant to library APIs and callbacks.
2761  Changed rules for generation of the various symbol files and added a new
2762    rule for a DEF file (which is also added to the distribution).
2763  Updated the symbol file generation to stop it adding spurious spaces
2764    to EOL (coming from preprocessor macro expansion).  Added a facility
2765    to join tokens in the output and rewrite *.dfn to use this.
2766  Eliminated scripts/*.def in favor of libpng.def; updated projects/visualc71
2767    and removed scripts/makefile.cygwin.
2768  Made PNG_BUILD_DLL safe: it can be set whenever a DLL is being built.
2769  Removed the include of sys/types.h - apparently unnecessary now on the
2770    platforms on which it happened (all but Mac OS and RISC OS).
2771  Moved the Mac OS test into pngpriv.h (the only place it is used.)
2772
2773Version 1.5.0beta15 [March 17, 2010]
2774  Added symbols.chk target to Makefile.am to validate the symbols in png.h
2775    against the new DEF file scripts/symbols.def.
2776  Changed the default DEF file back to pngwin.def.
2777  Removed makefile.mingw.
2778  Eliminated PNG_NO_EXTERN and PNG_ALL_EXTERN
2779
2780Version 1.5.0beta16 [April 1, 2010]
2781  Make png_text_struct independent of PNG_iTXt_SUPPORTED, so that
2782    fields are initialized in all configurations.  The READ/WRITE
2783    macros (PNG_(READ|WRITE)_iTXt_SUPPORTED) still function as
2784    before to disable code to actually read or write iTXt chunks
2785    and iTXt_SUPPORTED can be used to detect presence of either
2786    read or write support (but it is probably better to check for
2787    the one actually required - read or write.)
2788  Combined multiple png_warning() calls for a single error.
2789  Restored the macro definition of png_check_sig().
2790
2791Version 1.5.0beta17 [April 17, 2010]
2792  Added some "(long)" typecasts to printf calls in png_handle_cHRM().
2793  Documented the fact that png_set_dither() was disabled since libpng-1.4.0.
2794  Reenabled png_set_dither() but renamed it to png_set_quantize() to reflect
2795    more accurately what it actually does.  At the same time, renamed
2796    the PNG_DITHER_[RED,GREEN_BLUE]_BITS macros to
2797    PNG_QUANTIZE_[RED,GREEN,BLUE]_BITS.
2798  Added some "(long)" typecasts to printf calls in png_handle_cHRM().
2799  Freeze build-time only configuration in the build.
2800    In all prior versions of libpng most configuration options
2801    controlled by compiler #defines had to be repeated by the
2802    application code that used libpng.  This patch changes this
2803    so that compilation options that can only be changed at build
2804    time are frozen in the build.  Options that are compiler
2805    dependent (and those that are system dependent) are evaluated
2806    each time - pngconf.h holds these.  Options that can be changed
2807    per-file in the application are in png.h.  Frozen options are
2808    in the new installed header file pnglibconf.h (John Bowler)
2809  Removed the xcode project because it has not been updated to work
2810    with libpng-1.5.0.
2811  Removed the ability to include optional pngusr.h
2812
2813Version 1.5.0beta18 [April 17, 2010]
2814  Restored the ability to include optional pngusr.h
2815  Moved replacements for png_error() and png_warning() from the
2816    contrib/pngminim project to pngerror.c, for use when warnings or
2817    errors are disabled via PNG_NO_WARN or PNG_NO_ERROR_TEXT, to avoid
2818    storing unneeded error/warning text.
2819  Updated contrib/pngminim project to work with the new pnglibconf.h
2820  Added some PNG_NO_* defines to contrib/pngminim/*/pngusr.h to save space.
2821
2822Version 1.5.0beta19 [April 24, 2010]
2823  Added PNG_{READ,WRITE}_INT_FUNCTIONS_SUPPORTED.  This allows the functions
2824    to read and write ints to be disabled independently of PNG_USE_READ_MACROS,
2825    which allows libpng to be built with the functions even though the default
2826    is to use the macros - this allows applications to choose at app build
2827    time whether or not to use macros (previously impossible because the
2828    functions weren't in the default build.)
2829  Changed Windows calling convention back to __cdecl for API functions.
2830    For Windows/x86 platforms only:
2831      __stdcall is no longer needed for Visual Basic, so libpng-1.5.0 uses
2832      __cdecl throughout (both API functions and callbacks) on Windows/x86
2833      platforms.
2834  Replaced visualc6 and visualc71 projects with new vstudio project
2835  Relaxed the overly-restrictive permissions of some files.
2836
2837Version 1.5.0beta20 [April 24, 2010]
2838  Relaxed more overly-restrictive permissions of some files.
2839
2840Version 1.5.0beta21 [April 27, 2010]
2841  Removed some unwanted binary bytes and changed CRLF to NEWLINE in the new
2842    vstudio project files, and some trivial editing of some files in the
2843    scripts directory.
2844  Set PNG_NO_READ_BGR, PNG_NO_IO_STATE, and PNG_NO_TIME_RFC1123 in
2845    contrib/pngminim/decoder/pngusr.h to make a smaller decoder application.
2846
2847Version 1.5.0beta22 [April 28, 2010]
2848  Fixed dependencies of GET_INT_32 - it does not require READ_INT_FUNCTIONS
2849    because it has a macro equivalent.
2850  Improved the options.awk script; added an "everything off" option.
2851  Revised contrib/pngminim to use the "everything off" option in pngusr.dfa.
2852
2853Version 1.5.0beta23 [April 29, 2010]
2854  Corrected PNG_REMOVED macro to take five arguments.
2855    The macro was documented with two arguments (name,ordinal), however
2856    the symbol checking .dfn files assumed five arguments.  The five
2857    argument form seems more useful so it is changed to that.
2858  Corrected PNG_UNKNOWN_CHUNKS_SUPPORTED to PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2859    in gregbook/readpng2.c
2860  Corrected protection of png_get_user_transform_ptr. The API declaration in
2861    png.h is removed if both READ and WRITE USER_TRANSFORM are turned off
2862    but was left defined in pngtrans.c
2863  Added logunsupported=1 to cause pnglibconf.h to document disabled options.
2864    This makes the installed pnglibconf.h more readable but causes no
2865    other change.  The intention is that users of libpng will find it
2866    easier to understand if an API they need is missing.
2867  Include png_reset_zstream() in png.c only when PNG_READ_SUPPORTED is defined.
2868  Removed dummy_inflate.c from contrib/pngminim/encoder
2869  Removed contrib/pngminim/*/gather.sh; gathering is now done in the makefile.
2870
2871Version 1.5.0beta24 [May 7, 2010]
2872  Use bitwise "&" instead of arithmetic mod in pngrutil.c calculation of the
2873    offset of the png_ptr->rowbuf pointer into png_ptr->big_row_buf.
2874  Added more blank lines for readability.
2875
2876Version 1.5.0beta25 [June 18, 2010]
2877  In pngpread.c: png_push_have_row() add check for new_row > height
2878  Removed the now-redundant check for out-of-bounds new_row from example.c
2879
2880Version 1.5.0beta26 [June 18, 2010]
2881  In pngpread.c: png_push_process_row() add check for too many rows.
2882
2883Version 1.5.0beta27 [June 18, 2010]
2884  Removed the check added in beta25 as it is now redundant.
2885
2886Version 1.5.0beta28 [June 20, 2010]
2887  Rewrote png_process_IDAT_data to consistently treat extra data as warnings
2888    and handle end conditions more cleanly.
2889  Removed the new (beta26) check in png_push_process_row().
2890
2891Version 1.5.0beta29 [June 21, 2010]
2892  Revised scripts/options.awk to work on Sunos (but still doesn't work)
2893  Added comment to options.awk and contrib/pngminim/*/makefile to try nawk.
2894
2895Version 1.5.0beta30 [June 22, 2010]
2896  Stop memory leak when reading a malformed sCAL chunk.
2897
2898Version 1.5.0beta31 [June 26, 2010]
2899  Revised pngpread.c patch of beta28 to avoid an endless loop.
2900  Removed some trailing blanks.
2901
2902Version 1.5.0beta32 [June 26, 2010]
2903  Removed leftover scripts/options.patch and scripts/options.rej
2904
2905Version 1.5.0beta33 [July 6, 3010]
2906  Made FIXED and FLOATING options consistent in the APIs they enable and
2907    disable.  Corrected scripts/options.awk to handle both command line
2908    options and options specified in the .dfa files.
2909  Changed char *msg to PNG_CONST char *msg in pngrutil.c
2910  Make png_set_sRGB_gAMA_and_cHRM set values using either the fixed or
2911    floating point APIs, but not both.
2912  Reversed patch to remove error handler when the jmp_buf is stored in the
2913    main program structure, not the png_struct.
2914    The error handler is needed because the default handler in libpng will
2915    always use the jmp_buf in the library control structure; this is never
2916    set.  The gregbook code is a useful example because, even though it
2917    uses setjmp/longjmp, it shows how error handling can be implemented
2918    using control mechanisms not directly supported by libpng.  The
2919    technique will work correctly with mechanisms such as Microsoft
2920    Structure Exceptions or C++ exceptions (compiler willing - note that gcc
2921    does not by default support interworking of C and C++ error handling.)
2922  Reverted changes to call png_longjmp in contrib/gregbook where it is not
2923    appropriate.  If mainprog->jmpbuf is used by setjmp, then png_longjmp
2924    cannot be used.
2925  Changed "extern PNG_EXPORT" to "PNG_EXPORT" in png.h (Jan Nijtmans)
2926  Changed "extern" to "PNG_EXTERN" in pngpriv.h (except for the 'extern "C" {')
2927
2928Version 1.5.0beta34 [July 12, 2010]
2929  Put #ifndef PNG_EXTERN, #endif around the define PNG_EXTERN in pngpriv.h
2930
2931Version 1.5.0beta35 [July 24, 2010]
2932  Removed some newly-added TAB characters.
2933  Added -DNO_PNG_SNPRINTF to CFLAGS in scripts/makefile.dj2
2934  Moved the definition of png_snprintf() outside of the enclosing
2935    #ifdef blocks in pngconf.h
2936
2937Version 1.5.0beta36 [July 29, 2010]
2938  Patches by John Bowler:
2939  Fixed point APIs are now supported throughout (no missing APIs).
2940  Internal fixed point arithmetic support exists for all internal floating
2941    point operations.
2942  sCAL validates the floating point strings it is passed.
2943  Safe, albeit rudimentary, Watcom support is provided by PNG_API_RULE==2
2944  Two new APIs exist to get the number of passes without turning on the
2945    PNG_INTERLACE transform and to get the number of rows in the current
2946    pass.
2947  A new test program, pngvalid.c, validates the gamma code.
2948  Errors in the 16-bit gamma correction (overflows) have been corrected.
2949  cHRM chunk testing is done consistently (previously the floating point
2950    API bypassed it, because the test really didn't work on FP, now the test
2951    is performed on the actual values to be stored in the PNG file so it
2952    works in the FP case too.)
2953  Most floating point APIs now simply call the fixed point APIs after
2954    converting the values to the fixed point form used in the PNG file.
2955  The standard headers no longer include zlib.h, which is currently only
2956    required for pngstruct.h and can therefore be internal.
2957  Revised png_get_int_32 to undo the PNG two's complement representation of
2958    negative numbers.
2959
2960Version 1.5.0beta37 [July 30, 2010]
2961  Added a typecast in png_get_int_32() in png.h and pngrutil.h to avoid
2962    a compiler warning.
2963  Replaced oFFs 0,0 with oFFs -10,20 in pngtest.png
2964
2965Version 1.5.0beta38 [July 31, 2010]
2966  Implemented remaining "_fixed" functions.
2967  Corrected a number of recently introduced warnings mostly resulting from
2968    safe but uncast assignments to shorter integers.  Also added a zlib
2969    VStudio release library project because the latest zlib Official Windows
2970    build does not include such a thing.
2971  Revised png_get_int_16() to be similar to png_get_int_32().
2972  Restored projects/visualc71.
2973
2974Version 1.5.0beta39 [August 2, 2010]
2975  VisualC/GCC warning fixes, VisualC build fixes
2976  The changes include support for function attributes in VC in addition to
2977    those already present in GCC - necessary because without these some
2978    warnings are unavoidable.  Fixes include signed/unsigned fixes in
2979    pngvalid and checks with gcc -Wall -Wextra -Wunused.
2980  VC requires function attributes on function definitions as well as
2981    declarations, PNG_FUNCTION has been added to enable this and the
2982    relevant function definitions changed.
2983
2984Version 1.5.0beta40 [August 6, 2010]
2985  Correct use of _WINDOWS_ in pngconf.h
2986  Removed png_mem_ #defines; they are no longer used.
2987  Added the sRGB chunk to pngtest.png
2988
2989Version 1.5.0beta41 [August 11, 2010]
2990  Added the cHRM chunk to pngtest.png
2991  Don't try to use version-script with cygwin/mingw.
2992  Revised contrib/gregbook to work under cygwin/mingw.
2993
2994Version 1.5.0beta42 [August 18, 2010]
2995  Add .dll.a to the list of extensions to be symlinked by Makefile.am (Yaakov)
2996  Made all API functions that have const arguments and constant string
2997    literal pointers declare them (John Bowler).
2998
2999Version 1.5.0beta43 [August 20, 2010]
3000  Removed spurious tabs, shorten long lines (no source change)
3001    Also added scripts/chkfmt to validate the format of all the files that can
3002    reasonably be validated (it is suggested to run "make distclean" before
3003    checking, because some machine generated files have long lines.)
3004  Reformatted the CHANGES file to be more consistent throughout.
3005  Made changes to address various issues identified by GCC, mostly
3006    signed/unsigned and shortening problems on assignment but also a few
3007    difficult to optimize (for GCC) loops.
3008  Fixed non-GCC fixed point builds.  In png.c a declaration was misplaced
3009    in an earlier update.  Fixed to declare the auto variables at the head.
3010  Use cexcept.h in pngvalid.c.
3011
3012Version 1.5.0beta44 [August 24, 2010]
3013  Updated CMakeLists.txt to use CMAKE_INSTALL_LIBDIR variable; useful for
3014    installing libpng in /usr/lib64 (Funda Wang).
3015  Revised CMakeLists.txt to put the man pages in share/man/man* not man/man*
3016  Revised CMakeLists.txt to make symlinks instead of copies when installing.
3017  Changed PNG_LIB_NAME from pngNN to libpngNN in CMakeLists.txt (Philip Lowman)
3018  Implemented memory checks within pngvalid
3019  Reformatted/rearranged pngvalid.c to assist use of progressive reader.
3020  Check interlaced images in pngvalid
3021  Clarified pngusr.h comments in pnglibconf.dfa
3022  Simplified the pngvalid error-handling code now that cexcept.h is in place.
3023  Implemented progressive reader in pngvalid.c for standard tests
3024  Implemented progressive read in pngvalid.c gamma tests
3025  Turn on progressive reader in pngvalid.c by default and tidy code.
3026
3027Version 1.5.0beta45 [August 26, 2010]
3028  Added an explicit make step to projects/vstudio for pnglibconf.h
3029    Also corrected zlib.vcxproj into which Visual Studio had introduced
3030    what it calls an "authoring error".  The change to make pnglibconf.h
3031    simply copies the file; in the future it may actually generate the
3032    file from scripts/pnglibconf.dfa as the other build systems do.
3033  Changed pngvalid to work when floating point APIs are disabled
3034  Renamed the prebuilt scripts/pnglibconf.h to scripts/pnglibconf.h.prebuilt
3035  Supply default values for PNG_USER_PRIVATEBUILD and PNG_USER_DLLFNAME_POSTFIX
3036    in pngpriv.h in case the user neglected to define them in their pngusr.h
3037
3038Version 1.5.0beta46 [August 28, 2010]
3039  Added new private header files to libpng_sources in CMakeLists.txt
3040  Added PNG_READ_16BIT, PNG_WRITE_16BIT, and PNG_16BIT options.
3041  Added reference to scripts/pnglibconf.h.prebuilt in the visualc71 project.
3042
3043Version 1.5.0beta47 [September 11, 2010]
3044  Fixed a number of problems with 64-bit compilation reported by Visual
3045    Studio 2010 (John Bowler).
3046
3047Version 1.5.0beta48 [October 4, 2010]
3048  Updated CMakeLists.txt (Philip Lowman).
3049  Revised autogen.sh to recognize and use $AUTOCONF, $AUTOMAKE, $AUTOHEADER,
3050    $AUTOPOINT, $ACLOCAL and $LIBTOOLIZE
3051  Fixed problem with symbols creation in Makefile.am which was assuming that
3052    all versions of ccp write to standard output by default (Martin Banky). The
3053    bug was introduced in libpng-1.2.9beta5.
3054  Removed unused mkinstalldirs.
3055
3056Version 1.5.0beta49 [October 8, 2010]
3057  Undid Makefile.am revision of 1.5.0beta48.
3058
3059Version 1.5.0beta50 [October 14, 2010]
3060  Revised Makefile.in to account for mkinstalldirs being removed.
3061  Added some "(unsigned long)" typecasts in printf statements in pngvalid.c.
3062  Suppressed a compiler warning in png_handle_sPLT().
3063  Check for out-of-range text compression mode in png_set_text().
3064
3065Version 1.5.0beta51 [October 15, 2010]
3066  Changed embedded dates to "(PENDING RELEASE) in beta releases (and future
3067    rc releases) to minimize the difference between releases.
3068
3069Version 1.5.0beta52 [October 16, 2010]
3070  Restored some of the embedded dates (in png.h, png.c, documentation, etc.)
3071
3072Version 1.5.0beta53 [October 18, 2010]
3073  Updated INSTALL to mention using "make maintainer-clean" and to remove
3074    obsolete statement about a custom ltmain.sh
3075  Disabled "color-tests" by default in Makefile.am so it will work with
3076    automake versions earlier than 1.11.1
3077  Use document name "libpng-manual.txt" instead of "libpng-<version>.txt"
3078    to simplify version differences.
3079  Removed obsolete remarks about setjmp handling from INSTALL.
3080  Revised and renamed the typedef in png.h and png.c that was designed
3081    to catch library and header mismatch.
3082
3083Version 1.5.0beta54 [November 10, 2010]
3084  Require 48 bytes, not 64 bytes, for big_row_buf in overflow checks.
3085  Used a consistent structure for the pngget.c functions.
3086
3087Version 1.5.0beta55 [November 21, 2010]
3088  Revised png_get_uint_32, png_get_int_32, png_get_uint_16 (Cosmin)
3089  Moved reading of file signature into png_read_sig (Cosmin)
3090  Fixed atomicity of chunk header serialization (Cosmin)
3091  Added test for io_state in pngtest.c (Cosmin)
3092  Added "#!/bin/sh" at the top of contrib/pngminim/*/gather.sh scripts.
3093  Changes to remove gcc warnings (John Bowler)
3094    Certain optional gcc warning flags resulted in warnings in libpng code.
3095    With these changes only -Wconversion and -Wcast-qual cannot be turned on.
3096    Changes are trivial rearrangements of code.  -Wconversion is not possible
3097    for pngrutil.c (because of the widespread use of += et al on variables
3098    smaller than (int) or (unsigned int)) and -Wcast-qual is not possible
3099    with pngwio.c and pngwutil.c because the 'write' callback and zlib
3100    compression both fail to declare their input buffers with 'const'.
3101
3102Version 1.5.0beta56 [December 7, 2010]
3103  Added the private PNG_UNUSED() macro definition in pngpriv.h.
3104  Added some commentary about PNG_EXPORT in png.h and pngconf.h
3105  Revised PNG_EXPORT() macro and added PNG_EXPORTA() macro, with the
3106    objective of simplifying and improving the cosmetic appearance of png.h.
3107  Fixed some incorrect "=" macro names in pnglibconf.dfa
3108  Included documentation of changes in 1.5.0 from 1.4.x in libpng-manual.txt
3109
3110Version 1.5.0beta57 [December 9, 2010]
3111  Documented the pngvalid gamma error summary with additional comments and
3112    print statements.
3113  Improved missing symbol handling in checksym.awk; symbols missing in both
3114    the old and new files can now be optionally ignored, treated as errors
3115    or warnings.
3116  Removed references to pngvcrd.c and pnggccrd.c from the vstudio project.
3117  Updated "libpng14" to "libpng15" in the visualc71 project.
3118  Enabled the strip16 tests in pngvalid.`
3119  Don't display test results (except PASS/FAIL) when running "make test".
3120    Instead put them in pngtest-log.txt
3121  Added "--with-zprefix=<string>" to configure.ac
3122  Updated the prebuilt configuration files to autoconf version 2.68
3123
3124Version 1.5.0beta58 [December 19, 2010]
3125  Fixed interlace image handling and add test cases (John Bowler)
3126  Fixed the clean rule in Makefile.am to remove pngtest-log.txt
3127  Made minor changes to work around warnings in gcc 3.4
3128
3129Version 1.5.0rc01 [December 27, 2010]
3130  No changes.
3131
3132Version 1.5.0rc02 [December 27, 2010]
3133  Eliminated references to the scripts/*.def files in project/visualc71.
3134
3135Version 1.5.0rc03 [December 28, 2010]
3136  Eliminated scripts/*.def and revised Makefile.am accordingly
3137
3138Version 1.5.0rc04 [December 29, 2010]
3139  Fixed bug in background transformation handling in pngrtran.c (it was
3140    looking for the flag in png_ptr->transformations instead of in
3141    png_ptr->flags) (David Raymond).
3142
3143Version 1.5.0rc05 [December 31, 2010]
3144  Fixed typo in a comment in CMakeLists.txt (libpng14 => libpng15) (Cosmin)
3145
3146Version 1.5.0rc06 [January 4, 2011]
3147  Changed the new configure option "zprefix=string" to "zlib-prefix=string"
3148
3149Version 1.5.0rc07 [January 4, 2011]
3150  Updated copyright year.
3151
3152Version 1.5.0 [January 6, 2011]
3153  No changes.
3154
3155version 1.5.1beta01 [January 8, 2011]
3156  Added description of png_set_crc_action() to the manual.
3157  Added a note in the manual that the type of the iCCP profile was changed
3158    from png_charpp to png_bytepp in png_get_iCCP().  This change happened
3159    in version 1.5.0beta36 but is not noted in the CHANGES.  Similarly,
3160    it was changed from png_charpp to png_const_bytepp in png_set_iCCP().
3161  Ensure that png_rgb_to_gray ignores palette mapped images, if libpng
3162    internally happens to call it with one, and fixed a failure to handle
3163    palette mapped images correctly.  This fixes CVE-2690.
3164
3165Version 1.5.1beta02 [January 14, 2011]
3166  Fixed a bug in handling of interlaced images (bero at arklinux.org).
3167  Updated CMakeLists.txt (Clifford Yapp)
3168
3169Version 1.5.1beta03 [January 14, 2011]
3170  Fixed typecasting of some png_debug() statements (Cosmin)
3171
3172Version 1.5.1beta04 [January 16, 2011]
3173  Updated documentation of png_set|get_tRNS() (Thomas Klausner).
3174  Mentioned in the documentation that applications must #include "zlib.h"
3175    if they need access to anything in zlib.h, and that a number of
3176    macros such as png_memset() are no longer accessible by applications.
3177  Corrected pngvalid gamma test "sample" function to access all of the color
3178    samples of each pixel, instead of sampling the red channel three times.
3179  Prefixed variable names index, div, exp, gamma with "png_" to avoid "shadow"
3180    warnings, and (mistakenly) changed png_exp() to exp().
3181
3182Version 1.5.1beta05 [January 16, 2011]
3183  Changed variable names png_index, png_div, png_exp, and png_gamma to
3184    char_index, divisor, exp_b10, and gamma_val, respectively, and
3185    changed exp() back to png_exp().
3186
3187Version 1.5.1beta06 [January 20, 2011]
3188  Prevent png_push_crc_skip() from hanging while reading an unknown chunk
3189    or an over-large compressed zTXt chunk with the progressive reader.
3190  Eliminated more GCC "shadow" warnings.
3191  Revised png_fixed() in png.c to avoid compiler warning about reaching the
3192    end without returning anything.
3193
3194Version 1.5.1beta07 [January 22, 2011]
3195  In the manual, describe the png_get_IHDR() arguments in the correct order.
3196  Added const_png_structp and const_png_infop types, and used them in
3197    prototypes for most png_get_*() functions.
3198
3199Version 1.5.1beta08 [January 23, 2011]
3200  Added png_get_io_chunk_type() and deprecated png_get_io_chunk_name()
3201  Added synopses for the IO_STATE functions and other missing synopses
3202    to the manual. Removed the synopses from libpngpf.3 because they
3203    were out of date and no longer useful.  Better information can be
3204    obtained by reading the prototypes and comments in pngpriv.h
3205  Attempted to fix cpp on Solaris with S. Studio 12 cc, fix build
3206    Added a make macro DFNCPP that is a CPP that will accept the tokens in
3207    a .dfn file and adds configure stuff to test for such a CPP.  ./configure
3208    should fail if one is not available.
3209  Corrected const_png_ in png.h to png_const_ to avoid polluting the namespace.
3210  Added png_get_current_row_number and png_get_current_pass_number for the
3211    benefit of the user transform callback.
3212  Added png_process_data_pause and png_process_data_skip for the benefit of
3213    progressive readers that need to stop data processing or want to optimize
3214    skipping of unread data (e.g., if the reader marks a chunk to be skipped.)
3215
3216Version 1.5.1beta09 [January 24, 2011]
3217  Enhanced pngvalid, corrected an error in gray_to_rgb, corrected doc error.
3218    pngvalid contains tests of transforms, which tests are currently disabled
3219    because they are incompletely tested.  gray_to_rgb was failing to expand
3220    the bit depth for smaller bit depth images; this seems to be a long
3221    standing error and resulted, apparently, in invalid output
3222    (CVE-2011-0408, CERT VU#643140).  The documentation did not accurately
3223    describe what libpng really does when converting RGB to gray.
3224
3225Version 1.5.1beta10 [January 27, 2010]
3226  Fixed incorrect examples of callback prototypes in the manual, that were
3227    introduced in libpng-1.0.0.
3228  In addition the order of the png_get_uint macros with respect to the
3229    relevant function definitions has been reversed.  This helps the
3230    preprocessing of the symbol files be more robust.  Furthermore, the
3231    symbol file preprocessing now uses -DPNG_NO_USE_READ_MACROS even when
3232    the library may actually be built with PNG_USE_READ_MACROS; this stops
3233    the read macros interfering with the symbol file format.
3234  Made the manual, synopses, and function prototypes use the function
3235    argument names file_gamma, int_file_gamma, and srgb_intent consistently.
3236
3237Version 1.5.1beta11 [January 28, 2011]
3238  Changed PNG_UNUSED from "param=param;" to "{if(param){}}".
3239  Corrected local variable type in new API png_process_data_skip()
3240    The type was self-evidently incorrect but only causes problems on 64-bit
3241    architectures.
3242  Added transform tests to pngvalid and simplified the arguments.
3243
3244Version 1.5.1rc01 [January 29, 2011]
3245  No changes.
3246
3247Version 1.5.1rc02 [January 31, 2011]
3248  Added a request in the manual that applications do not use "png_" or
3249    "PNG_" to begin any of their own symbols.
3250  Changed PNG_UNUSED to "(void)param;" and updated the commentary in pngpriv.h
3251
3252Version 1.5.1 [February 3, 2011]
3253  No changes.
3254
3255Version 1.5.2beta01 [February 13, 2011]
3256  More -Wshadow fixes for older gcc compilers.  Older gcc versions apparently
3257    check formal parameters names in function declarations (as well as
3258    definitions) to see if they match a name in the global namespace.
3259  Revised PNG_EXPORTA macro to not use an empty parameter, to accommodate the
3260    old VisualC++ preprocessor.
3261  Turned on interlace handling in png_read_png().
3262  Fixed gcc pendantic warnings.
3263  Handle longjmp in Cygwin.
3264  Fixed png_get_current_row_number() in the interlaced case.
3265  Cleaned up ALPHA flags and transformations.
3266  Implemented expansion to 16 bits.
3267
3268Version 1.5.2beta02 [February 19, 2011]
3269  Fixed mistake in the descriptions of user read_transform and write_transform
3270    function prototypes in the manual.  The row_info struct is png_row_infop.
3271  Reverted png_get_current_row_number() to previous (1.5.2beta01) behavior.
3272  Corrected png_get_current_row_number documentation
3273  Fixed the read/write row callback documentation.
3274    This documents the current behavior, where the callback is called after
3275    every row with information pertaining to the next row.
3276
3277Version 1.5.2beta03 [March 3, 2011]
3278  Fixed scripts/makefile.vcwin32
3279  Updated contrib/pngsuite/README to add the word "modify".
3280  Define PNG_ALLOCATED to blank when _MSC_VER<1300.
3281
3282Version 1.5.2rc01 [March 19, 2011]
3283  Define remaining attributes to blank when MSC_VER<1300.
3284  ifdef out mask arrays in pngread.c when interlacing is not supported.
3285
3286Version 1.5.2rc02 [March 22, 2011]
3287  Added a hint to try CPP=/bin/cpp if "cpp -E" fails in scripts/pnglibconf.mak
3288    and in contrib/pngminim/*/makefile, eg., on SunOS 5.10, and removed "strip"
3289    from the makefiles.
3290  Fixed a bug (present since libpng-1.0.7) that makes png_handle_sPLT() fail
3291    to compile when PNG_NO_POINTER_INDEXING is defined (Chubanov Kirill)
3292
3293Version 1.5.2rc03 [March 24, 2011]
3294  Don't include standard header files in png.h while building the symbol table,
3295    to avoid cpp failure on SunOS (introduced PNG_BUILDING_SYMBOL_TABLE macro).
3296
3297Version 1.5.2 [March 31, 2011]
3298  No changes.
3299
3300Version 1.5.3beta01 [April 1, 2011]
3301  Re-initialize the zlib compressor before compressing non-IDAT chunks.
3302  Added API functions (png_set_text_compression_level() and four others) to
3303    set parameters for zlib compression of non-IDAT chunks.
3304
3305Version 1.5.3beta02 [April 3, 2011]
3306  Updated scripts/symbols.def with new API functions.
3307  Only compile the new zlib re-initializing code when text or iCCP is
3308    supported, using PNG_WRITE_COMPRESSED_TEXT_SUPPORTED macro.
3309  Improved the optimization of the zlib CMF byte (see libpng-1.2.6beta03).
3310  Optimize the zlib CMF byte in non-IDAT compressed chunks
3311
3312Version 1.5.3beta03 [April 16, 2011]
3313  Fixed gcc -ansi -pedantic compile. A strict ANSI system does not have
3314    snprintf, and the "__STRICT_ANSI__" detects that condition more reliably
3315    than __STDC__ (John Bowler).
3316  Removed the PNG_PTR_NORETURN attribute because it too dangerous. It tells
3317    the compiler that a user supplied callback (the error handler) does not
3318    return, yet there is no guarantee in practice that the application code
3319    will correctly implement the error handler because the compiler only
3320    issues a warning if there is a mistake (John Bowler).
3321  Removed the no-longer-used PNG_DEPSTRUCT macro.
3322  Updated the zlib version to 1.2.5 in the VStudio project.
3323  Fixed 64-bit builds where png_uint_32 is smaller than png_size_t in
3324    pngwutil.c (John Bowler).
3325  Fixed bug with stripping the filler or alpha channel when writing, that
3326    was introduced in libpng-1.5.2beta01 (bug report by Andrew Church).
3327
3328Version 1.5.3beta04 [April 27, 2011]
3329  Updated pngtest.png with the new zlib CMF optimization.
3330  Cleaned up conditional compilation code and of background/gamma handling
3331    Internal changes only except a new option to avoid compiling the
3332    png_build_grayscale_palette API (which is not used at all internally.)
3333    The main change is to move the transform tests (READ_TRANSFORMS,
3334    WRITE_TRANSFORMS) up one level to the caller of the APIs.  This avoids
3335    calls to spurious functions if all transforms are disabled and slightly
3336    simplifies those functions.  Pngvalid modified to handle this.
3337    A minor change is to stop the strip_16 and expand_16 interfaces from
3338    disabling each other; this allows the future alpha premultiplication
3339    code to use 16-bit intermediate values while still producing 8-bit output.
3340    png_do_background and png_do_gamma have been simplified to take a single
3341    pointer to the png_struct rather than pointers to every item required
3342    from the png_struct. This makes no practical difference to the internal
3343    code.
3344  A serious bug in the pngvalid internal routine 'standard_display_init' has
3345    been fixed - this failed to initialize the red channel and accidentally
3346    initialized the alpha channel twice.
3347  Changed png_struct jmp_buf member name from png_jmpbuf to tmp_jmpbuf to
3348    avoid a possible clash with the png_jmpbuf macro on some platforms.
3349
3350Version 1.5.3beta05 [May 6, 2011]
3351  Added the "_POSIX_SOURCE" feature test macro to ensure libpng sees the
3352    correct API. _POSIX_SOURCE is defined in pngpriv.h, pngtest.c and
3353    pngvalid.c to ensure that POSIX conformant systems disable non-POSIX APIs.
3354  Removed png_snprintf and added formatted warning messages.  This change adds
3355    internal APIs to allow png_warning messages to have parameters without
3356    requiring the host OS to implement snprintf.  As a side effect the
3357    dependency of the tIME-supporting RFC1132 code on stdio is removed and
3358    PNG_NO_WARNINGS does actually work now.
3359  Pass "" instead of '\0' to png_default_error() in png_err().  This mistake
3360    was introduced in libpng-1.2.20beta01.  This fixes CVE-2011-2691.
3361  Added PNG_WRITE_OPTIMIZE_CMF_SUPPORTED macro to make the zlib "CMF" byte
3362    optimization configureable.
3363  IDAT compression failed if preceded by a compressed text chunk (bug
3364    introduced in libpng-1.5.3beta01-02).  This was because the attempt to
3365    reset the zlib stream in png_write_IDAT happened after the first IDAT
3366    chunk had been deflated - much too late.  In this change internal
3367    functions were added to claim/release the z_stream and, hopefully, make
3368    the code more robust.  Also deflateEnd checking is added - previously
3369    libpng would ignore an error at the end of the stream.
3370
3371Version 1.5.3beta06 [May 8, 2011]
3372  Removed the -D_ALL_SOURCE from definitions for AIX in CMakeLists.txt
3373  Implemented premultiplied alpha support: png_set_alpha_mode API
3374
3375Version 1.5.3beta07 [May 11, 2011]
3376  Added expand_16 support to the high level interface.
3377  Added named value and 'flag' gamma support to png_set_gamma.  Made a minor
3378    change from the previous (unreleased) ABI/API to hide the exact value used
3379    for Macs - it's not a good idea to embed this in the ABI!
3380  Moved macro definitions for PNG_HAVE_IHDR, PNG_HAVE_PLTE, and PNG_AFTER_IDAT
3381    from pngpriv.h to png.h because they must be visible to applications
3382    that call png_set_unknown_chunks().
3383  Check for up->location !PNG_AFTER_IDAT when writing unknown chunks
3384    before IDAT.
3385
3386Version 1.5.3beta08 [May 16, 2011]
3387  Improved "pngvalid --speed" to exclude more of pngvalid from the time.
3388  Documented png_set_alpha_mode(), other changes in libpng.3/libpng-manual.txt
3389  The cHRM chunk now sets the defaults for png_set_rgb_to_gray() (when negative
3390    parameters are supplied by the caller), while in the absence of cHRM
3391    sRGB/Rec 709 values are still used.  This introduced a divide-by-zero
3392    bug in png_handle_cHRM().
3393  The bKGD chunk no longer overwrites the background value set by
3394    png_set_background(), allowing the latter to be used before the file
3395    header is read. It never performed any useful function to override
3396    the default anyway.
3397  Added memory overwrite and palette image checks to pngvalid.c
3398    Previously palette image code was poorly checked. Since the transformation
3399    code has a special palette path in most cases this was a severe weakness.
3400  Minor cleanup and some extra checking in pngrutil.c and pngrtran.c. When
3401    expanding an indexed image, always expand to RGBA if transparency is
3402    present.
3403
3404Version 1.5.3beta09 [May 17, 2011]
3405  Reversed earlier 1.5.3 change of transformation order; move png_expand_16
3406    back where it was.  The change doesn't work because it requires 16-bit
3407    gamma tables when the code only generates 8-bit ones.  This fails
3408    silently; the libpng code just doesn't do any gamma correction.  Moving
3409    the tests back leaves the old, inaccurate, 8-bit gamma calculations, but
3410    these are clearly better than none!
3411
3412Version 1.5.3beta10 [May 20, 2011]
3413
3414  png_set_background() and png_expand_16() did not work together correctly.
3415    This problem is present in 1.5.2; if png_set_background is called with
3416    need_expand false and the matching 16 bit color libpng erroneously just
3417    treats it as an 8-bit color because of where png_do_expand_16 is in the
3418    transform list.  This simple fix reduces the supplied colour to 8-bits,
3419    so it gets smashed, but this is better than the current behavior.
3420  Added tests for expand16, more fixes for palette image tests to pngvalid.
3421    Corrects the code for palette image tests and disables attempts to
3422    validate palette colors.
3423
3424Version 1.5.3rc01 [June 3, 2011]
3425  No changes.
3426
3427Version 1.5.3rc02 [June 8, 2011]
3428  Fixed uninitialized memory read in png_format_buffer() (Bug report by
3429    Frank Busse, CVE-2011-2501, related to CVE-2004-0421).
3430
3431Version 1.5.3beta11 [June 11, 2011]
3432  Fixed png_handle_sCAL which is broken in 1.5. This fixes CVE 2011-2692.
3433  Added sCAL to pngtest.png
3434  Revised documentation about png_set_user_limits() to say that it also affects
3435    png writing.
3436  Revised handling of png_set_user_limits() so that it can increase the
3437    limit beyond the PNG_USER_WIDTH|HEIGHT_MAX; previously it could only
3438    reduce it.
3439  Make the 16-to-8 scaling accurate. Dividing by 256 with no rounding is
3440    wrong (high by one) 25% of the time. Dividing by 257 with rounding is
3441    wrong in 128 out of 65536 cases. Getting the right answer all the time
3442    without division is easy.
3443  Added "_SUPPORTED" to the PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION macro.
3444  Added projects/owatcom, an IDE project for OpenWatcom to replace
3445    scripts/makefile.watcom.  This project works with OpenWatcom 1.9. The
3446    IDE autogenerates appropriate makefiles (libpng.mk) for batch processing.
3447    The project is configurable, unlike the Visual Studio project, so long
3448    as the developer has an awk.
3449  Changed png_set_gAMA to limit the gamma value range so that the inverse
3450    of the stored value cannot overflow the fixed point representation,
3451    and changed other things OpenWatcom warns about.
3452  Revised pngvalid.c to test PNG_ALPHA_MODE_SUPPORTED correctly. This allows
3453    pngvalid to build when ALPHA_MODE is not supported, which is required if
3454    it is to build on libpng 1.4.
3455  Removed string/memory macros that are no longer used and are not
3456    necessarily fully supportable, particularly png_strncpy and png_snprintf.
3457  Added log option to pngvalid.c and attempted to improve gamma messages.
3458
3459Version 1.5.3 [omitted]
3460  People found the presence of a beta release following an rc release
3461    to be confusing; therefore we bump the version to libpng-1.5.4beta01
3462    and there will be no libpng-1.5.3 release.
3463
3464Version 1.5.4beta01 [June 14, 2011]
3465  Made it possible to undefine PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
3466    to get the same (inaccurate) output as libpng-1.5.2 and earlier.
3467  Moved definitions of PNG_HAVE_IHDR, PNG_AFTER_IDAT, and PNG_HAVE_PLTE
3468    outside of an unknown-chunk block in png.h because they are also
3469    needed for other uses.
3470
3471Version 1.5.4beta02 [June 14, 2011]
3472  Fixed and clarified LEGACY 16-to-8 scaling code.
3473  Added png_set_chop_16() API, to match inaccurate results from previous
3474    libpng versions.
3475  Removed the ACCURATE and LEGACY options (they are no longer useable)
3476  Use the old scaling method for background if png_set_chop_16() was
3477    called.
3478  Made png_set_chop_16() API removeable by disabling PNG_CHOP_16_TO_8_SUPPORTED
3479
3480Version 1.5.4beta03 [June 15, 2011]
3481  Fixed a problem in png_do_expand_palette() exposed by optimization in
3482    1.5.3beta06
3483  Also removed a spurious and confusing "trans" member ("trans") from png_info.
3484  The palette expand optimization prevented expansion to an intermediate RGBA
3485    form if tRNS was present but alpha was marked to be stripped; this exposed
3486    a check for tRNS in png_do_expand_palette() which is inconsistent with the
3487    code elsewhere in libpng.
3488  Correction to the expand_16 code; removed extra instance of
3489    png_set_scale_16_to_8 from pngpriv.h
3490
3491Version 1.5.4beta04 [June 16, 2011]
3492  Added a missing "#ifdef PNG_READ_BACKGROUND_SUPPORTED/#endif" in pngrtran.c
3493  Added PNG_TRANSFORM_CHOP_16 to the high-level read transforms.
3494  Made PNG_READ_16_TO_8_ACCURATE_SCALE configurable again.  If this is
3495    not enabled, png_set_strip_16() and png_do_scale_16_to_8() aren't built.
3496  Revised contrib/visupng, gregbook, and pngminim to demonstrate chop_16_to_8
3497
3498Version 1.5.4beta05 [June 16, 2011]
3499  Renamed png_set_strip_16() to png_set_scale_16() and renamed
3500    png_set_chop_16() to png_set_strip(16) in an attempt to minimize the
3501    behavior changes between libpng14 and libpng15.
3502
3503Version 1.5.4beta06 [June 18, 2011]
3504  Fixed new bug that was causing both strip_16 and scale_16 to be applied.
3505
3506Version 1.5.4beta07 [June 19, 2011]
3507  Fixed pngvalid, simplified macros, added checking for 0 in sCAL.
3508    The ACCURATE scale macro is no longer defined in 1.5 - call the
3509    png_scale_16_to_8 API.  Made sure that PNG_READ_16_TO_8 is still defined
3510    if the png_strip_16_to_8 API is present.  png_check_fp_number now
3511    maintains some state so that positive, negative and zero values are
3512    identified.  sCAL uses these to be strictly spec conformant.
3513
3514Version 1.5.4beta08 [June 23, 2011]
3515  Fixed pngvalid if ACCURATE_SCALE is defined.
3516  Updated scripts/pnglibconf.h.prebuilt.
3517
3518Version 1.5.4rc01 [June 30, 2011]
3519  Define PNG_ALLOCATED to "restrict" only if MSC_VER >= 1400.
3520
3521Version 1.5.4 [July 7, 2011]
3522  No changes.
3523
3524Version 1.5.5beta01 [July 13, 2011]
3525  Fixed some typos and made other minor changes in the manual.
3526  Updated contrib/pngminus/makefile.std (Samuli Souminen)
3527
3528Version 1.5.5beta02 [July 14, 2011]
3529  Revised Makefile.am and Makefile.in to look in the right directory for
3530    pnglibconf.h.prebuilt
3531
3532Version 1.5.5beta03 [July 27, 2011]
3533  Enabled compilation with g++ compiler.  This compiler does not recognize
3534    the file extension, so it always compiles with C++ rules.  Made minor
3535    changes to pngrutil.c to cast results where C++ expects it but C does not.
3536  Minor editing of libpng.3 and libpng-manual.txt.
3537
3538Version 1.5.5beta04 [July 29, 2011]
3539  Revised CMakeLists.txt (Clifford Yapp)
3540  Updated commentary about the png_rgb_to_gray() default coefficients
3541    in the manual and in pngrtran.c
3542
3543Version 1.5.5beta05 [August 17, 2011]
3544  Prevent unexpected API exports from non-libpng DLLs on Windows.  The "_DLL"
3545    is removed from the test of whether a DLL is being built (this erroneously
3546    caused the libpng APIs to be marked as DLL exports in static builds under
3547    Microsoft Visual Studio).  Almost all of the libpng building configuration
3548    is moved from pngconf.h to pngpriv.h, but PNG_DLL_EXPORT remains in
3549    pngconf.h, though, so that it is colocated with the import definition (it
3550    is no longer used anywhere in the installed headers).  The VStudio project
3551    definitions have been cleaned up: "_USRDLL" has been removed from the
3552    static library builds (this was incorrect), and PNG_USE_DLL has been added
3553    to pngvalid to test the functionality (pngtest does not supply it,
3554    deliberately).  The spurious "_EXPORTS" has been removed from the
3555    libpng build (all these errors were a result of copy/paste between project
3556    configurations.)
3557  Added new types and internal functions for CIE RGB end point handling to
3558    pngpriv.h (functions yet to be implemented).
3559
3560Version 1.5.5beta06 [August 26, 2011]
3561  Ensure the CMAKE_LIBRARY_OUTPUT_DIRECTORY is set in CMakeLists.txt
3562    (Clifford Yap)
3563  Fixes to rgb_to_gray and cHRM XYZ APIs (John Bowler):
3564    The rgb_to_gray code had errors when combined with gamma correction.
3565    Some pixels were treated as true grey when they weren't and such pixels
3566    and true grey ones were not gamma corrected (the original value of the
3567    red component was used instead).  APIs to get and set cHRM using color
3568    space end points have been added and the rgb_to_gray code that defaults
3569    based on cHRM, and the divide-by-zero bug in png_handle_cHRM (CERT
3570    VU#477046, CVE-2011-3328, introduced in 1.5.4) have been corrected.
3571  A considerable number of tests has been added to pngvalid for the
3572    rgb_to_gray transform.
3573  Arithmetic errors in rgb_to_gray whereby the calculated gray value was
3574    truncated to the bit depth rather than rounded have been fixed except in
3575    the 8-bit non-gamma-corrected case (where consistency seems more important
3576    than correctness.)  The code still has considerable inaccuracies in the
3577    8-bit case because 8-bit linear arithmetic is used.
3578
3579Version 1.5.5beta07 [September 7, 2011]
3580  Added "$(ARCH)" option to makefile.darwin
3581  Added SunOS support to configure.ac and Makefile.am
3582  Changed png_chunk_benign_error() to png_warning() in png.c, in
3583    png_XYZ_from_xy_checked().
3584
3585Version 1.5.5beta08 [September 10, 2011]
3586  Fixed 64-bit compilation errors (gcc). The errors fixed relate
3587    to conditions where types that are 32 bits in the GCC 32-bit
3588    world (uLong and png_size_t) become 64 bits in the 64-bit
3589    world.  This produces potential truncation errors which the
3590    compiler correctly flags.
3591  Relocated new HAVE_SOLARIS_LD definition in configure.ac
3592  Constant changes for 64-bit compatibility (removal of L suffixes). The
3593    16-bit cases still use "L" as we don't have a 16-bit test system.
3594
3595Version 1.5.5rc01 [September 15, 2011]
3596  Removed "L" suffixes in pngpriv.h
3597
3598Version 1.5.5 [September 22, 2011]
3599  No changes.
3600
3601Version 1.5.6beta01 [September 22, 2011]
3602  Fixed some 64-bit type conversion warnings in pngrtran.c
3603  Moved row_info from png_struct to a local variable.
3604  The various interlace mask arrays have been made into arrays of
3605    bytes and made PNG_CONST and static (previously some arrays were
3606    marked PNG_CONST and some weren't).
3607  Additional checks have been added to the transform code to validate the
3608    pixel depths after the transforms on both read and write.
3609  Removed some redundant code from pngwrite.c, in png_destroy_write_struct().
3610  Changed chunk reading/writing code to use png_uint_32 instead of png_byte[4].
3611    This removes the need to allocate temporary strings for chunk names on
3612    the stack in the read/write code.  Unknown chunk handling still uses the
3613    string form because this is exposed in the API.
3614
3615Version 1.5.6beta02 [September 26, 2011]
3616  Added a note in the manual the png_read_update_info() must be called only
3617    once with a particular info_ptr.
3618  Fixed a typo in the definition of the new PNG_STRING_FROM_CHUNK(s,c) macro.
3619
3620Version 1.5.6beta03 [September 28, 2011]
3621  Revised test-pngtest.sh to report FAIL when pngtest fails.
3622  Added "--strict" option to pngtest, to report FAIL when the failure is
3623    only because the resulting valid files are different.
3624  Revised CMakeLists.txt to work with mingw and removed some material from
3625    CMakeLists.txt that is no longer useful in libpng-1.5.
3626
3627Version 1.5.6beta04 [October 5, 2011]
3628  Fixed typo in Makefile.in and Makefile.am ("-M Wl" should be "-M -Wl")."
3629
3630Version 1.5.6beta05 [October 12, 2011]
3631  Speed up png_combine_row() for interlaced images. This reduces the generality
3632    of the code, allowing it to be optimized for Adam7 interlace.  The masks
3633    passed to png_combine_row() are now generated internally, avoiding
3634    some code duplication and localizing the interlace handling somewhat.
3635  Align png_struct::row_buf - previously it was always unaligned, caused by
3636    a bug in the code that attempted to align it; the code needs to subtract
3637    one from the pointer to take account of the filter byte prepended to
3638    each row.
3639  Optimized png_combine_row() when rows are aligned. This gains a small
3640    percentage for 16-bit and 32-bit pixels in the typical case where the
3641    output row buffers are appropriately aligned. The optimization was not
3642    previously possible because the png_struct buffer was always misaligned.
3643  Fixed bug in png_write_chunk_header() debug print, introduced in 1.5.6beta01.
3644
3645Version 1.5.6beta06 [October 17, 2011]
3646  Removed two redundant tests for unitialized row.
3647  Fixed a relatively harmless memory overwrite in compressed text writing
3648    with a 1 byte zlib buffer.
3649  Add ability to call png_read_update_info multiple times to pngvalid.c.
3650  Fixes for multiple calls to png_read_update_info. These fixes attend to
3651    most of the errors revealed in pngvalid, however doing the gamma work
3652    twice results in inaccuracies that can't be easily fixed.  There is now
3653    a warning in the code if this is going to happen.
3654  Turned on multiple png_read_update_info in pngvalid transform tests.
3655  Prevent libpng from overwriting unused bits at the end of the image when
3656    it is not byte aligned, while reading. Prior to libpng-1.5.6 libpng would
3657    overwrite the partial byte at the end of each row if the row width was not
3658    an exact multiple of 8 bits and the image is not interlaced.
3659
3660Version 1.5.6beta07 [October 21, 2011]
3661  Made png_ptr->prev_row an aligned pointer into png_ptr->big_prev_row
3662    (Mans Rullgard).
3663
3664Version 1.5.6rc01 [October 26, 2011]
3665  Changed misleading "Missing PLTE before cHRM" warning to "Out of place cHRM"
3666
3667Version 1.5.6rc02 [October 27, 2011]
3668  Added LSR() macro to defend against buggy compilers that evaluate non-taken
3669    code branches and complain about out-of-range shifts.
3670
3671Version 1.5.6rc03 [October 28, 2011]
3672  Renamed the LSR() macro to PNG_LSR() and added PNG_LSL() macro.
3673  Fixed compiler warnings with Intel and MSYS compilers. The logical shift
3674    fix for Microsoft Visual C is required by other compilers, so this
3675    enables that fix for all compilers when using compile-time constants.
3676    Under MSYS 'byte' is a name declared in a system header file, so we
3677    changed the name of a local variable to avoid the warnings that result.
3678  Added #define PNG_ALIGN_TYPE PNG_ALIGN_NONE to contrib/pngminim/*/pngusr.h
3679
3680Version 1.5.6 [November 3, 2011]
3681  No changes.
3682
3683Version 1.5.7beta01 [November 4, 2011]
3684  Added support for ARM processor, when decoding all PNG up-filtered rows
3685    and any other-filtered rows with 3 or 4 bytes per pixel (Mans Rullgard).
3686  Fixed bug in pngvalid on early allocation failure; fixed type cast in
3687    pngmem.c; pngvalid would attempt to call png_error() if the allocation
3688    of a png_struct or png_info failed. This would probably have led to a
3689    crash.  The pngmem.c implementation of png_malloc() included a cast
3690    to png_size_t which would fail on large allocations on 16-bit systems.
3691  Fix for the preprocessor of the Intel C compiler. The preprocessor
3692    splits adjacent @ signs with a space; this changes the concatentation
3693    token from @-@-@ to PNG_JOIN; that should work with all compiler
3694    preprocessors.
3695  Paeth filter speed improvements from work by Siarhei Siamashka. This
3696    changes the 'Paeth' reconstruction function to improve the GCC code
3697    generation on x86. The changes are only part of the suggested ones;
3698    just the changes that definitely improve speed and remain simple.
3699    The changes also slightly increase the clarity of the code.
3700
3701Version 1.5.7beta02 [November 11, 2011]
3702  Check compression_type parameter in png_get_iCCP and remove spurious
3703    casts. The compression_type parameter is always assigned to, so must
3704    be non-NULL. The cast of the profile length potentially truncated the
3705    value unnecessarily on a 16-bit int system, so the cast of the (byte)
3706    compression type to (int) is specified by ANSI-C anyway.
3707  Fixed FP division by zero in pngvalid.c; the 'test_pixel' code left
3708    the sBIT fields in the test pixel as 0, which resulted in a floating
3709    point division by zero which was irrelevant but causes systems where
3710    FP exceptions cause a crash. Added code to pngvalid to turn on FP
3711    exceptions if the appropriate glibc support is there to ensure this is
3712    tested in the future.
3713  Updated scripts/pnglibconf.mak and scripts/makefile.std to handle the
3714    new PNG_JOIN macro.
3715  Added versioning to pnglibconf.h comments.
3716  Simplified read/write API initial version; basic read/write tested on
3717    a variety of images, limited documentation (in the header file.)
3718  Installed more accurate linear to sRGB conversion tables. The slightly
3719    modified tables reduce the number of 16-bit values that
3720    convert to an off-by-one 8-bit value.  The "makesRGB.c" code that was used
3721    to generate the tables is now in a contrib/sRGBtables sub-directory.
3722
3723Version 1.5.7beta03 [November 17, 2011]
3724  Removed PNG_CONST from the sRGB table declarations in pngpriv.h and png.c
3725  Added run-time detection of NEON support.
3726  Added contrib/libtests; includes simplified API test and timing test and
3727    a color conversion utility for rapid checking of failed 'pngstest' results.
3728  Multiple transform bug fixes plus a work-round for double gamma correction.
3729    libpng does not support more than one transform that requires linear data
3730    at once - if this is tried typically the results is double gamma
3731    correction. Since the simplified APIs can need rgb to gray combined with
3732    a compose operation it is necessary to do one of these outside the main
3733    libpng transform code. This check-in also contains fixes to various bugs
3734    in the simplified APIs themselves and to some bugs in compose and rgb to
3735    gray (on palette) itself.
3736  Fixes for C++ compilation using g++ When libpng source is compiled
3737    using g++. The compiler imposes C++ rules on the C source; thus it
3738    is desireable to make the source work with either C or C++ rules
3739    without throwing away useful error information.  This change adds
3740    png_voidcast to allow C semantic (void*) cases or the corresponding
3741    C++ static_cast operation, as appropriate.
3742  Added --noexecstack to assembler file compilation. GCC does not set
3743    this on assembler compilation, even though it does on C compilation.
3744    This creates security issues if assembler code is enabled; the
3745    work-around is to set it by default in the flags for $(CCAS)
3746  Work around compilers that don't support declaration of const data. Some
3747    compilers fault 'extern const' data declarations (because the data is
3748    not initialized); this turns on const-ness only for compilers where
3749    this is known to work.
3750
3751Version 1.5.7beta04 [November 17, 2011]
3752  Since the gcc driver does not recognize the --noexecstack flag, we must
3753    use the -Wa prefix to have it passed through to the assembler.
3754    Also removed a duplicate setting of this flag.
3755  Added files that were omitted from the libpng-1.5.7beta03 zip distribution.
3756
3757Version 1.5.7beta05 [November 25, 2011]
3758  Removed "zTXt" from warning in generic chunk decompression function.
3759  Validate time settings passed to png_set_tIME() and png_convert_to_rfc1123()
3760    (Frank Busse). Note: This prevented CVE-2015-7981 from affecting
3761    libpng-1.5.7 and later.
3762  Added MINGW support to CMakeLists.txt
3763  Reject invalid compression flag or method when reading the iTXt chunk.
3764  Backed out 'simplified' API changes. The API seems too complex and there
3765    is a lack of consensus or enthusiasm for the proposals.  The API also
3766    reveals significant bugs inside libpng (double gamma correction and the
3767    known bug of being unable to retrieve a corrected palette). It seems
3768    better to wait until the bugs, at least, are corrected.
3769  Moved pngvalid.c into contrib/libtests
3770  Rebuilt Makefile.in, configure, etc., with autoconf-2.68
3771
3772Version 1.5.7rc01 [December 1, 2011]
3773  Replaced an "#if" with "#ifdef" in pngrtran.c
3774  Revised #if PNG_DO_BC block in png.c (use #ifdef and add #else)
3775
3776Version 1.5.7rc02 [December 5, 2011]
3777  Revised project files and contrib/pngvalid/pngvalid.c to account for
3778    the relocation of pngvalid into contrib/libtests.
3779  Revised pngconf.h to use " __declspec(restrict)" only when MSC_VER >= 1400,
3780    as in libpng-1.5.4.
3781  Put CRLF line endings in the owatcom project files.
3782
3783Version 1.5.7rc03 [December 7, 2011]
3784  Updated CMakeLists.txt to account for the relocation of pngvalid.c
3785
3786Version 1.5.7 [December 15, 2011]
3787  Minor fixes to pngvalid.c for gcc 4.6.2 compatibility to remove warnings
3788    reported by earlier versions.
3789  Fixed minor memset/sizeof errors in pngvalid.c.
3790
3791Version 1.6.0beta01 [December 15, 2011]
3792  Removed machine-generated configure files from the GIT repository (they will
3793    continue to appear in the tarball distributions and in the libpng15 and
3794    earlier GIT branches).
3795  Restored the new 'simplified' API, which was started in libpng-1.5.7beta02
3796    but later deleted from libpng-1.5.7beta05.
3797  Added example programs for the new 'simplified' API.
3798  Added ANSI-C (C90) headers and require them, and take advantage of the
3799    change. Also fixed some of the projects/* and contrib/* files that needed
3800    updates for libpng16 and the move of pngvalid.c.
3801    With this change the required ANSI-C header files are assumed to exist: the
3802    implementation must provide float.h, limits.h, stdarg.h and stddef.h and
3803    libpng relies on limits.h and stddef.h existing and behaving as defined
3804    (the other two required headers aren't used).  Non-ANSI systems that don't
3805    have stddef.h or limits.h will have to provide an appropriate fake
3806    containing the relevant types and #defines.
3807  Dropped support for 16-bit platforms. The use of FAR/far has been eliminated
3808    and the definition of png_alloc_size_t is now controlled by a flag so
3809    that 'small size_t' systems can select it if necessary.  Libpng 1.6 may
3810    not currently work on such systems -- it seems likely that it will
3811    ask 'malloc' for more than 65535 bytes with any image that has a
3812    sufficiently large row size (rather than simply failing to read such
3813    images).
3814  New tools directory containing tools used to generate libpng code.
3815  Fixed race conditions in parallel make builds. With higher degrees of
3816    parallelism during 'make' the use of the same temporary file names such
3817    as 'dfn*' can result in a race where a temporary file from one arm of the
3818    build is deleted or overwritten in another arm.  This changes the
3819    temporary files for suffix rules to always use $* and ensures that the
3820    non-suffix rules use unique file names.
3821
3822Version 1.6.0beta02 [December 21, 2011]
3823  Correct configure builds where build and source directories are separate.
3824    The include path of 'config.h' was erroneously made relative in pngvalid.c
3825    in libpng 1.5.7.
3826
3827Version 1.6.0beta03 [December 22, 2011]
3828  Start-up code size improvements, error handler flexibility. These changes
3829    alter how the tricky allocation of the initial png_struct and png_info
3830    structures are handled. png_info is now handled in pretty much the same
3831    way as everything else, except that the allocations handle NULL return
3832    silently.  png_struct is changed in a similar way on allocation and on
3833    deallocation a 'safety' error handler is put in place (which should never
3834    be required).  The error handler itself is changed to permit mismatches
3835    in the application and libpng error buffer size; however, this means a
3836    silent change to the API to return the jmp_buf if the size doesn't match
3837    the size from the libpng compilation; libpng now allocates the memory and
3838    this may fail.  Overall these changes result in slight code size
3839    reductions; however, this is a reduction in code that is always executed
3840    so is particularly valuable.  Overall on a 64-bit system the libpng DLL
3841    decreases in code size by 1733 bytes.  pngerror.o increases in size by
3842    about 465 bytes because of the new functionality.
3843  Added png_convert_to_rfc1123_buffer() and deprecated png_convert_to_rfc1123()
3844    to avoid including a spurious buffer in the png_struct.
3845
3846Version 1.6.0beta04 [December 30, 2011]
3847  Regenerated configure scripts with automake-1.11.2
3848  Eliminated png_info_destroy(). It is now used only in png.c and only calls
3849    one other internal function and memset().
3850  Enabled png_get_sCAL_fixed() if floating point APIs are enabled. Previously
3851    it was disabled whenever internal fixed point arithmetic was selected,
3852    which meant it didn't exist even on systems where FP was available but not
3853    preferred.
3854  Added pngvalid.c compile time checks for const APIs.
3855  Implemented 'restrict' for png_info and png_struct. Because of the way
3856    libpng works both png_info and png_struct are always accessed via a
3857    single pointer.  This means adding C99 'restrict' to the pointer gives
3858    the compiler some opportunity to optimize the code.  This change allows
3859    that.
3860  Moved AC_MSG_CHECKING([if libraries can be versioned]) later to the proper
3861    location in configure.ac (Gilles Espinasse).
3862  Changed png_memcpy to C assignment where appropriate. Changed all those
3863    uses of png_memcpy that were doing a simple assignment to assignments
3864    (all those cases where the thing being copied is a non-array C L-value).
3865  Added some error checking to png_set_*() routines.
3866  Removed the reference to the non-exported function png_memcpy() from
3867    example.c.
3868  Fixed the Visual C 64-bit build - it requires jmp_buf to be aligned, but
3869    it had become misaligned.
3870  Revised contrib/pngminus/pnm2png.c to avoid warnings when png_uint_32
3871    and unsigned long are of different sizes.
3872
3873Version 1.6.0beta05 [January 15, 2012]
3874  Updated manual with description of the simplified API (copied from png.h)
3875  Fix bug in pngerror.c: some long warnings were being improperly truncated
3876    (CVE-2011-3464, bug introduced in libpng-1.5.3beta05).
3877
3878Version 1.6.0beta06 [January 24, 2012]
3879  Added palette support to the simplified APIs. This commit
3880    changes some of the macro definitions in png.h, app code
3881    may need corresponding changes.
3882  Increased the formatted warning buffer to 192 bytes.
3883  Added color-map support to simplified API. This is an initial version for
3884    review; the documentation has not yet been updated.
3885  Fixed Min/GW uninstall to remove libpng.dll.a
3886
3887Version 1.6.0beta07 [January 28, 2012]
3888  Eliminated Intel icc/icl compiler warnings. The Intel (GCC derived)
3889    compiler issues slightly different warnings from those issued by the
3890    current vesions of GCC. This eliminates those warnings by
3891    adding/removing casts and small code rewrites.
3892  Updated configure.ac from autoupdate: added --enable-werror option.
3893    Also some layout regularization and removal of introduced tab characters
3894    (replaced with 3-character indentation).  Obsolete macros identified by
3895    autoupdate have been removed; the replacements are all in 2.59 so
3896    the pre-req hasn't been changed.  --enable-werror checks for support
3897    for -Werror (or the given argument) in the compiler.  This mimics the
3898    gcc configure option by allowing -Werror to be turned on safely; without
3899    the option the tests written in configure itself fail compilation because
3900    they cause compiler warnings.
3901  Rewrote autogen.sh to run autoreconf instead of running tools one-by-one.
3902  Conditionalize the install rules for MINGW and CYGWIN in CMakeLists.txt and
3903    set CMAKE_LIBRARY_OUTPUT_DIRECTORY to "lib" on all platforms (C. Yapp).
3904  Freeze libtool files in the 'scripts' directory. This version of autogen.sh
3905    attempts to dissuade people from running it when it is not, or should not,
3906    be necessary.  In fact, autogen.sh does not work when run in a libpng
3907    directory extracted from a tar distribution anymore. You must run it in
3908    a GIT clone instead.
3909  Added two images to contrib/pngsuite (1-bit and 2-bit transparent grayscale),
3910    and renamed three whose names were inconsistent with those in
3911    pngsuite/README.txt.
3912
3913Version 1.6.0beta08 [February 1, 2012]
3914  Fixed Image::colormap misalignment in pngstest.c
3915  Check libtool/libtoolize version number (2.4.2) in configure.ac
3916  Divide test-pngstest.sh into separate pngstest runs for basic and
3917    transparent images.
3918  Moved automake options to AM_INIT_AUTOMAKE in configure.ac
3919  Added color-tests, silent-rules (Not yet implemented in Makefile.am) and
3920    version checking to configure.ac
3921  Improved pngstest speed by not doing redundant tests and add const to
3922    the background parameter of png_image_finish_read. The --background
3923    option is now done automagically only when required, so that commandline
3924    option no longer exists.
3925  Cleaned up pngpriv.h to consistently declare all functions and data.
3926    Also eliminated PNG_CONST_DATA, which is apparently not needed but we
3927    can't be sure until it is gone.
3928  Added symbol prefixing that allows all the libpng external symbols
3929    to be prefixed (suggested by Reuben Hawkins).
3930  Updated "ftbb*.png" list in the owatcom and vstudio projects.
3931  Fixed 'prefix' builds on clean systems. The generation of pngprefix.h
3932    should not require itself.
3933  Updated INSTALL to explain that autogen.sh must be run in a GIT clone,
3934    not in a libpng directory extracted from a tar distribution.
3935
3936Version 1.6.0beta09 [February 1, 2012]
3937  Reverted the prebuilt configure files to libpng-1.6.0beta05 condition.
3938
3939Version 1.6.0beta10 [February 3, 2012]
3940  Added Z_SOLO for zlib-1.2.6+ and correct pngstest tests
3941  Updated list of test images in CMakeLists.txt
3942  Updated the prebuilt configure files to current condition.
3943  Revised INSTALL information about autogen.sh; it works in tar distributions.
3944
3945Version 1.6.0beta11 [February 16, 2012]
3946  Fix character count in pngstest command in projects/owatcom/pngstest.tgt
3947  Revised test-pngstest.sh to report PASS/FAIL for each image.
3948  Updated documentation about the simplified API.
3949  Corrected estimate of error in libpng png_set_rgb_to_gray API.  The API is
3950    extremely inaccurate for sRGB conversions because it uses an 8-bit
3951    intermediate linear value and it does not use the sRGB transform, so it
3952    suffers from the known instability in gamma transforms for values close
3953    to 0 (see Poynton).  The net result is that the calculation has a maximum
3954    error of 14.99/255; 0.5/255^(1/2.2).  pngstest now uses 15 for the
3955    permitted 8-bit error. This may still not be enough because of arithmetic
3956    error.
3957  Removed some unused arrays (with #ifdef) from png_read_push_finish_row().
3958  Fixed a memory overwrite bug in simplified read of RGB PNG with
3959    non-linear gamma Also bugs in the error checking in pngread.c and changed
3960    quite a lot of the checks in pngstest.c to be correct; either correctly
3961    written or not over-optimistic.  The pngstest changes are insufficient to
3962    allow all possible RGB transforms to be passed; pngstest cmppixel needs
3963    to be rewritten to make it clearer which errors it allows and then changed
3964    to permit known inaccuracies.
3965  Removed tests for no-longer-used *_EMPTY_PLTE_SUPPORTED from pngstruct.h
3966  Fixed fixed/float API export conditionals. 1) If FIXED_POINT or
3967    FLOATING_POINT options were switched off, png.h ended up with lone ';'
3968    characters.  This is not valid ANSI-C outside a function.  The ';'
3969    characters have been moved inside the definition of PNG_FP_EXPORT and
3970    PNG_FIXED_EXPORT. 2) If either option was switched off, the declaration
3971    of the corresponding functions were completely omitted, even though some
3972    of them are still used internally.  The result is still valid, but
3973    produces warnings from gcc with some warning options (including -Wall). The
3974    fix is to cause png.h to declare the functions with PNG_INTERNAL_FUNCTION
3975    when png.h is included from pngpriv.h.
3976  Check for invalid palette index while reading paletted PNG.  When one is
3977    found, issue a warning and increase png_ptr->num_palette accordingly.
3978    Apps are responsible for checking to see if that happened.
3979
3980Version 1.6.0beta12 [February 18, 2012]
3981  Do not increase num_palette on invalid_index.
3982  Relocated check for invalid palette index to pngrtran.c, after unpacking
3983    the sub-8-bit pixels.
3984  Fixed CVE-2011-3026 buffer overrun bug.  This bug was introduced when
3985    iCCP chunk support was added at libpng-1.0.6. Deal more correctly with the
3986    test on iCCP chunk length. Also removed spurious casts that may hide
3987    problems on 16-bit systems.
3988
3989Version 1.6.0beta13 [February 24, 2012]
3990  Eliminated redundant png_push_read_tEXt|zTXt|iTXt|unknown code from
3991    pngpread.c and use the sequential png_handle_tEXt, etc., in pngrutil.c;
3992    now that png_ptr->buffer is inaccessible to applications, the special
3993    handling is no longer useful.
3994  Added PNG_SAFE_LIMITS feature to pnglibconf.dfa, pngpriv.h, and new
3995    pngusr.dfa to reset the user limits to safe ones if PNG_SAFE_LIMITS is
3996    defined.  To enable, use "CPPFLAGS=-DPNG_SAFE_LIMITS_SUPPORTED=1" on the
3997    configure command or put #define PNG_SAFE_LIMITS_SUPPORTED in
3998    pnglibconf.h.prebuilt and pnglibconf.h.
3999
4000Version 1.6.0beta14 [February 27, 2012]
4001  Added information about the new limits in the manual.
4002  Updated Makefile.in
4003
4004Version 1.6.0beta15 [March 2, 2012]
4005  Removed unused "current_text" members of png_struct and the png_free()
4006    of png_ptr->current_text from pngread.c
4007  Rewrote pngstest.c for substantial speed improvement.
4008  Fixed transparent pixel and 16-bit rgb tests in pngstest and removed a
4009    spurious check in pngwrite.c
4010  Added PNG_IMAGE_FLAG_FAST for the benefit of applications that store
4011    intermediate files, or intermediate in-memory data, while processing
4012    image data with the simplified API.  The option makes the files larger
4013    but faster to write and read.  pngstest now uses this by default; this
4014    can be disabled with the --slow option.
4015  Improved pngstest fine tuning of error numbers, new test file generator.
4016    The generator generates images that test the full range of sample values,
4017    allow the error numbers in pngstest to be tuned and checked.  makepng
4018    also allows generation of images with extra chunks, although this is
4019    still work-in-progress.
4020  Added check for invalid palette index while reading.
4021  Fixed some bugs in ICC profile writing. The code should now accept
4022    all potentially valid ICC profiles and reject obviously invalid ones.
4023    It now uses png_error() to do so rather than casually writing a PNG
4024    without the necessary color data.
4025  Removed whitespace from the end of lines in all source files and scripts.
4026
4027Version 1.6.0beta16 [March 6, 2012]
4028  Relocated palette-index checking function from pngrutil.c to pngtrans.c
4029  Added palette-index checking while writing.
4030  Changed png_inflate() and calling routines to avoid overflow problems.
4031    This is an intermediate check-in that solves the immediate problems and
4032    introduces one performance improvement (avoiding a copy via png_ptr->zbuf.)
4033    Further changes will be made to make ICC profile handling more secure.
4034  Fixed build warnings (MSVC, GCC, GCC v3). Cygwin GCC with default options
4035    declares 'index' as a global, causing a warning if it is used as a local
4036    variable.  GCC 64-bit warns about assigning a (size_t) (unsigned 64-bit)
4037    to an (int) (signed 32-bit).  MSVC, however, warns about using the
4038    unary '-' operator on an unsigned value (even though it is well defined
4039    by ANSI-C to be ~x+1).  The padding calculation was changed to use a
4040    different method.  Removed the tests on png_ptr->pass.
4041  Added contrib/libtests/tarith.c to test internal arithmetic functions from
4042    png.c. This is a libpng maintainer program used to validate changes to the
4043    internal arithmetic functions.
4044  Made read 'inflate' handling like write 'deflate' handling. The read
4045    code now claims and releases png_ptr->zstream, like the write code.
4046    The bug whereby the progressive reader failed to release the zstream
4047    is now fixed, all initialization is delayed, and the code checks for
4048    changed parameters on deflate rather than always calling
4049    deflatedEnd/deflateInit.
4050  Validate the zTXt strings in pngvalid.
4051  Added code to validate the windowBits value passed to deflateInit2().
4052    If the call to deflateInit2() is wrong a png_warning will be issued
4053    (in fact this is harmless, but the PNG data produced may be sub-optimal).
4054
4055Version 1.6.0beta17 [March 10, 2012]
4056  Fixed PNG_LIBPNG_BUILD_BASE_TYPE definition. 
4057  Reject all iCCP chunks after the first, even if the first one is invalid.
4058  Deflate/inflate was reworked to move common zlib calls into single
4059    functions [rw]util.c.  A new shared keyword check routine was also added
4060    and the 'zbuf' is no longer allocated on progressive read.  It is now
4061    possible to call png_inflate() incrementally.  A warning is no longer
4062    issued if the language tag or translated keyword in the iTXt chunk
4063    has zero length.
4064  If benign errors are disabled use maximum window on ancilliary inflate.
4065    This works round a bug introduced in 1.5.4 where compressed ancillary
4066    chunks could end up with a too-small windowBits value in the deflate
4067    header.
4068
4069Version 1.6.0beta18 [March 16, 2012]
4070  Issue a png_benign_error() instead of png_warning() about bad palette index.
4071  In pngtest, treat benign errors as errors if "-strict" is present.
4072  Fixed an off-by-one error in the palette index checking function.
4073  Fixed a compiler warning under Cygwin (Windows-7, 32-bit system)
4074  Revised example.c to put text strings in a temporary character array
4075    instead of directly assigning string constants to png_textp members.
4076    This avoids compiler warnings when -Wwrite-strings is enabled.
4077  Added output flushing to aid debugging under Visual Studio. Unfortunately
4078    this is necessary because the VS2010 output window otherwise simply loses
4079    the error messages on error (they weren't flushed to the window before
4080    the process exited, apparently!)
4081  Added configuration support for benign errors and changed the read
4082    default. Also changed some warnings in the iCCP and sRGB handling
4083    from to benign errors. Configuration now makes read benign
4084    errors warnings and write benign errors to errors by default (thus
4085    changing the behavior on read).  The simplified API always forces
4086    read benign errors to warnings (regardless of the system default, unless
4087    this is disabled in which case the simplified API can't be built.)
4088
4089Version 1.6.0beta19 [March 18, 2012]
4090  Work around for duplicate row start calls; added warning messages.
4091    This turns on PNG_FLAG_DETECT_UNINITIALIZED to detect app code that
4092    fails to call one of the 'start' routines (not enabled in libpng-1.5
4093    because it is technically an API change, since it did normally work
4094    before.)  It also makes duplicate calls to png_read_start_row (an
4095    internal function called at the start of the image read) benign, as
4096    they were before changes to use png_inflate_claim. Somehow webkit is
4097    causing this to happen; this is probably a mis-feature in the zlib
4098    changes so this commit is only a work-round.
4099  Removed erroneous setting of DETECT_UNINITIALIZED and added more
4100    checks. The code now does a png_error if an attempt is made to do the
4101    row initialization twice; this is an application error and it has
4102    serious consequences because the transform data in png_struct is
4103    changed by each call.
4104  Added application error reporting and added chunk names to read
4105    benign errors; also added --strict to pngstest - not enabled
4106    yet because a warning is produced.
4107  Avoid the double gamma correction warning in the simplified API.
4108    This allows the --strict option to pass in the pngstest checks
4109
4110Version 1.6.0beta20 [March 29, 2012]
4111  Changed chunk handler warnings into benign errors, incrementally load iCCP
4112  Added checksum-icc.c to contrib/tools
4113  Prevent PNG_EXPAND+PNG_SHIFT doing the shift twice.
4114  Recognize known sRGB ICC profiles while reading; prefer writing the
4115    iCCP profile over writing the sRGB chunk, controlled by the
4116    PNG_sRGB_PROFILE_CHECKS option.
4117  Revised png_set_text_2() to avoid potential memory corruption (fixes
4118    CVE-2011-3048, also known as CVE-2012-3425).
4119
4120Version 1.6.0beta21 [April 27, 2012]
4121  Revised scripts/makefile.darwin: use system zlib; remove quotes around
4122    architecture list; add missing ppc architecture; add architecture options
4123    to shared library link; don't try to create a shared lib based on missing
4124    RELEASE variable.
4125  Enable png_set_check_for_invalid_index() for both read and write.
4126  Removed #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED in pngpriv.h around
4127    declaration of png_handle_unknown().
4128  Added -lssp_nonshared in a comment in scripts/makefile.freebsd
4129    and changed deprecated NOOBJ and NOPROFILE to NO_OBJ and NO_PROFILE.
4130
4131Version 1.6.0beta22 [May 23, 2012]
4132  Removed need for -Wno-cast-align with clang.  clang correctly warns on
4133    alignment increasing pointer casts when -Wcast-align is passed. This
4134    fixes the cases that clang warns about either by eliminating the
4135    casts from png_bytep to png_uint_16p (pngread.c), or, for pngrutil.c
4136    where the cast is previously verified or pngstest.c where it is OK, by
4137    introducing new png_aligncast macros to do the cast in a way that clang
4138    accepts.
4139
4140Version 1.6.0beta23 [June 6, 2012]
4141  Revised CMakeLists.txt to not attempt to make a symlink under mingw.
4142  Made fixes for new optimization warnings from gcc 4.7.0. The compiler
4143    performs an optimization which is safe; however it then warns about it.
4144    Changing the type of 'palette_number' in pngvalid.c removes the warning.
4145  Do not depend upon a GCC feature macro being available for use in generating
4146    the linker mapfile symbol prefix.
4147  Improved performance of new do_check_palette_indexes() function (only
4148    update the value when it actually increases, move test for whether
4149    the check is wanted out of the function.
4150
4151Version 1.6.0beta24 [June 7, 2012]
4152  Don't check palette indexes if num_palette is 0 (as it can be in MNG files).
4153
4154Version 1.6.0beta25 [June 16, 2012]
4155  Revised png_set_keep_unknown_chunks() so num_chunks < 0 means ignore all
4156    unknown chunks and all known chunks except for IHDR, PLTE, tRNS, IDAT,
4157    and IEND.  Previously it only meant ignore all unknown chunks, the
4158    same as num_chunks == 0. Revised png_image_skip_unused_chunks() to
4159    provide a list of chunks to be processed instead of a list of chunks to
4160    ignore.  Revised contrib/gregbook/readpng2.c accordingly.
4161
4162Version 1.6.0beta26 [July 10, 2012]
4163  Removed scripts/makefile.cegcc from the *.zip and *.7z distributions; it
4164    depends on configure, which is not included in those archives.
4165  Moved scripts/chkfmt to contrib/tools.
4166  Changed "a+w" to "u+w" in Makefile.in to fix CVE-2012-3386.
4167
4168Version 1.6.0beta27 [August 11, 2012]
4169  Do not compile PNG_DEPRECATED, PNG_ALLOC and PNG_PRIVATE when __GNUC__ < 3.
4170  Do not use __restrict when GNUC is <= 3.1
4171  Removed references to png_zalloc() and png_zfree() from the manual.
4172  Fixed configurations where floating point is completely disabled.  Because
4173    of the changes to support symbol prefixing PNG_INTERNAL_FUNCTION declares
4174    floating point APIs during libpng builds even if they are completely
4175    disabled. This requires the png floating point types (png_double*) to be
4176    declared even though the functions are never actually defined.  This
4177    change provides a dummy definition so that the declarations work, yet any
4178    implementation will fail to compile because of an incomplete type.
4179  Re-eliminated the use of strcpy() in pngtest.c.  An unncessary use of
4180    strcpy() was accidentally re-introduced in libpng16; this change replaces
4181    it with strncpy().
4182  Eliminated use of png_sizeof(); use sizeof() instead.
4183  Use a consistent style for (sizeof type) and (sizeof (array))
4184  Cleanup of png_set_filler().  This function does very different things on
4185    read and write.  In libpng 1.6 the two cases can be distinguished and
4186    considerable code cleanup, and extra error checking, is possible.  This
4187    makes calls on the write side that have no effect be ignored with a
4188    png_app_error(), which can be disabled in the app using
4189    png_set_benign_errors(), and removes the spurious use of usr_channels
4190    on the read side.
4191  Insist on autotools 1.12.1 for git builds because there are security issues
4192    with 1.12 and insisting on anything less would allow 1.12 to be used.
4193  Removed info_ptr->signature[8] from WRITE-only builds.
4194  Add some conditions for compiling png_fixed().  This is a small function
4195    but it requires "-lm" on some platforms.
4196  Cause pngtest --strict to fail on any warning from libpng (not just errors)
4197    and cause it not to fail at the comparison step if libpng lacks support
4198    for writing chunks that it reads from the input (currently only implemented
4199    for compressed text chunks).
4200  Make all three "make check" test programs work without READ or WRITE support.
4201    Now "make check" will succeed even if libpng is compiled with -DPNG_NO_READ
4202    or -DPNG_NO_WRITE.  The tests performed are reduced, but the basic reading
4203    and writing of a PNG file is always tested by one or more of the tests.
4204  Consistently use strlen(), memset(), memcpy(), and memcmp() instead of the
4205    png_strlen(), png_memset(), png_memcpy(), and png_memcmp() macros.
4206  Removed the png_sizeof(), png_strlen(), png_memset(), png_memcpy(), and
4207    png_memcmp() macros.
4208  Work around gcc 3.x and Microsoft Visual Studio 2010 complaints. Both object
4209    to the split initialization of num_chunks.
4210
4211Version 1.6.0beta28 [August 29, 2012]
4212  Unknown handling fixes and clean up. This adds more correct option
4213    control of the unknown handling, corrects the pre-existing bug where
4214    the per-chunk 'keep' setting is ignored and makes it possible to skip
4215    IDAT chunks in the sequential reader (broken in earlier 1.6 versions).
4216    There is a new test program, test-unknown.c, which is a work in progress
4217    (not currently part of the test suite).  Comments in the header files now
4218    explain how the unknown handling works.
4219  Allow fine grain control of unknown chunk APIs. This change allows
4220    png_set_keep_unknown_chunks() to be turned off if not required and causes
4221    both read and write to behave appropriately (on read this is only possible
4222    if the user callback is used to handle unknown chunks).  The change
4223    also removes the support for storing unknown chunks in the info_struct
4224    if the only unknown handling enabled is via the callback, allowing libpng
4225    to be configured with callback reading and none of the unnecessary code.
4226  Corrected fix for unknown handling in pngtest. This reinstates the
4227    libpng handling of unknown chunks other than vpAg and sTER (including
4228    unsafe-to-copy chunks which were dropped before) and eliminates the
4229    repositioning of vpAg and sTER in pngtest.png by changing pngtest.png
4230    (so the chunks are where libpng would put them).
4231  Added "tunknown" test and corrected a logic error in png_handle_unknown()
4232    when SAVE support is absent.  Moved the shell test scripts for
4233    contrib/libtests from the libpng top directory to contrib/libtests.
4234    png_handle_unknown() must always read or skip the chunk, if
4235    SAVE_UNKNOWN_CHUNKS is turned off *and* the application does not set
4236    a user callback an unknown chunk will not be read, leading to a read
4237    error, which was revealed by the "tunknown" test.
4238  Cleaned up and corrected ICC profile handling.
4239    contrib/libtests/makepng: corrected 'rgb' and 'gray' cases.  profile_error
4240    messages could be truncated; made a correct buffer size calculation and
4241    adjusted pngerror.c appropriately. png_icc_check_* checking improved;
4242    changed the functions to receive the correct color type of the PNG on read
4243    or write and check that it matches the color space of the profile (despite
4244    what the comments said before, there is danger in assuming the app will
4245    cope correctly with an RGB profile on a grayscale image and, since it
4246    violates the PNG spec, allowing it is certain to produce inconsistent
4247    app behavior and might even cause app crashes.) Check that profiles
4248    contain the tags needed to process the PNG (tags all required by the ICC
4249    spec). Removed unused PNG_STATIC from pngpriv.h.
4250
4251Version 1.6.0beta29 [September 4, 2012]
4252  Fixed the simplified API example programs to add the *colormap parameter
4253    to several of he API and improved the error message if the version field
4254    is not set.
4255  Added contrib/examples/* to the *.zip and *.7z distributions.
4256  Updated simplified API synopses and description of the png_image structure
4257    in the manual.
4258  Made makepng and pngtest produce identical PNGs, add "--relaxed" option
4259    to pngtest. The "--relaxed" option turns off the benign errors that are
4260    enabled by default in pre-RC builds. makepng can now write ICC profiles
4261    where the length has not been extended to a multiple of 4, and pngtest
4262    now intercepts all libpng errors, allowing the previously-introduced
4263    "--strict test" on no warnings to actually work.
4264  Improved ICC profile handling including cHRM chunk generation and fixed
4265    Cygwin+MSVC build errors. The ICC profile handling now includes more
4266    checking.  Several errors that caused rejection of the profile are now
4267    handled with a warning in such a way that the invalid profiles will be
4268    read by default in release (but not pre-RC) builds but will not be
4269    written by default.  The easy part of handling the cHRM chunk is written,
4270    where the ICC profile contains the required data.  The more difficult
4271    part plus guessing a gAMA value requires code to pass selected RGB values
4272    through the profile.
4273
4274Version 1.6.0beta30 [October 24, 2012]
4275  Changed ICC profile matrix/vector types to not depend on array type rules.
4276    By the ANSI-C standard the new types should be identical to the previous
4277    versions, and all known versions of gcc tested with the previous versions
4278    except for GCC-4.2.1 work with this version.  The change makes the ANSI-C
4279    rule that const applied to an array of elements applies instead to the
4280    elements in the array moot by explicitly applying const to the base
4281    elements of the png_icc_matrix and png_icc_vector types. The accidental
4282    (harmless) 'const' previously applied to the parameters of two of the
4283    functions have also been removed.
4284  Added a work around for GCC 4.2 optimization bug.
4285  Marked the broken (bad white point) original HP sRGB profiles correctly and
4286    correct comments.
4287  Added -DZ_SOLO to contrib/pngminim/*/makefile to work with zlib-1.2.7
4288  Use /MDd for vstudio debug builds. Also added pngunkown to the vstudio
4289    builds, fixed build errors and corrected a minor exit code error in
4290    pngvalid if the 'touch' file name is invalid.
4291  Add updated WARNING file to projects/vstudio from libpng 1.5/vstudio
4292  Fixed build when using #define PNG_NO_READ_GAMMA in png_do_compose() in
4293    pngrtran.c (Domani Hannes).
4294
4295Version 1.6.0beta31 [November 1, 2012]
4296  Undid the erroneous change to vstudio/pngvalid build in libpng-1.6.0beta30.
4297  Made pngvalid so that it will build outside the libpng source tree.
4298  Made builds -DPNG_NO_READ_GAMMA compile (the unit tests still fail).
4299  Made PNG_NO_READ_GAMMA switch off interfaces that depend on READ_GAMMA.
4300    Prior to 1.6.0 switching off READ_GAMMA did unpredictable things to the
4301    interfaces that use it (specifically, png_do_background in 1.4 would
4302    simply display composite for grayscale images but do composition
4303    with the incorrect arithmetic for color ones). In 1.6 the semantic
4304    of -DPNG_NO_READ_GAMMA is changed to simply disable any interface that
4305    depends on it; this obliges people who set it to consider whether they
4306    really want it off if they happen to use any of the interfaces in
4307    question (typically most users who disable it won't).
4308  Fixed GUIDs in projects/vstudio. Some were duplicated or missing,
4309    resulting in VS2010 having to update the files.
4310  Removed non-working ICC profile support code that was mostly added to
4311    libpng-1.6.0beta29 and beta30. There was too much code for too little
4312    gain; implementing full ICC color correction may be desireable but is left
4313    up to applications.
4314
4315Version 1.6.0beta32 [November 25, 2012]
4316  Fixed an intermittent SEGV in pngstest due to an uninitialized array element.
4317  Added the ability for contrib/libtests/makepng.c to make a PNG with just one
4318    color. This is useful for debugging pngstest color inaccuracy reports.
4319  Fixed error checking in the simplified write API (Olaf van der Spek)
4320  Made png_user_version_check() ok to use with libpng version 1.10.x and later.
4321
4322Version 1.6.0beta33 [December 15, 2012]
4323  Fixed typo in png.c (PNG_SET_CHUNK_MALLOC_MAX should be PNG_CHUNK_MALLOC_MAX)
4324    that causes the MALLOC_MAX limit not to work (John Bowler)
4325  Change png_warning() to png_app_error() in pngwrite.c and comment the
4326    fall-through condition.
4327  Change png_warning() to png_app_warning() in png_write_tRNS().
4328  Rearranged the ARM-NEON optimizations: Isolated the machine specific code
4329    to the hardware subdirectory and added comments to pngrutil.c so that
4330    implementors of other optimizations know what to do.
4331  Fixed cases of unquoted DESTDIR in Makefile.am
4332  Rebuilt Makefile.in, etc., with autoconf-2.69 and automake-1.12.5.
4333
4334Version 1.6.0beta34 [December 19, 2012]
4335  Cleaned up whitespace in the synopsis portion of the manpage "libpng.3"
4336  Disassembled the version number in scripts/options.awk (necessary for
4337    building on SunOs).
4338
4339Version 1.6.0beta35 [December 23, 2012]
4340  Made default Zlib compression settings be configurable. This adds #defines to
4341    pnglibconf.h to control the defaults.
4342  Fixed Windows build issues, enabled ARM compilation. Various warnings issued
4343    by earlier versions of GCC fixed for Cygwin and Min/GW (which both use old
4344    GCCs.) ARM support is enabled by default in zlib.props (unsupported by
4345    Microsoft) and ARM compilation is made possible by deleting the check for
4346    x86. The test programs cannot be run because they are not signed.
4347
4348Version 1.6.0beta36 [January 2, 2013]
4349  Discontinued distributing libpng-1.x.x.tar.bz2.
4350  Discontinued distributing libpng-1.7.0-1.6.0-diff.txt and similar.
4351  Rebuilt configure with autoconf-2.69 (inadvertently not done in beta33)
4352  Fixed 'make distcheck' on SUN OS - libpng.so was not being removed
4353
4354Version 1.6.0beta37 [January 10, 2013]
4355  Fixed conceivable but difficult to repro overflow. Also added two test
4356    programs to generate and test a PNG which should have the problem.
4357
4358Version 1.6.0beta39 [January 19, 2013]
4359  Again corrected attempt at overflow detection in png_set_unknown_chunks()
4360  (CVE-2013-7353).  Added overflow detection in png_set_sPLT() and
4361  png_set_text_2() (CVE-2013-7354).
4362
4363Version 1.6.0beta40 [January 20, 2013]
4364  Use consistent handling of overflows in text, sPLT and unknown png_set_* APIs
4365
4366Version 1.6.0rc01 [January 26, 2013]
4367  No changes.
4368
4369Version 1.6.0rc02 [February 4, 2013]
4370  Added png_get_palette_max() function.
4371
4372Version 1.6.0rc03 [February 5, 2013]
4373  Fixed the png_get_palette_max API.
4374
4375Version 1.6.0rc04 [February 7, 2013]
4376  Turn serial tests back on (recently turned off by autotools upgrade).
4377
4378Version 1.6.0rc05 [February 8, 2013]
4379  Update manual about png_get_palette_max().
4380
4381Version 1.6.0rc06 [February 9, 2013]
4382  Fixed missing dependency in --prefix builds The intermediate
4383    internal 'prefix.h' file can only be generated correctly after
4384    pnglibconf.h, however the dependency was not in Makefile.am.  The
4385    symptoms are unpredictable depending on the order make chooses to
4386    build pngprefix.h and pnglibconf.h, often the error goes unnoticed
4387    because there is a system pnglibconf.h to use instead.
4388
4389Version 1.6.0rc07 [February 10, 2013]
4390  Enclosed the new png_get_palette_max in #ifdef PNG_GET_PALETTE_MAX_SUPPORTED
4391    block, and revised pnglibconf.h and pnglibconf.h.prebuilt accordingly.
4392
4393Version 1.6.0rc08 [February 10, 2013]
4394  Fix typo in png.h #ifdef
4395
4396Version 1.6.0 [February 14, 2013]
4397  No changes.
4398
4399Version 1.6.1beta01 [February 16, 2013]
4400  Made symbol prefixing work with the ARM neon optimizations. Also allow
4401    pngpriv.h to be included for preprocessor definitions only, so it can
4402    be used in non-C/C++ files. Back ported from libpng 1.7.
4403  Made sRGB check numbers consistent.
4404  Ported libpng 1.5 options.awk/dfn file handling to 1.6, fixed one bug.
4405  Removed cc -E workround, corrected png_get_palette_max API Tested on
4406    SUN OS cc 5.9, which demonstrates the tokenization problem previously
4407    avoided by using /lib/cpp.  Since all .dfn output is now protected in
4408    double quotes unless it is to be macro substituted the fix should
4409    work everywhere.
4410  Enabled parallel tests - back ported from libpng-1.7.
4411  scripts/pnglibconf.dfa formatting improvements back ported from libpng17.
4412  Fixed a race condition in the creation of the build 'scripts' directory
4413    while building with a parallel make.
4414  Use approved/supported Android method to check for NEON, use Linux/POSIX
4415    1003.1 API to check /proc/self/auxv avoiding buffer allocation and other
4416    library calls (ported from libpng15).
4417
4418Version 1.6.1beta02 [February 19, 2013]
4419  Use parentheses more consistently in "#if defined(MACRO)" tests.
4420  Folded long lines.
4421  Reenabled code to allow zero length PLTE chunks for MNG.
4422
4423Version 1.6.1beta03 [February 22, 2013]
4424  Fixed ALIGNED_MEMORY support.
4425  Added a new configure option:
4426    --enable-arm-neon=always will stop the run-time checks. New checks
4427    within arm/arm_init.c will cause the code not to be compiled unless
4428    __ARM_NEON__ is set. This should make it fail safe (if someone asks
4429    for it on then the build will fail if it can't be done.)
4430  Updated the INSTALL document.
4431
4432Version 1.6.1beta04 [February 27, 2013]
4433  Revised INSTALL to recommend using CPPFLAGS instead of INCLUDES.
4434  Revised scripts/makefile.freebsd to respect ZLIBLIB and ZLIBINC.
4435  Revised scripts/dfn.awk to work with the buggy MSYS awk that has trouble
4436    with CRLF line endings.
4437
4438Version 1.6.1beta05 [March 1, 2013]
4439  Avoid a possible memory leak in contrib/gregbook/readpng.c
4440
4441Version 1.6.1beta06 [March 4, 2013]
4442  Better documentation of unknown handling API interactions.
4443  Corrected Android builds and corrected libpng.vers with symbol
4444    prefixing.  It also makes those tests compile and link on Android.
4445  Added an API png_set_option() to set optimization options externally,
4446    providing an alternative and general solution for the non-portable
4447    run-time tests used by the ARM Neon code, using the PNG_ARM_NEON option.
4448  The order of settings vs options in pnglibconf.h is reversed to allow
4449    settings to depend on options and options can now set (or override) the
4450    defaults for settings.
4451
4452Version 1.6.1beta07 [March 7, 2013]
4453  Corrected simplified API default gamma for color-mapped output, added
4454    a flag to change default. In 1.6.0 when the simplified API was used
4455    to produce color-mapped output from an input image with no gamma
4456    information the gamma assumed for the input could be different from
4457    that assumed for non-color-mapped output.  In particular 16-bit depth
4458    input files were assumed to be sRGB encoded, whereas in the 'direct'
4459    case they were assumed to have linear data.  This was an error.  The
4460    fix makes the simplified API treat all input files the same way and
4461    adds a new flag to the png_image::flags member to allow the
4462    application/user to specify that 16-bit files contain sRGB data
4463    rather than the default linear.
4464  Fixed bugs in the pngpixel and makepng test programs.
4465
4466Version 1.6.1beta08 [March 7, 2013]
4467  Fixed CMakelists.txt to allow building a single variant of the library
4468    (Claudio Bley):
4469  Introduced a PNG_LIB_TARGETS variable that lists all activated library
4470    targets.  It is an error if this variable ends up empty, ie. you have
4471    to build at least one library variant.
4472  Made the *_COPY targets only depend on library targets actually being build.
4473  Use PNG_LIB_TARGETS to unify a code path.
4474  Changed the CREATE_SYMLINK macro to expect the full path to a file as the
4475    first argument. When symlinking the filename component of that path is
4476    determined and used as the link target.
4477  Use copy_if_different in the CREATE_SYMLINK macro.
4478
4479Version 1.6.1beta09 [March 13, 2013]
4480  Eliminated two warnings from the Intel C compiler. The warnings are
4481    technically valid, although a reasonable treatment of division would
4482    show it to be incorrect.
4483
4484Version 1.6.1rc01 [March 21, 2013]
4485  No changes.
4486
4487Version 1.6.1 [March 28, 2013]
4488  No changes.
4489
4490Version 1.6.2beta01 [April 14, 2013]
4491  Updated documentation of 1.5.x to 1.6.x changes in iCCP chunk handling.
4492  Fixed incorrect warning of excess deflate data. End condition - the
4493    warning would be produced if the end of the deflate stream wasn't read
4494    in the last row.  The warning is harmless.
4495  Corrected the test on user transform changes on read. It was in the
4496    png_set of the transform function, but that doesn't matter unless the
4497    transform function changes the rowbuf size, and that is only valid if
4498    transform_info is called.
4499  Corrected a misplaced closing bracket in contrib/libtests/pngvalid.c
4500    (Flavio Medeiros).
4501  Corrected length written to uncompressed iTXt chunks (Samuli Suominen).
4502    Bug was introduced in libpng-1.6.0.
4503
4504Version 1.6.2rc01 [April 18, 2013]
4505  Added contrib/tools/fixitxt.c, to repair the erroneous iTXt chunk length
4506    written by libpng-1.6.0 and 1.6.1.
4507  Disallow storing sRGB information when the sRGB is not supported.
4508
4509Version 1.6.2rc02 [April 18, 2013]
4510  Merge pngtest.c with libpng-1.7.0
4511
4512Version 1.6.2rc03 [April 22, 2013]
4513  Trivial spelling cleanup.
4514
4515Version 1.6.2rc04 and 1.6.2rc05 [omitted]
4516
4517Version 1.6.2rc06 [April 24, 2013]
4518  Reverted to version 1.6.2rc03.  Recent changes to arm/neon support
4519    have been ported to libpng-1.7.0beta09 and will reappear in version
4520    1.6.3beta01.
4521
4522Version 1.6.2 [April 25, 2013]
4523  No changes.
4524
4525Version 1.6.3beta01 [April 25, 2013]
4526  Revised stack marking in arm/filter_neon.S and configure.ac.
4527  Ensure that NEON filter stuff is completely disabled when switched 'off'.
4528    Previously the ARM NEON specific files were still built if the option
4529    was switched 'off' as opposed to being explicitly disabled.
4530
4531Version 1.6.3beta02 [April 26, 2013]
4532  Test for 'arm*' not just 'arm' in the host_cpu configure variable.
4533  Rebuilt the configure scripts.
4534
4535Version 1.6.3beta03 [April 30, 2013]
4536  Expanded manual paragraph about writing private chunks, particularly
4537    the need to call png_set_keep_unknown_chunks() when writing them.
4538  Avoid dereferencing NULL pointer possibly returned from
4539    png_create_write_struct() (Andrew Church).
4540
4541Version 1.6.3beta05 [May 9, 2013]
4542  Calculate our own zlib windowBits when decoding rather than trusting the
4543    CMF bytes in the PNG datastream.
4544  Added an option to force maximum window size for inflating, which was
4545    the behavior of libpng15 and earlier, via a new PNG_MAXIMUM_INFLATE_WINDOW
4546    option for png_set_options().
4547  Added png-fix-itxt and png-fix-too-far-back to the built programs and
4548    removed warnings from the source code and timepng that are revealed as
4549    a result.
4550  Detect wrong libpng versions linked to png-fix-too-far-back, which currently
4551    only works with libpng versions that can be made to reliably fail when
4552    the deflate data contains an out-of-window reference.  This means only
4553    1.6 and later.
4554  Fixed gnu issues: g++ needs a static_cast, gcc 4.4.7 has a broken warning
4555    message which it is easier to work round than ignore.
4556  Updated contrib/pngminus/pnm2png.c (Paul Stewart):
4557    Check for EOF
4558    Ignore "#" delimited comments in input file to pnm2png.c.
4559    Fixed whitespace handling
4560    Added a call to png_set_packing()
4561    Initialize dimension values so if sscanf fails at least we have known
4562      invalid values.
4563  Attempt to detect configuration issues with png-fix-too-far-back, which
4564    requires both the correct libpng and the correct zlib to function
4565    correctly.
4566  Check ZLIB_VERNUM for mismatches, enclose #error in quotes
4567  Added information in the documentation about problems with and fixes for
4568    the bad CRC and bad iTXt chunk situations.
4569
4570Version 1.6.3beta06 [May 12, 2013]
4571  Allow contrib/pngminus/pnm2png.c to compile without WRITE_INVERT and
4572    WRITE_PACK supported (writes error message that it can't read P1 or
4573    P4 PBM files).
4574  Improved png-fix-too-far-back usage message, added --suffix option.
4575  Revised contrib/pngminim/*/makefile to generate pnglibconf.h with the
4576    right zlib header files.
4577  Separated CPPFLAGS and CFLAGS in contrib/pngminim/*/makefile
4578
4579Version 1.6.3beta07 [June 8, 2013]
4580  Removed a redundant test in png_set_IHDR().
4581  Added set(CMAKE_CONFIGURATION_TYPES ...) to CMakeLists.txt (Andrew Hundt)
4582  Deleted set(CMAKE_BUILD_TYPE) block from CMakeLists.txt
4583  Enclose the prototypes for the simplified write API in
4584    #ifdef PNG_STDIO_SUPPORTED/#endif
4585  Make ARM NEON support work at compile time (not just configure time).
4586    This moves the test on __ARM_NEON__ into pngconf.h to avoid issues when
4587    using a compiler that compiles for multiple architectures at one time.
4588  Removed PNG_FILTER_OPTIMIZATIONS and PNG_ARM_NEON_SUPPORTED from
4589    pnglibconf.h, allowing more of the decisions to be made internally
4590    (pngpriv.h) during the compile.  Without this, symbol prefixing is broken
4591    under certain circumstances on ARM platforms.  Now only the API parts of
4592    the optimizations ('check' vs 'api') are exposed in the public header files
4593    except that the new setting PNG_ARM_NEON_OPT documents how libpng makes the
4594    decision about whether or not to use the optimizations.
4595  Protect symbol prefixing against CC/CPPFLAGS/CFLAGS useage.
4596    Previous iOS/Xcode fixes for the ARM NEON optimizations moved the test
4597    on __ARM_NEON__ from configure time to compile time.  This breaks symbol
4598    prefixing because the definition of the special png_init_filter_functions
4599    call was hidden at configure time if the relevant compiler arguments are
4600    passed in CFLAGS as opposed to CC.  This change attempts to avoid all
4601    the confusion that would result by declaring the init function even when
4602    it is not used, so that it will always get prefixed.
4603
4604Version 1.6.3beta08 [June 18, 2013]
4605  Revised libpng.3 so that "doclifter" can process it.
4606
4607Version 1.6.3beta09 [June 27, 2013]
4608  Revised example.c to illustrate use of PNG_DEFAULT_sRGB and PNG_GAMMA_MAC_18
4609    as parameters for png_set_gamma().  These have been available since
4610    libpng-1.5.4.
4611  Renamed contrib/tools/png-fix-too-far-back.c to pngfix.c and revised it
4612    to check all compressed chunks known to libpng.
4613
4614Version 1.6.3beta10 [July 5, 2013]
4615  Updated documentation to show default behavior of benign errors correctly.
4616  Only compile ARM code when PNG_READ_SUPPORTED is defined.
4617  Fixed undefined behavior in contrib/tools/pngfix.c and added new strip
4618    option. pngfix relied on undefined behavior and even a simple change from
4619    gcc to g++ caused it to fail.  The new strip option 'unsafe' has been
4620    implemented and is the default if --max is given.  Option names have
4621    been clarified, with --strip=transform now stripping the bKGD chunk,
4622    which was stripped previously with --strip=unused.
4623  Added all documented chunk types to pngpriv.h
4624  Unified pngfix.c source with libpng17.
4625
4626Version 1.6.3rc01 [July 11, 2013]
4627  No changes.
4628
4629Version 1.6.3 [July 18, 2013]
4630  Revised manual about changes in iTXt chunk handling made in libpng-1.6.0.
4631  Added "/* SAFE */" comments in pngrutil.c and pngrtran.c where warnings
4632    may be erroneously issued by code-checking applications.
4633
4634Version 1.6.4beta01 [August 21, 2013]
4635  Added information about png_set_options() to the manual.
4636  Delay calling png_init_filter_functions() until a row with nonzero filter
4637    is found.
4638
4639Version 1.6.4beta02 [August 30, 2013]
4640  Fixed inconsistent conditional compilation of png_chunk_unknown_handling()
4641    prototype, definition, and usage.  Made it depend on
4642    PNG_HANDLE_AS_UNKNOWN_SUPPORTED everywhere.
4643
4644Version 1.6.4rc01 [September 5, 2013]
4645  No changes.
4646
4647Version 1.6.4 [September 12, 2013]
4648  No changes.
4649
4650Version 1.6.5 [September 14, 2013]
4651  Removed two stray lines of code from arm/arm_init.c.
4652
4653Version 1.6.6 [September 16, 2013]
4654  Removed two stray lines of code from arm/arm_init.c, again.
4655
4656Version 1.6.7beta01 [September 30, 2013]
4657  Revised unknown chunk code to correct several bugs in the NO_SAVE_/NO_WRITE
4658    combination
4659  Allow HANDLE_AS_UNKNOWN to work when other options are configured off. Also
4660    fixed the pngminim makefiles to work when $(MAKEFLAGS) contains stuff
4661    which terminates the make options (as by default in recent versions of
4662    Gentoo).
4663  Avoid up-cast warnings in pngvalid.c. On ARM the alignment requirements of
4664    png_modifier are greater than that of png_store and as a consequence
4665    compilation of pngvalid.c results in a warning about increased alignment
4666    requirements because of the bare cast to (png_modifier*). The code is safe,
4667    because the pointer is known to point to a stack allocated png_modifier,
4668    but this change avoids the warning.
4669  Fixed default behavior of ARM_NEON_API. If the ARM NEON API option was
4670    compiled without the CHECK option it defaulted to on, not off.
4671  Check user callback behavior in pngunknown.c. Previous versions compiled
4672    if SAVE_UNKNOWN was not available but did nothing since the callback
4673    was never implemented.
4674  Merged pngunknown.c with 1.7 version and back ported 1.7 improvements/fixes
4675
4676Version 1.6.7beta02 [October 12, 2013]
4677  Made changes for compatibility with automake 1.14:
4678    1) Added the 'compile' program to the list of programs that must be cleaned
4679       in autogen.sh
4680    2) Added 'subdir-objects' which causes .c files in sub-directories to be
4681       compiled such that the corresponding .o files are also in the
4682       sub-directory.  This is because automake 1.14 warns that the
4683       current behavior of compiling to the top level directory may be removed
4684       in the future.
4685    3) Updated dependencies on pnglibconf.h to match the new .o locations and
4686       added all the files in contrib/libtests and contrib/tools that depend
4687       on pnglibconf.h
4688    4) Added 'BUILD_SOURCES = pnglibconf.h'; this is the automake recommended
4689       way of handling the dependencies of sources that are machine generated;
4690       unfortunately it only works if the user does 'make all' or 'make check',
4691       so the dependencies (3) are still required.
4692  Cleaned up (char*) casts of zlib messages. The latest version of the Intel C
4693    compiler complains about casting a string literal as (char*), so copied the
4694    treatment of z_const from the library code into pngfix.c
4695  Simplified error message code in pngunknown. The simplification has the
4696    useful side effect of avoiding a bogus warning generated by the latest
4697    version of the Intel C compiler (it objects to
4698    condition ? string-literal : string-literal).
4699  Make autogen.sh work with automake 1.13 as well as 1.14. Do this by always
4700    removing the 1.14 'compile' script but never checking for it.
4701
4702Version 1.6.7beta03 [October 19, 2013]
4703  Added ARMv8 support (James Yu <james.yu at linaro.org>).  Added file
4704    arm/filter_neon_intrinsics.c; enable with -mfpu=neon.
4705  Revised pngvalid to generate size images with as many filters as it can
4706    manage, limited by the number of rows.
4707  Cleaned up ARM NEON compilation handling. The tests are now in pngpriv.h
4708    and detect the broken GCC compilers.
4709
4710Version 1.6.7beta04 [October 26, 2013]
4711  Allow clang derived from older GCC versions to use ARM intrinsics. This
4712    causes all clang builds that use -mfpu=neon to use the intrinsics code,
4713    not the assembler code.  This has only been tested on iOS 7. It may be
4714    necessary to exclude some earlier clang versions but this seems unlikely.
4715  Changed NEON implementation selection mechanism. This allows assembler
4716    or intrinsics to be turned on at compile time during the build by defining
4717    PNG_ARM_NEON_IMPLEMENTATION to the correct value (2 or 1).  This macro
4718    is undefined by default and the build type is selected in pngpriv.h.
4719
4720Version 1.6.7rc01 [November 2, 2013]
4721  No changes.
4722
4723Version 1.6.7rc02 [November 7, 2013]
4724  Fixed #include in filter_neon_intrinsics.c and ctype macros. The ctype char
4725    checking macros take an unsigned char argument, not a signed char.
4726
4727Version 1.6.7 [November 14, 2013]
4728  No changes.
4729
4730Version 1.6.8beta01 [November 24, 2013]
4731  Moved prototype for png_handle_unknown() in pngpriv.h outside of
4732    the #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED/#endif block.
4733  Added "-Wall" to CFLAGS in contrib/pngminim/*/makefile
4734  Conditionally compile some unused functions reported by -Wall in
4735    pngminim.
4736  Fixed 'minimal' builds. Various obviously useful minimal configurations
4737    don't build because of missing contrib/libtests test programs and
4738    overly complex dependencies in scripts/pnglibconf.dfa. This change
4739    adds contrib/conftest/*.dfa files that can be used in automatic build
4740    scripts to ensure that these configurations continue to build.
4741  Enabled WRITE_INVERT and WRITE_PACK in contrib/pngminim/encoder.
4742  Fixed pngvalid 'fail' function declaration on the Intel C Compiler.
4743    This reverts to the previous 'static' implementation and works round
4744    the 'unused static function' warning by using PNG_UNUSED().
4745
4746Version 1.6.8beta02 [November 30, 2013]
4747  Removed or marked PNG_UNUSED some harmless "dead assignments" reported
4748    by clang scan-build.
4749  Changed tabs to 3 spaces in png_debug macros and changed '"%s"m'
4750    to '"%s" m' to improve portability among compilers.
4751  Changed png_free_default() to free() in pngtest.c
4752
4753Version 1.6.8rc01 [December 12, 2013]
4754  Tidied up pngfix inits and fixed pngtest no-write builds.
4755
4756Version 1.6.8rc02 [December 14, 2013]
4757  Handle zero-length PLTE chunk or NULL palette with png_error()
4758    instead of png_chunk_report(), which by default issues a warning
4759    rather than an error, leading to later reading from a NULL pointer
4760    (png_ptr->palette) in png_do_expand_palette(). This is CVE-2013-6954
4761    and VU#650142.  Libpng-1.6.1 through 1.6.7 are vulnerable.
4762    Libpng-1.6.0 and earlier do not have this bug.
4763
4764Version 1.6.8 [December 19, 2013]
4765  No changes.
4766
4767Version 1.6.9beta01 [December 26, 2013]
4768  Bookkeeping: Moved functions around (no changes). Moved transform
4769    function definitions before the place where they are called so that
4770    they can be made static. Move the intrapixel functions and the
4771    grayscale palette builder out of the png?tran.c files. The latter
4772    isn't a transform function and is no longer used internally, and the
4773    former MNG specific functions are better placed in pngread/pngwrite.c
4774  Made transform implementation functions static. This makes the internal
4775    functions called by png_do_{read|write}_transformations static. On an
4776    x86-64 DLL build (Gentoo Linux) this reduces the size of the text
4777    segment of the DLL by 1208 bytes, about 0.6%. It also simplifies
4778    maintenance by removing the declarations from pngpriv.h and allowing
4779    easier changes to the internal interfaces.
4780  Rebuilt configure scripts with automake-1.14.1 and autoconf-2.69
4781    in the tar distributions.
4782
4783Version 1.6.9beta02 [January 1, 2014]
4784  Added checks for libpng 1.5 to pngvalid.c.  This supports the use of
4785    this version of pngvalid in libpng 1.5
4786  Merged with pngvalid.c from libpng-1.7 changes to create a single
4787    pngvalid.c
4788  Removed #error macro from contrib/tools/pngfix.c (Thomas Klausner).
4789  Merged pngrio.c, pngtrans.c, pngwio.c, and pngerror.c with libpng-1.7.0
4790  Merged libpng-1.7.0 changes to make no-interlace configurations work
4791    with test programs.
4792  Revised pngvalid.c to support libpng 1.5, which does not support the
4793    PNG_MAXIMUM_INFLATE_WINDOW option, so #define it out when appropriate in
4794    pngvalid.c
4795  Allow unversioned links created on install to be disabled in configure.
4796    In configure builds 'make install' changes/adds links like png.h
4797    and libpng.a to point to the newly installed, versioned, files (e.g.
4798    libpng17/png.h and libpng17.a). Three new configure options and some
4799    rearrangement of Makefile.am allow creation of these links to be disabled.
4800
4801Version 1.6.9beta03 [January 10, 2014]
4802  Removed potentially misleading warning from png_check_IHDR().
4803
4804Version 1.6.9beta04 [January 20, 2014]
4805  Updated scripts/makefile.* to use CPPFLAGS (Cosmin).
4806  Added clang attribute support (Cosmin).
4807
4808Version 1.6.9rc01 [January 28, 2014]
4809  No changes.
4810
4811Version 1.6.9rc02 [January 30, 2014]
4812  Quiet an uninitialized memory warning from VC2013 in png_get_png().
4813
4814Version 1.6.9 [February 6, 2014]
4815
4816Version 1.6.10beta01 [February 9, 2014]
4817  Backported changes from libpng-1.7.0beta30 and beta31:
4818  Fixed a large number of instances where PNGCBAPI was omitted from
4819    function definitions.
4820  Added pngimage test program for png_read_png() and png_write_png()
4821    with two new test scripts.
4822  Removed dependence on !PNG_READ_EXPAND_SUPPORTED for calling
4823    png_set_packing() in png_read_png().
4824  Fixed combination of ~alpha with shift. On read invert alpha, processing
4825    occurred after shift processing, which causes the final values to be
4826    outside the range that should be produced by the shift. Reversing the
4827    order on read makes the two transforms work together correctly and mirrors
4828    the order used on write.
4829  Do not read invalid sBIT chunks. Previously libpng only checked sBIT
4830    values on write, so a malicious PNG writer could therefore cause
4831    the read code to return an invalid sBIT chunk, which might lead to
4832    application errors or crashes.  Such chunks are now skipped (with
4833    chunk_benign_error).
4834  Make png_read_png() and png_write_png() prototypes in png.h depend
4835    upon PNG_READ_SUPPORTED and PNG_WRITE_SUPPORTED.
4836  Support builds with unsupported PNG_TRANSFORM_* values.  All of the
4837    PNG_TRANSFORM_* values are always defined in png.h and, because they
4838    are used for both read and write in some cases, it is not reliable
4839    to #if out ones that are totally unsupported. This change adds error
4840    detection in png_read_image() and png_write_image() to do a
4841    png_app_error() if the app requests something that cannot be done
4842    and it adds corresponding code to pngimage.c to handle such options
4843    by not attempting to test them.
4844
4845Version 1.6.10beta02 [February 23, 2014]
4846  Moved redefines of png_error(), png_warning(), png_chunk_error(),
4847    and png_chunk_warning() from pngpriv.h to png.h to make them visible
4848    to libpng-calling applications.
4849  Moved OS dependent code from arm/arm_init.c, to allow the included
4850    implementation of the ARM NEON discovery function to be set at
4851    build-time and provide sample implementations from the current code in the
4852    contrib/arm-neon subdirectory. The __linux__ code has also been changed to
4853    compile and link on Android by using /proc/cpuinfo, and the old linux code
4854    is in contrib/arm-neon/linux-auxv.c.  The new code avoids POSIX and Linux
4855    dependencies apart from opening /proc/cpuinfo and is C90 compliant.
4856  Check for info_ptr == NULL early in png_read_end() so we don't need to
4857    run all the png_handle_*() and depend on them to return if info_ptr == NULL.
4858    This improves the performance of png_read_end(png_ptr, NULL) and makes
4859    it more robust against future programming errors.
4860  Check for __has_extension before using it in pngconf.h, to
4861    support older Clang versions (Jeremy Sequoia).
4862  Treat CRC error handling with png_set_crc_action(), instead of with
4863    png_set_benign_errors(), which has been the case since libpng-1.6.0beta18.
4864  Use a user warning handler in contrib/gregbook/readpng2.c instead of default,
4865    so warnings will be put on stderr even if libpng has CONSOLE_IO disabled.
4866  Added png_ptr->process_mode = PNG_READ_IDAT_MODE in png_push_read_chunk
4867    after recognizing the IDAT chunk, which avoids an infinite loop while
4868    reading a datastream whose first IDAT chunk is of zero-length.
4869    This fixes CERT VU#684412 and CVE-2014-0333.
4870  Don't recognize known sRGB profiles as sRGB if they have been hacked,
4871    but don't reject them and don't issue a copyright violation warning.
4872
4873Version 1.6.10beta03 [February 25, 2014]
4874  Moved some documentation from png.h to libpng.3 and libpng-manual.txt
4875  Minor editing of contrib/arm-neon/README and contrib/examples/*.c
4876
4877Version 1.6.10rc01 [February 27, 2014]
4878  Fixed typos in the manual and in scripts/pnglibconf.dfa (CFLAGS -> CPPFLAGS
4879    and PNG_USR_CONFIG -> PNG_USER_CONFIG).
4880
4881Version 1.6.10rc02 [February 28, 2014]
4882  Removed unreachable return statement after png_chunk_error()
4883    in pngrutil.c
4884
4885Version 1.6.10rc03 [March 4, 2014]
4886  Un-deprecated png_data_freer().
4887
4888Version 1.6.10 [March 6, 2014]
4889  No changes.
4890
4891Version 1.6.11beta01 [March 17, 2014]
4892  Use "if (value != 0)" instead of "if (value)" consistently.
4893  Changed ZlibSrcDir from 1.2.5 to 1.2.8 in projects/vstudio.
4894  Moved configuration information from the manual to the INSTALL file.
4895
4896Version 1.6.11beta02 [April 6, 2014]
4897  Removed #if/#else/#endif from inside two pow() calls in pngvalid.c because
4898    they were handled improperly by Portland Group's PGI-14.1 - PGI-14.3
4899    when using its "__builtin_pow()" function.
4900  Silence 'unused parameter' build warnings (Cosmin Truta).
4901  $(CP) is now used alongside $(RM_F).  Also, use 'copy' instead of 'cp'
4902    where applicable, and applied other minor makefile changes (Cosmin).
4903  Don't warn about invalid dimensions exceeding user limits (Cosmin).
4904  Allow an easy replacement of the default pre-built configuration
4905    header with a custom header, via the make PNGLIBCONF_H_PREBUILT
4906    macro (Cosmin).
4907
4908Version 1.6.11beta03 [April 6, 2014]
4909  Fixed a typo in pngrutil.c, introduced in libpng-1.5.6, that interferes
4910    with "blocky" expansion of sub-8-bit interlaced PNG files (Eric Huss).
4911  Optionally use  __builtin_bswap16() in png_do_swap().
4912
4913Version 1.6.11beta04 [April 19, 2014]
4914  Made progressive reading of interlaced images consistent with the
4915    behavior of the sequential reader and consistent with the manual, by
4916    moving some code out of the PNG_READ_INTERLACING_SUPPORTED blocks. The
4917    row_callback now receives the proper pass number and unexpanded rows, when
4918    png_combine_row() isn't built or used, and png_set_interlace_handling()
4919    is not called.
4920  Allow PNG_sRGB_PROFILE_CHECKING = (-1) to mean no sRGB profile checking.
4921
4922Version 1.6.11beta05 [April 26, 2014]
4923  Do not reject ICC V2 profiles that lack padding (Kai-Uwe Behrmann).
4924  Relocated closing bracket of the sRGB profile test loop to avoid getting
4925    "Not recognizing known sRGB profile that has been edited" warning for
4926    ICC V2 profiles that lack the MD5 signature in the profile header.
4927
4928Version 1.6.11beta06 [May 19, 2014]
4929  Added PNG_SKIP_sRGB_CHECK_PROFILE choice for png_set_option().
4930
4931Version 1.6.11rc01 [May 27, 2014]
4932  No changes.
4933
4934Version 1.6.11rc02 [June 3, 2014]
4935  Test ZLIB_VERNUM instead of PNG_ZLIB_VERNUM in contrib/tools/pngfix.c
4936
4937Version 1.6.11 [June 5, 2014]
4938  No changes.
4939
4940Version 1.6.12rc01 [June 6, 2014]
4941  Relocated new code from 1.6.11beta06 in png.c to a point after the
4942    declarations (Max Stepin).
4943
4944Version 1.6.12rc02 [June 7, 2014]
4945  Changed file permissions of contrib/tools/intgamma.sh,
4946    test-driver, and compile from 0644 to 0755 (Cosmin).
4947
4948Version 1.6.12rc03 [June 8, 2014]
4949  Ensure "__has_attribute()" macro exists before trying to use it with
4950    old clang compilers (MacPorts Ticket #43939).
4951
4952Version 1.6.12 [June 12, 2014]
4953  No changes.
4954
4955Version 1.6.13beta01 [July 4, 2014]
4956  Quieted -Wsign-compare and -Wclobber compiler warnings in
4957    contrib/pngminus/*.c
4958  Added "(void) png_ptr;" where needed in contrib/gregbook to quiet
4959    compiler complaints about unused pointers.
4960  Split a long output string in contrib/gregbook/rpng2-x.c.
4961  Added "PNG_SET_OPTION" requirement for sRGB chunk support to pnglibconf.dfa,
4962    Needed for write-only support (John Bowler).
4963  Changed "if defined(__ARM_NEON__)" to
4964    "if (defined(__ARM_NEON__) || defined(__ARM_NEON))" (James Wu).
4965  Fixed clang no-warning builds: png_digit was defined but never used.
4966    
4967Version 1.6.13beta02 [July 21, 2014]
4968  Fixed an incorrect separator ("/" should be "\") in scripts/makefile.vcwin32
4969    (bug report from Wolfgang S. Kechel).  Bug was introduced in libpng-1.6.11.
4970    Also fixed makefile.bc32, makefile.bor, makefile.msc, makefile.intel, and
4971    makefile.tc3 similarly.
4972
4973Version 1.6.13beta03 [August 3, 2014]
4974  Removed scripts/makefile.elf. It has not worked since libpng-1.5.0beta14
4975    due to elimination of the PNG_FUNCTION_EXPORT and PNG_DATA_EXPORT
4976    definitions from pngconf.h.
4977  Ensure that CMakeLists.txt makes the target "lib" directory before making
4978    symbolic link into it (SourceForge bug report #226 by Rolf Timmermans).
4979
4980Version 1.6.13beta04 [August 8, 2014]
4981  Added opinion that the ECCN (Export Control Classification Number) for
4982    libpng is EAR99 to the README file.
4983  Eliminated use of "$<" in makefile explicit rules, when copying
4984    $PNGLIBCONF_H_PREBUILT.  This does not work on some versions of make;
4985    bug introduced in libpng version 1.6.11.
4986
4987Version 1.6.13rc01 [August 14, 2014]
4988  Made "ccopts" agree with "CFLAGS" in scripts/makefile.hp* and makefile.*sunu
4989
4990Version 1.6.13 [August 21, 2014]
4991  No changes.
4992
4993Version 1.6.14beta01 [September 14, 2014]
4994  Guard usage of png_ptr->options with #ifdef PNG_SET_OPTION_SUPPORTED.
4995  Do not build contrib/tools/pngfix.c when PNG_SETJMP_NOT_SUPPORTED,
4996    to allow "make" to complete without setjmp support (bug report by
4997    Claudio Fontana)
4998  Add "#include <setjmp.h>" to contrib/tools/pngfix.c (John Bowler)
4999
5000Version 1.6.14beta02 [September 18, 2014]
5001  Use nanosleep() instead of usleep() in contrib/gregbook/rpng2-x.c
5002    because usleep() is deprecated.
5003  Define usleep() in contrib/gregbook/rpng2-x.c if not already defined
5004    in unistd.h and nanosleep() is not available; fixes error introduced
5005    in libpng-1.6.13.
5006  Disable floating point exception handling in pngvalid.c when
5007    PNG_FLOATING_ARITHMETIC is not supported (bug report by "zootus
5008    at users.sourceforge.net").
5009
5010Version 1.6.14beta03 [September 19, 2014]
5011  Define FE_DIVBYZERO, FE_INVALID, and FE_OVERFLOW in pngvalid.c if not
5012    already defined.  Revert floating point exception handling in pngvalid.c
5013    to version 1.6.14beta01 behavior.
5014
5015Version 1.6.14beta04 [September 27, 2014]
5016  Fixed incorrect handling of the iTXt compression flag in pngrutil.c
5017    (bug report by Shunsaku Hirata).  Bug was introduced in libpng-1.6.0.
5018
5019Version 1.6.14beta05 [October 1, 2014]
5020  Added "option READ_iCCP enables READ_COMPRESSED_TEXT" to pnglibconf.dfa
5021
5022Version 1.6.14beta06 [October 5, 2014]
5023  Removed unused "text_len" parameter from private function png_write_zTXt().
5024  Conditionally compile some code in png_deflate_claim(), when
5025    PNG_WARNINGS_SUPPORTED and PNG_ERROR_TEXT_SUPPORTED are disabled.
5026  Replaced repeated code in pngpread.c with PNG_PUSH_SAVE_BUFFER_IF_FULL.
5027  Added "chunk iTXt enables TEXT" and "chunk zTXt enables TEXT"
5028    to pnglibconf.dfa.
5029  Removed "option READ_COMPRESSED_TEXT enables READ_TEXT" from pnglibconf.dfa,
5030    to make it possible to configure a libpng that supports iCCP but not TEXT.
5031
5032Version 1.6.14beta07 [October 7, 2014]
5033  Removed "option WRITE_COMPRESSED_TEXT enables WRITE_TEXT" from pnglibconf.dfa
5034  Only mark text chunks as written after successfully writing them.
5035
5036Version 1.6.14rc01 [October 15, 2014]
5037  Fixed some typos in comments.
5038
5039Version 1.6.14rc02 [October 17, 2014]
5040  Changed png_convert_to_rfc_1123() to png_convert_to_rfc_1123_buffer()
5041    in the manual, to reflect the change made in libpng-1.6.0.
5042  Updated README file to explain that direct access to the png_struct
5043    and info_struct members has not been permitted since libpng-1.5.0.
5044
5045Version 1.6.14 [October 23, 2014]
5046  No changes.
5047
5048Version 1.6.15beta01 [October 29, 2014]
5049  Changed "if (!x)" to "if (x == 0)" and "if (x)" to "if (x != 0)"
5050  Simplified png_free_data().
5051  Added missing "ptr = NULL" after some instances of png_free().
5052
5053Version 1.6.15beta02 [November 1, 2014]
5054  Changed remaining "if (!x)" to "if (x == 0)" and "if (x)" to "if (x != 0)"
5055
5056Version 1.6.15beta03 [November 3, 2014]
5057  Added PNG_USE_ARM_NEON configuration flag (Marcin Juszkiewicz).
5058
5059Version 1.6.15beta04 [November 4, 2014]
5060  Removed new PNG_USE_ARM_NEON configuration flag and made a one-line
5061    revision to configure.ac to support ARM on aarch64 instead (John Bowler).
5062
5063Version 1.6.15beta05 [November 5, 2014]
5064  Use png_get_libpng_ver(NULL) instead of PNG_LIBPNG_VER_STRING in
5065    example.c, pngtest.c, and applications in the contrib directory.
5066  Fixed an out-of-range read in png_user_version_check() (Bug report from
5067    Qixue Xiao, CVE-2015-8540).
5068  Simplified and future-proofed png_user_version_check().
5069  Fixed GCC unsigned int->float warnings. Various versions of GCC
5070    seem to generate warnings when an unsigned value is implicitly
5071    converted to double. This is probably a GCC bug but this change
5072    avoids the issue by explicitly converting to (int) where safe.
5073  Free all allocated memory in pngimage. The file buffer cache was left
5074    allocated at the end of the program, harmless but it causes memory
5075    leak reports from clang.
5076  Fixed array size calculations to avoid warnings. At various points
5077    in the code the number of elements in an array is calculated using
5078    sizeof.  This generates a compile time constant of type (size_t) which
5079    is then typically assigned to an (unsigned int) or (int). Some versions
5080    of GCC on 64-bit systems warn about the apparent narrowing, even though
5081    the same compiler does apparently generate the correct, in-range,
5082    numeric constant.  This adds appropriate, safe, casts to make the
5083    warnings go away.
5084
5085Version 1.6.15beta06 [November 6, 2014]
5086  Reverted use png_get_libpng_ver(NULL) instead of PNG_LIBPNG_VER_STRING
5087    in the manual, example.c, pngtest.c, and applications in the contrib
5088    directory.  It was incorrect advice.
5089
5090Version 1.6.15beta07 [November 7, 2014]
5091  Removed #ifdef PNG_16BIT_SUPPORTED/#endif around png_product2(); it is
5092    needed by png_reciprocal2().
5093  Added #ifdef PNG_16BIT_SUPPORTED/#endif around png_log16bit() and
5094    png_do_swap().
5095  Changed all "#endif /* PNG_FEATURE_SUPPORTED */" to "#endif /* FEATURE */"
5096
5097Version 1.6.15beta08 [November 8, 2014]
5098  More housecleaning in *.h
5099
5100Version 1.6.15rc01 [November 13, 2014]
5101
5102Version 1.6.15rc02 [November 14, 2014]
5103  The macros passed in the command line to Borland make were ignored if
5104    similarly-named macros were already defined in makefiles. This behavior
5105    is different from POSIX make and other make programs.  Surround the
5106    macro definitions with ifndef guards (Cosmin).
5107
5108Version 1.6.15rc03 [November 16, 2014]
5109  Added "-D_CRT_SECURE_NO_WARNINGS" to CFLAGS in scripts/makefile.vcwin32.
5110  Removed the obsolete $ARCH variable from scripts/makefile.darwin.
5111
5112Version 1.6.15 [November 20, 2014]
5113  No changes.
5114
5115Version 1.6.16beta01 [December 14, 2014]
5116  Added ".align 2" to arm/filter_neon.S to support old GAS assemblers that
5117    don't do alignment correctly.
5118  Revised Makefile.am and scripts/symbols.dfn to work with MinGW/MSYS
5119    (Bob Friesenhahn).
5120
5121Version 1.6.16beta02 [December 15, 2014]
5122  Revised Makefile.am and scripts/*.dfn again to work with MinGW/MSYS;
5123    renamed scripts/*.dfn to scripts/*.c (John Bowler).
5124
5125Version 1.6.16beta03 [December 21, 2014]
5126  Quiet a "comparison always true" warning in pngstest.c (John Bowler).
5127
5128Version 1.6.16rc01 [December 21, 2014]
5129  Restored a test on width that was removed from png.c at libpng-1.6.9
5130    (Bug report by Alex Eubanks, CVE-2015-0973).
5131
5132Version 1.6.16rc02 [December 21, 2014]
5133  Undid the update to pngrutil.c in 1.6.16rc01.
5134
5135Version 1.6.16rc03 [December 21, 2014]
5136  Fixed an overflow in png_combine_row() with very wide interlaced images
5137    (Bug report and fix by John Bowler, CVE-2014-9495).
5138
5139Version 1.6.16 [December 22, 2014]
5140  No changes.
5141
5142Version 1.6.17beta01 [January 29, 2015]
5143  Removed duplicate PNG_SAFE_LIMITS_SUPPORTED handling from pngconf.h
5144  Corrected the width limit calculation in png_check_IHDR().
5145  Removed user limits from pngfix. Also pass NULL pointers to
5146    png_read_row to skip the unnecessary row de-interlace stuff.
5147  Added testing of png_set_packing() to pngvalid.c
5148  Regenerated configure scripts in the *.tar distributions with libtool-2.4.4
5149  Implement previously untested cases of libpng transforms in pngvalid.c
5150  Fixed byte order in png_do_read_filler() with 16-bit input. Previously
5151    the high and low bytes of the filler, from png_set_filler() or from
5152    png_set_add_alpha(), were read in the wrong order.
5153  Made the check for out-of-range values in png_set_tRNS() detect
5154    values that are exactly 2^bit_depth, and work on 16-bit platforms.
5155  Merged some parts of libpng-1.6.17beta01 and libpng-1.7.0beta47.
5156  Added #ifndef __COVERITY__ where needed in png.c, pngrutil.c and
5157    pngset.c to avoid warnings about dead code.
5158  Added "& 0xff" to many instances of expressions that are typecast
5159    to (png_byte), to avoid Coverity warnings.
5160
5161Version 1.6.17beta02 [February 7, 2015]
5162  Work around one more Coverity-scan dead-code warning.
5163  Do not build png_product2() when it is unused.
5164
5165Version 1.6.17beta03 [February 17, 2015]
5166  Display user limits in the output from pngtest.
5167  Eliminated the PNG_SAFE_LIMITS macro and restored the 1-million-column
5168    and 1-million-row default limits in pnglibconf.dfa, that can be reset
5169    by the user at build time or run time.  This provides a more robust
5170    defense against DOS and as-yet undiscovered overflows.
5171
5172Version 1.6.17beta04 [February 21, 2015]
5173  Added PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED macro, on by default.
5174  Allow user to call png_get_IHDR() with NULL arguments (Reuben Hawkins).
5175  Rebuilt configure scripts with automake-1.15 and libtool-2.4.6
5176
5177Version 1.6.17beta05 [February 25, 2015]
5178  Restored compiling of png_reciprocal2 with PNG_NO_16BIT.
5179
5180Version 1.6.17beta06 [February 27, 2015]
5181  Moved png_set_filter() prototype into a PNG_WRITE_SUPPORTED block
5182    of png.h.
5183  Avoid runtime checks when converting integer to png_byte with
5184    Visual Studio (Sergey Kosarevsky)
5185
5186Version 1.6.17rc01 [March 4, 2015]
5187  No changes.
5188
5189Version 1.6.17rc02 [March 9, 2015]
5190  Removed some comments that the configure script did not handle
5191    properly from scripts/pnglibconf.dfa and pnglibconf.h.prebuilt.
5192  Free the unknown_chunks structure even when it contains no data.
5193
5194Version 1.6.17rc03 [March 12, 2015]
5195  Updated CMakeLists.txt to add OSX framework, change YES/NO to ON/OFF
5196    for consistency, and remove some useless tests (Alexey Petruchik).
5197
5198Version 1.6.17rc04 [March 16, 2015]
5199  Remove pnglibconf.h, pnglibconf.c, and pnglibconf.out instead of
5200    pnglibconf.* in "make clean" (Cosmin).
5201  Fix bug in calculation of maxbits, in png_write_sBIT, introduced
5202    in libpng-1.6.17beta01 (John Bowler).
5203
5204Version 1.6.17rc05 [March 21, 2015]
5205  Define PNG_FILTER_* and PNG_FILTER_VALUE_* in png.h even when WRITE
5206    is not supported (John Bowler).  This fixes an error introduced in
5207    libpng-1.6.17beta06.
5208  Reverted "& 0xff" additions of version 1.6.17beta01. Libpng passes
5209    the Coverity scan without them.
5210
5211Version 1.6.17rc06 [March 23, 2015]
5212  Remove pnglibconf.dfn and pnglibconf.pre with "make clean".
5213  Reformatted some "&0xff" instances to "& 0xff".
5214  Fixed simplified 8-bit-linear to sRGB alpha. The calculated alpha
5215    value was wrong.  It's not clear if this affected the final stored
5216    value; in the obvious code path the upper and lower 8-bits of the
5217    alpha value were identical and the alpha was truncated to 8-bits
5218    rather than dividing by 257 (John Bowler).
5219
5220Version 1.6.17 [March 26, 2015]
5221  No changes.
5222
5223Version 1.6.18beta01 [April 1, 2015]
5224  Removed PNG_SET_CHUNK_[CACHE|MALLOC]_LIMIT_SUPPORTED macros.  They
5225    have been combined with PNG_SET_USER_LIMITS_SUPPORTED (resolves
5226    bug report by Andrew Church).
5227  Fixed rgb_to_gray checks and added tRNS checks to pngvalid.c.  This
5228    fixes some arithmetic errors that caused some tests to fail on
5229    some 32-bit platforms (Bug reports by Peter Breitenlohner [i686]
5230    and Petr Gajdos [i586]).
5231
5232Version 1.6.18beta02 [April 26, 2015]
5233  Suppressed some warnings from the Borland C++ 5.5.1/5.82 compiler
5234    (Bug report by Viktor Szakats).
5235
5236Version 1.6.18beta03 [May 6, 2015]
5237  Replaced "unexpected" with an integer (0xabadca11) in pngset.c
5238    where a long was expected, to avoid a compiler warning when PNG_DEBUG > 1.
5239  Added contrib/examples/simpleover.c, to demonstrate how to handle
5240    alpha compositing of multiple images, using the "simplified API"
5241    and an example PNG generation tool, contrib/examples/genpng.c
5242    (John Bowler).
5243
5244Version 1.6.18beta04 [May 20, 2015]
5245  PNG_RELEASE_BUILD replaces tests where the code depended on the build base
5246    type and can be defined on the command line, allowing testing in beta
5247    builds (John Bowler).
5248  Avoid Coverity issue 80858 (REVERSE NULL) in pngtest.c PNG_DEBUG builds.
5249  Avoid a harmless potential integer overflow in png_XYZ_from_xy() (Bug
5250    report from Christopher Ferris).
5251
5252Version 1.6.18beta05 [May 31, 2015]
5253  Backport filter selection code from libpng-1.7.0beta51, to combine
5254    sub_row, up_row, avg_row, and paeth_row into try_row and tst_row.
5255  Changed png_voidcast(), etc., to voidcast(), etc., in contrib/tools/pngfix.c
5256    to avoid confusion with the libpng private macros.
5257  Fixed old cut&paste bug in the weighted filter selection code in
5258    pngwutil.c, introduced in libpng-0.95, March 1997.
5259
5260Version 1.6.18beta06 [June 1, 2015]
5261  Removed WRITE_WEIGHTED_FILTERED code, to save a few kbytes of the
5262    compiled library size. It never worked properly and as far as we can
5263    tell, no one uses it. The png_set_filter_heuristics() and
5264    png_set_filter_heuristics_fixed() APIs are retained but deprecated
5265    and do nothing.
5266
5267Version 1.6.18beta07 [June 6, 2015]
5268  Removed non-working progressive reader 'skip' function. This
5269    function has apparently never been used. It was implemented
5270    to support back-door modification of png_struct in libpng-1.4.x
5271    but (because it does nothing and cannot do anything) was apparently
5272    never tested (John Bowler).
5273  Fixed cexcept.h in which GCC 5 now reports that one of the auto
5274    variables in the Try macro needs to be volatile to prevent value
5275    being lost over the setjmp (John Bowler).
5276  Fixed NO_WRITE_FILTER and -Wconversion build breaks (John Bowler).
5277  Fix g++ build breaks (John Bowler).
5278  Quieted some Coverity issues in pngfix.c, png-fix-itxt.c, pngvalid.c,
5279    pngstest.c, and pngimage.c. Most seem harmless, but png-fix-itxt
5280    would only work with iTXt chunks with length 255 or less.
5281  Added #ifdef's to contrib/examples programs so people don't try
5282    to compile them without the minimum required support enabled
5283    (suggested by Flavio Medeiros).
5284
5285Version 1.6.18beta08 [June 30, 2015]
5286  Eliminated the final two Coverity defects (insecure temporary file
5287    handling in contrib/libtests/pngstest.c; possible overflow of
5288    unsigned char in contrib/tools/png-fix-itxt.c). To use the "secure"
5289    file handling, define PNG_USE_MKSTEMP, otherwise "tmpfile()" will
5290    be used.
5291  Removed some unused WEIGHTED_FILTER macros from png.h and pngstruct.h
5292
5293Version 1.6.18beta09 [July 5, 2015]
5294  Removed some useless typecasts from contrib/tools/png-fix-itxt.c
5295  Fixed a new signed-unsigned comparison in pngrtran.c (Max Stepin).
5296  Replaced arbitrary use of 'extern' with #define PNG_LINKAGE_*.  To
5297    preserve API compatibility, the new defines all default to "extern"
5298    (requested by Jan Nijtmans).
5299
5300Version 1.6.18rc01 [July 9, 2015]
5301  Belatedly added Mans Rullgard and James Yu to the list of Contributing
5302    Authors.
5303
5304Version 1.6.18rc02 [July 12, 2015]
5305  Restored unused FILTER_HEURISTIC macros removed at libpng-1.6.18beta08
5306    to png.h to avoid compatibility warnings.
5307
5308Version 1.6.18rc03 [July 15, 2015]
5309  Minor changes to the man page
5310
5311Version 1.6.18 [July 23, 2015]
5312  No changes.
5313
5314Version 1.6.19beta01 [July 30, 2015]
5315  Updated obsolete information about the simplified API macros in the
5316    manual pages (Bug report by Arc Riley).
5317  Avoid potentially dereferencing NULL info_ptr in png_info_init_3().
5318  Rearranged png.h to put the major sections in the same order as
5319    in libpng17.
5320  Eliminated unused PNG_COST_SHIFT, PNG_WEIGHT_SHIFT, PNG_COST_FACTOR, and
5321    PNG_WEIGHT_FACTOR macros.
5322  Suppressed some warnings from the Borland C++ 5.5.1/5.82 compiler
5323    (Bug report by Viktor Szakats).  Several warnings remain and are
5324    unavoidable, where we test for overflow.
5325  Fixed potential leak of png_pixels in contrib/pngminus/pnm2png.c
5326  Fixed uninitialized variable in contrib/gregbook/rpng2-x.c
5327
5328Version 1.6.19beta02 [August 19, 2015]
5329  Moved config.h.in~ from the "libpng_autotools_files" list to the
5330    "libpng_autotools_extra" list in autogen.sh because it was causing a
5331    false positive for missing files (bug report by Robert C. Seacord).
5332  Removed unreachable "break" statements in png.c, pngread.c, and pngrtran.c
5333    to suppress clang warnings (Bug report by Viktor Szakats).
5334  Fixed some bad links in the man page.
5335  Changed "n bit" to "n-bit" in comments.
5336  Added signed/unsigned 16-bit safety net. This removes the dubious
5337    0x8000 flag definitions on 16-bit systems. They aren't supported
5338    yet the defs *probably* work, however it seems much safer to do this
5339    and be advised if anyone, contrary to advice, is building libpng 1.6
5340    on a 16-bit system. It also adds back various switch default clauses
5341    for GCC; GCC errors out if they are not present (with an appropriately
5342    high level of warnings).
5343  Safely convert num_bytes to a png_byte in png_set_sig_bytes() (Robert
5344    Seacord).
5345  Fixed the recently reported 1's complement security issue by replacing
5346    the value that is illegal in the PNG spec, in both signed and unsigned
5347    values, with 0. Illegal unsigned values (anything greater than or equal
5348    to  0x80000000) can still pass through, but since these are not illegal
5349    in ANSI-C (unlike 0x80000000 in the signed case) the checking that
5350    occurs later can catch them (John Bowler).
5351
5352Version 1.6.19beta03 [September 26, 2015]
5353  Fixed png_save_int_32 when int is not 2's complement (John Bowler).
5354  Updated libpng16 with all the recent test changes from libpng17,
5355    including changes to pngvalid.c to ensure that the original,
5356    distributed, version of contrib/visupng/cexcept.h can be used
5357    (John Bowler).
5358  pngvalid contains the correction to the use of SAVE/STORE_
5359    UNKNOWN_CHUNKS; a bug revealed by changes in libpng 1.7. More
5360    tests contain the --strict option to detect warnings and the
5361    pngvalid-standard test has been corrected so that it does not
5362    turn on progressive-read. There is a separate test which does
5363    that. (John Bowler)
5364  Also made some signed/unsigned fixes.
5365  Make pngstest error limits version specific. Splitting the machine
5366    generated error structs out to a file allows the values to be updated
5367    without changing pngstest.c itself. Since libpng 1.6 and 1.7 have
5368    slightly different error limits this simplifies maintenance. The
5369    makepngs.sh script has also been updated to more accurately reflect
5370    current problems in libpng 1.7 (John Bowler).
5371  Incorporated new test PNG files into make check.  tests/pngstest-*
5372    are changed so that the new test files are divided into 8 groups by
5373    gamma and alpha channel.  These tests have considerably better code
5374    and pixel-value coverage than contrib/pngsuite; however,coverage is
5375    still incomplete (John Bowler).
5376  Removed the '--strict' in 1.6 because of the double-gamma-correction
5377    warning, updated pngstest-errors.h for the errors detected with the
5378    new contrib/testspngs PNG test files (John Bowler).
5379
5380Version 1.6.19beta04 [October 15, 2015]
5381  Worked around rgb-to-gray issues in libpng 1.6.  The previous
5382    attempts to ignore the errors in the code aren't quite enough to
5383    deal with the 'channel selection' encoding added to libpng 1.7; abort.
5384    pngvalid.c is changed to drop this encoding in prior versions.
5385  Fixed 'pow' macros in pngvalid.c. It is legal for 'pow' to be a
5386    macro, therefore the argument list cannot contain preprocessing
5387    directives.  Make sure pow is a function where this happens. This is
5388    a minimal safe fix, the issue only arises in non-performance-critical
5389    code (bug report by Curtis Leach, fix by John Bowler).
5390  Added sPLT support to pngtest.c
5391
5392Version 1.6.19rc01 [October 23, 2015]
5393  No changes.
5394
5395Version 1.6.19rc02 [October 31, 2015]
5396  Prevent setting or writing over-length PLTE chunk (Cosmin Truta).
5397  Silently truncate over-length PLTE chunk while reading.
5398  Libpng incorrectly calculated the output rowbytes when the application
5399    decreased either the number of channels or the bit depth (or both) in
5400    a user transform.  This was safe; libpng overallocated buffer space
5401   (potentially by quite a lot; up to 4 times the amount required) but,
5402   from 1.5.4 on, resulted in a png_error (John Bowler).
5403
5404Version 1.6.19rc03 [November 3, 2015]
5405  Fixed some inconsequential cut-and-paste typos in png_set_cHRM_XYZ_fixed().
5406  Clarified COPYRIGHT information to state explicitly that versions
5407    are derived from previous versions.
5408  Removed much of the long list of previous versions from png.h and
5409    libpng.3.
5410
5411Version 1.6.19rc04 [November 5, 2015]
5412  Fixed new bug with CRC error after reading an over-length palette
5413    (bug report by Cosmin Truta) (CVE-2015-8126).
5414
5415Version 1.6.19 [November 12, 2015]
5416  Cleaned up coding style in png_handle_PLTE().
5417
5418Version 1.6.20beta01 [November 20, 2015]
5419  Avoid potential pointer overflow/underflow in png_handle_sPLT() and
5420    png_handle_pCAL() (Bug report by John Regehr).
5421
5422Version 1.6.20beta02 [November 23, 2015]
5423  Fixed incorrect implementation of png_set_PLTE() that uses png_ptr
5424    not info_ptr, that left png_set_PLTE() open to the CVE-2015-8126
5425    vulnerability.  Fixes CVE-2015-8472.
5426
5427Version 1.6.20beta03 [November 24, 2015]
5428  Backported tests from libpng-1.7.0beta69.
5429
5430Version 1.6.20rc01 [November 26, 2015]
5431  Fixed an error in handling of bad zlib CMINFO field in pngfix, found by
5432    American Fuzzy Lop, reported by Brian Carpenter.  inflate() doesn't
5433    immediately fault a bad CMINFO field; instead a 'too far back' error
5434    happens later (at least some times).  pngfix failed to limit CMINFO to
5435    the allowed values but then assumed that window_bits was in range,
5436    triggering an assert. The bug is mostly harmless; the PNG file cannot
5437    be fixed.
5438
5439Version 1.6.20rc02 [November 29, 2015]
5440  In libpng 1.6 zlib initialization was changed to use the window size
5441    in the zlib stream, not a fixed value. This causes some invalid images,
5442    where CINFO is too large, to display 'correctly' if the rest of the
5443    data is valid.  This provides a workaround for zlib versions where the
5444    error arises (ones that support the API change to use the window size
5445    in the stream).
5446
5447Version 1.6.20 [December 3, 2015]
5448  No changes.
5449
5450Version 1.6.21beta01 [December 11, 2015]
5451  Fixed syntax "$(command)" in tests/pngstest that some shells other than
5452    bash could not parse (Bug report by Nelson Beebe). Use `command` instead.
5453
5454Version 1.6.21beta02 [December 14, 2015]
5455  Moved png_check_keyword() from pngwutil.c to pngset.c
5456  Removed LE/BE dependencies in pngvalid, to 'fix' the current problem
5457    in the BigEndian tests by not testing it, making the BE code the same 
5458    as the LE version.
5459  Fixes to pngvalid for various reduced build configurations (eliminate unused
5460    statics) and a fix for the case in rgb_to_gray when the digitize option
5461    reduces graylo to 0, producing a large error.
5462
5463Version 1.6.21beta03 [December 18, 2015]
5464  Widened the 'limit' check on the internally calculated error limits in
5465    the 'DIGITIZE' case (the code used prior to 1.7 for rgb_to_gray error
5466    checks) and changed the check to only operate in non-release builds
5467    (base build type not RC or RELEASE.)
5468  Fixed undefined behavior in pngvalid.c, undefined because
5469    (png_byte) << shift is undefined if it changes the signed bit
5470    (because png_byte is promoted to int). The libpng exported functions
5471    png_get_uint_32 and png_get_uint_16 handle this. (Bug reported by
5472    David Drysdale as a result of reports from UBSAN in clang 3.8).
5473  This changes pngvalid to use BE random numbers; this used to produce
5474    errors but these should not be fixed as a result of the previous changes.
5475
5476Version 1.6.21rc01 [January 4, 2016]
5477  In projects/vstudio, combined readme.txt and WARNING into README.txt
5478
5479Version 1.6.21rc02 [January 7, 2016]
5480  Relocated assert() in contrib/tools/pngfix.c, bug found by American
5481    Fuzzy Lop, reported by Brian Carpenter.
5482  Marked 'limit' UNUSED in transform_range_check().  This only affects
5483    release builds.
5484
5485Version 1.6.21 [January 15, 2016]
5486  Worked around a false-positive Coverity issue in pngvalid.c.
5487
5488Version 1.6.22beta01 [January 23, 2016]
5489  Changed PNG_USE_MKSTEMP to __COVERITY__ to select alternate
5490    "tmpfile()" implementation in contrib/libtests/pngstest.c
5491  Fixed NO_STDIO build of pngunknown.c to skip calling png_init_io()
5492    if there is no stdio.h support.
5493  Added a png_image_write_to_memory() API and a number of assist macros
5494    to allow an application that uses the simplified API write to bypass
5495    stdio and write directly to memory.
5496  Added some warnings (png.h) and some check code to detect *possible*
5497    overflow in the ROW_STRIDE and simplified image SIZE macros.  This
5498    disallows image width/height/format that *might* overflow.  This is
5499    a quiet API change that limits in-memory image size (uncompressed) to
5500    less than 4GByte and image row size (stride) to less than 2GByte.
5501  Revised workaround for false-positive Coverity issue in pngvalid.c.
5502
5503Version 1.6.22beta02 [February 8, 2016]
5504  Only use exit(77) in configure builds.
5505  Corrected error in PNG_IMAGE_PNG_SIZE_MAX. This new macro underreported
5506    the palette size because it failed to take into account that the memory
5507    palette has to be expanded to full RGB when it is written to PNG.
5508  Updated CMakeLists.txt, added supporting scripts/gen*.cmake.in
5509    and test.cmake.in (Roger Leigh).
5510  Relaxed limit checks on gamma values in pngrtran.c. As suggested in
5511    the comments gamma values outside the range currently permitted
5512    by png_set_alpha_mode are useful for HDR data encoding.  These values
5513    are already permitted by png_set_gamma so it is reasonable caution to
5514    extend the png_set_alpha_mode range as HDR imaging systems are starting
5515    to emerge.
5516
5517Version 1.6.22beta03 [March 9, 2016]
5518  Added a common-law trademark notice and export control information
5519    to the LICENSE file, png.h, and the man page.
5520  Restored "& 0xff" in png_save_uint_16() and png_save_uint_32() that
5521    were accidentally removed from libpng-1.6.17. 
5522  Changed PNG_INFO_cHNK and PNG_FREE_cHNK from 0xnnnn to 0xnnnnU in png.h
5523    (Robert C. Seacord).
5524  Removed dubious "#if INT_MAX" test from png.h that was added to
5525    libpng-1.6.19beta02 (John Bowler).
5526  Add ${INCLUDES} in scripts/genout.cmake.in (Bug report by Nixon Kwok).
5527  Updated LICENSE to say files in the contrib directory are not
5528    necessarily under the libpng license, and that some makefiles have
5529    other copyright owners.
5530  Added INTEL-SSE2 support (Mike Klein and Matt Sarett, Google, Inc.).
5531  Made contrib/libtests/timepng more robust.  The code no longer gives
5532    up/fails on invalid PNG data, it just skips it (with error messages).
5533    The code no longer fails on PNG files with data beyond IEND.  Options
5534    exist to use png_read_png (reading the whole image, not by row) and, in
5535    that case, to apply any of the supported transforms.  This makes for
5536    more realistic testing; the decoded data actually gets used in a
5537    meaningful fashion (John Bowler).
5538  Fixed some misleading indentation (Krishnaraj Bhat).
5539
5540Version 1.6.22beta04 [April 5, 2016]
5541  Force GCC compilation to C89 if needed (Dagobert Michelsen).
5542  SSE filter speed improvements for bpp=3:
5543    memcpy-free implementations of load3() / store3().
5544    call load3() only when needed at the end of a scanline.
5545
5546Version 1.6.22beta05 [April 27, 2016]
5547  Added PNG_FAST_FILTERS macro (defined as
5548    PNG_FILTER_NONE|PNG_FILTER_SUB|PNG_FILTER_UP).
5549  Various fixes for contrib/libtests/timepng.c
5550  Moved INTEL-SSE code from pngpriv.h into contrib/intel/intel_sse.patch.
5551  Fixed typo (missing underscore) in #define PNG_READ_16_TO_8_SUPPORTED
5552    (Bug report by Y.Ohashik).
5553
5554Version 1.6.22beta06 [May 5, 2016]
5555  Rebased contrib/intel_sse.patch.
5556  Quieted two Coverity issues in contrib/libtests/timepng.c.
5557  Fixed issues with scripts/genout.cmake.in (David Capello, Nixon Kwok):
5558    Added support to use multiple directories in ZLIBINCDIR variable,
5559    Fixed CMAKE_C_FLAGS with multiple values when genout is compiled on MSVC,
5560    Fixed pnglibconf.c compilation on OS X including the sysroot path.
5561
5562Version 1.6.22rc01 [May 14, 2016]
5563  No changes.
5564
5565Version 1.6.22rc02 [May 16, 2016]
5566  Removed contrib/timepng from default build; it does not build on platforms
5567    that don't supply clock_gettime().
5568
5569Version 1.6.22rc03 [May 17, 2016]
5570  Restored contrib/timepng to default build but check for the presence
5571    of clock_gettime() in configure.ac and Makefile.am.
5572
5573Version 1.6.22 [May 26, 2016]
5574  No changes.
5575
5576Version 1.6.23beta01 [May 29, 2016]
5577  Stop a potential memory leak in png_set_tRNS() (Bug report by Ted Ying).
5578  Fixed the progressive reader to handle empty first IDAT chunk properly
5579    (patch by Timothy Nikkel).  This bug was introduced in libpng-1.6.0 and
5580    only affected the libpng16 branch.
5581  Added tests in pngvalid.c to check zero-length IDAT chunks in various
5582    positions.  Fixed the sequential reader to handle these more robustly
5583    (John Bowler).
5584
5585Version 1.6.23rc01 [June 2, 2016]
5586  Corrected progressive read input buffer in pngvalid.c. The previous version
5587    the code invariably passed just one byte at a time to libpng.  The intent
5588    was to pass a random number of bytes in the range 0..511.
5589  Moved sse2 prototype from pngpriv.h to contrib/intel/intel_sse.patch.
5590  Added missing ")" in pngerror.c (Matt Sarrett).
5591
5592Version 1.6.23rc02 [June 4, 2016]
5593  Fixed undefined behavior in png_push_save_buffer(). Do not call
5594    memcpy() with a null source, even if count is zero (Leon Scroggins III).
5595
5596Version 1.6.23 [June 9, 2016]
5597  Fixed bad link to RFC2083 in png.5 (Nikola Forro).
5598
5599Version 1.6.24beta01 [June 11, 2016]
5600  Avoid potential overflow of the PNG_IMAGE_SIZE macro.  This macro
5601    is not used within libpng, but is used in some of the examples.
5602
5603Version 1.6.24beta02 [June 23, 2016]
5604  Correct filter heuristic overflow handling. This was broken when the
5605    write filter code was moved out-of-line; if there is a single filter and
5606    the heuristic sum overflows the calculation of the filtered line is not
5607    completed.  In versions prior to 1.6 the code was duplicated in-line
5608    and the check not performed, so the filter operation completed; however,
5609    in the multi-filter case where the sum is performed the 'none' filter would
5610    be selected if all the sums overflowed, even if it wasn't in the filter
5611    list.  The fix to the first problem is simply to provide PNG_SIZE_MAX as
5612    the current lmins sum value; this means the sum can never exceed it and
5613    overflows silently.  A reasonable compiler that does choose to inline
5614    the code will simply eliminate the sum check.
5615  The fix to the second problem is to use high precision arithmetic (this is
5616    implemented in 1.7), however a simple safe fix here is to chose the lowest
5617    numbered filter in the list from png_set_filter (this only works if the
5618    first problem is also fixed) (John Bowler).
5619  Use a more efficient absolute value calculation on SSE2 (Matthieu Darbois).
5620  Fixed the case where PNG_IMAGE_BUFFER_SIZE can overflow in the application
5621    as a result of the application using an increased 'row_stride'; previously
5622    png_image_finish_read only checked for overflow on the base calculation of
5623    components.  (I.e. it checked for overflow of a 32-bit number on the total
5624    number of pixel components in the output format, not the possibly padded row
5625    length and not the number of bytes, which for linear formats is twice the
5626    number of components.)
5627  MSVC does not like '-(unsigned)', so replaced it with 0U-(unsigned)
5628  MSVC does not like (uInt) = -(unsigned) (i.e. as an initializer), unless
5629    the conversion is explicitly invoked by a cast.
5630  Put the SKIP definition in the correct place. It needs to come after the
5631    png.h include (see all the other .c files in contrib/libtests) because it
5632    depends on PNG_LIBPNG_VER.
5633  Removed the three compile warning options from the individual project
5634    files into the zlib.props globals.  It increases the warning level from 4
5635    to All and adds a list of the warnings that need to be turned off.  This is
5636    semi-documentary; the intent is to tell libpng users which warnings have
5637    been examined and judged non-fixable at present.  The warning about
5638    structure padding is fixable, but it would be a signficant change (moving
5639    structure members around).
5640
5641Version 1.6.24beta03 [July 4, 2016]
5642  Optimized absolute value calculation in filter selection, similar to
5643    code in the PAETH decoder in pngrutil.c. Build with PNG_USE_ABS to
5644    use this.
5645  Added pngcp to the build together with a pngcp.dfa configuration test.
5646  Added high resolution timing to pngcp.
5647  Added "Common linking failures" section to INSTALL.
5648  Relocated misplaced #endif in png.c sRGB profile checking.
5649  Fixed two Coverity issues in pngcp.c.
5650
5651Version 1.6.24beta04 [July 8, 2016]
5652  Avoid filter-selection heuristic sum calculations in cases where only one
5653    filter is a candidate for selection. This trades off code size (added
5654    private png_setup_*_row_only() functions) for speed.
5655
5656Version 1.6.24beta05 [July 13, 2016]
5657  Fixed some indentation to comply with our coding style.
5658  Added contrib/tools/reindent.
5659
5660Version 1.6.24beta06 [July 18, 2016]
5661  Fixed more indentation to comply with our coding style.
5662  Eliminated unnecessary tests of boolean png_isaligned() vs 0.
5663
5664Version 1.6.24rc01 [July 25, 2016]
5665  No changes.
5666
5667Version 1.6.24rc02 [August 1, 2016]
5668  Conditionally compile SSE2 headers in contrib/intel/intel_sse.patch
5669  Conditionally compile png_decompress_chunk().
5670
5671Version 1.6.24rc03 [August 2, 2016]
5672  Conditionally compile ARM_NEON headers in pngpriv.h
5673  Updated contrib/intel/intel_sse.patch
5674
5675Version 1.6.24[August 4, 2016]
5676  No changes.
5677
5678Version 1.6.25beta01 [August 12, 2016]
5679  Reject oversized iCCP profile immediately.
5680  Cleaned up PNG_DEBUG compile of pngtest.c.
5681  Conditionally compile png_inflate().
5682
5683Version 1.6.25beta02 [August 18, 2016]
5684  Don't install pngcp; it conflicts with pngcp in the pngtools package.
5685  Minor editing of INSTALL, (whitespace, added copyright line)
5686
5687Version 1.6.25rc01 [August 24, 2016]
5688  No changes.
5689
5690Version 1.6.25rc02 [August 29, 2016]
5691  Added MIPS support (Mandar Sahastrabuddhe <Mandar.Sahastrabuddhe@imgtec.com>).
5692  Only the UP filter is currently implemented.
5693
5694Version 1.6.25rc03 [August 29, 2016]
5695  Rebased contrib/intel/intel_sse.patch after the MIPS implementation.
5696
5697Version 1.6.25rc04 [August 30, 2016]
5698  Added MIPS support for SUB, AVG, and PAETH filters (Mandar Sahastrabuddhe).
5699
5700Version 1.6.25rc05 [August 30, 2016]
5701  Rebased contrib/intel/intel_sse.patch after the MIPS implementation update..
5702
5703Version 1.6.25 [September 1, 2016]
5704  No changes.
5705
5706Version 1.6.26beta01 [September 26, 2016]
5707  Fixed handling zero length IDAT in pngfix (bug report by Agostino Sarubbo,
5708    bugfix by John Bowler).
5709  Do not issue a png_error() on read in png_set_pCAL() because png_handle_pCAL
5710    has allocated memory that libpng needs to free.
5711  Conditionally compile png_set_benign_errors() in pngread.c and pngtest.c
5712  Issue a png_benign_error instead of a png_error on ADLER32 mismatch
5713    while decoding compressed data chunks.
5714  Changed PNG_ZLIB_VERNUM to ZLIB_VERNUM in pngpriv.h, pngstruct.h, and
5715    pngrutil.c.
5716  If CRC handling of critical chunks has been set to PNG_CRC_QUIET_USE,
5717    ignore the ADLER32 checksum in the IDAT chunk as well as the chunk CRCs.
5718  Issue png_benign_error() on ADLER32 checksum mismatch instead of png_error().
5719  Add tests/badcrc.png and tests/badadler.png to tests/pngtest.
5720  Merged pngtest.c with libpng-1.7.0beta84/pngtest.c
5721
5722Version 1.6.26beta02 [October 1, 2016]
5723  Updated the documentation about CRC and ADLER32 handling.
5724  Quieted 117 warnings from clang-3.8 in pngtrans.c, pngread.c,
5725     pngwrite.c, pngunknown.c, and pngvalid.c.
5726  Quieted 58 (out of 144) -Wconversion compiler warnings by changing
5727    flag definitions in pngpriv.h from 0xnnnn to 0xnnnnU and trivial changes
5728    in png.c, pngread.c, and pngwutil.c.
5729
5730Version 1.6.26beta03 [October 2, 2016]
5731  Removed contrib/libtests/*.orig and *.rej that slipped into the tarballs.
5732  Quieted the 86 remaining -Wconversion compiler warnings by
5733    revising the png_isaligned() macro and trivial changes in png.c,
5734    pngerror.c, pngget.c, pngmem.c, pngset.c, pngrtran.c, pngrutil.c,
5735    pngwtran.c, pngwrite.c, and pngwutil.c.
5736
5737Version 1.6.26beta04 [October 3, 2016]
5738  Quieted (bogus?) clang warnings about "absolute value has no effect"
5739    when PNG_USE_ABS is defined.
5740  Fixed offsets in contrib/intel/intel_sse.patch
5741
5742Version 1.6.26beta05 [October 6, 2016]
5743  Changed integer constant 4294967294 to unsigned 4294967294U in pngconf.h
5744    to avoid a signed/unsigned compare in the preprocessor.
5745
5746Version 1.6.26beta06 [October 7, 2016]
5747  Use zlib-1.2.8.1 inflateValidate() instead of inflateReset2() to
5748    optionally avoid ADLER32 evaluation.
5749
5750Version 1.6.26rc01 [October 12, 2016]
5751  No changes.
5752
5753Version 1.6.26 [October 20, 2016]
5754  Cosmetic change, "ptr != 0" to "ptr != NULL" in png.c and pngrutil.c
5755  Despammed email addresses (replaced "@" with " at ").
5756
5757Version 1.6.27beta01 [November 2, 2016]
5758  Restrict the new ADLER32-skipping to IDAT chunks.  It broke iCCP chunk
5759    handling: an erroneous iCCP chunk would throw a png_error and reject the
5760    entire PNG image instead of rejecting just the iCCP chunk with a warning,
5761    if built with zlib-1.2.8.1.
5762
5763Version 1.6.27rc01 [December 27, 2016]
5764  Control ADLER32 checking with new PNG_IGNORE_ADLER32 option. Fixes
5765    an endless loop when handling erroneous ADLER32 checksums; bug
5766    introduced in libpng-1.6.26.
5767  Removed the use of a macro containing the pre-processor 'defined'
5768    operator.  It is unclear whether this is valid; a macro that
5769    "generates" 'defined' is not permitted, but the use of the word
5770    "generates" within the C90 standard seems to imply more than simple
5771    substitution of an expression itself containing a well-formed defined
5772    operation.
5773  Added ARM support to CMakeLists.txt (Andreas Franek).
5774
5775Version 1.6.27 [December 29, 2016]
5776  Fixed a potential null pointer dereference in png_set_text_2() (bug report
5777    and patch by Patrick Keshishian, CVE-2016-10087).
5778
5779Version 1.6.28rc01 [January 3, 2017]
5780  Fixed arm/aarch64 detection in CMakeLists.txt (Gianfranco Costamagna).
5781  Added option to Cmake build allowing a custom location of zlib to be
5782    specified in a scenario where libpng is being built as a subproject
5783    alongside zlib by another project (Sam Serrels).
5784  Changed png_ptr->options from a png_byte to png_uint_32, to accomodate
5785    up to 16 options.
5786
5787Version 1.6.28rc02 [January 4, 2017]
5788  Added "include(GNUInstallDirs)" to CMakeLists.txt (Gianfranco Costamagna).
5789  Moved SSE2 optimization code into the main libpng source directory.
5790    Configure libpng with "configure --enable-intel-sse" or compile
5791    libpng with "-DPNG_INTEL_SSE" in CPPFLAGS to enable it.
5792
5793Version 1.6.28rc03 [January 4, 2017]
5794  Backed out the SSE optimization and last CMakeLists.txt to allow time for QA.
5795
5796Version 1.6.28 [January 5, 2017]
5797  No changes.
5798
5799Version 1.6.29beta01 [January 12, 2017]
5800  Readded "include(GNUInstallDirs)" to CMakeLists.txt (Gianfranco Costamagna).
5801  Moved SSE2 optimization code into the main libpng source directory.
5802    Configure libpng with "configure --enable-intel-sse" or compile
5803    libpng with "-DPNG_INTEL_SSE" in CPPFLAGS to enable it.
5804  Simplified conditional compilation in pngvalid.c, for AIX (Michael Felt).
5805
5806Version 1.6.29beta02 [February 22, 2017]
5807  Avoid conditional directives that break statements in pngrutil.c (Romero
5808    Malaquias)
5809  The contrib/examples/pngtopng.c recovery code was in the wrong "if"
5810    branches; the comments were correct.
5811  Added code for PowerPC VSX optimisation (Vadim Barkov).
5812
5813Version 1.6.29beta03 [March 1, 2017]
5814  Avoid potential overflow of shift operations in png_do_expand() (Aaron Boxer).
5815  Change test ZLIB_VERNUM >= 0x1281 to ZLIB_VERNUM >= 0x1290 in pngrutil.c
5816    because Solaris 11 distributes zlib-1.2.8.f that is older than 1.2.8.1,
5817    as suggested in zlib FAQ, item 24.
5818  Suppress clang warnings about implicit sign changes in png.c
5819
5820Version 1.6.29 [March 16, 2017]
5821  No changes.
5822
5823Version 1.6.30beta01 [April 1, 2017]
5824  Added missing "$(CPPFLAGS)" to the compile line for c.pic.o in
5825    makefile.linux and makefile.solaris-x86 (Cosmin).
5826  Revised documentation of png_get_error_ptr() in the libpng manual.
5827  Silence clang -Wcomma and const drop warnings (Viktor Szakats).
5828  Update Sourceforge URLs in documentation (https instead of http).
5829
5830Version 1.6.30beta02 [April 22, 2017]
5831  Document need to check for integer overflow when allocating a pixel
5832    buffer for multiple rows in contrib/gregbook, contrib/pngminus,
5833    example.c, and in the manual (suggested by Jaeseung Choi). This
5834    is similar to the bug reported against pngquant in CVE-2016-5735.
5835  Removed reference to the obsolete PNG_SAFE_LIMITS macro in the documentation.
5836
5837Version 1.6.30beta03 [May 22, 2017]
5838  Check for integer overflow in contrib/visupng and contrib/tools/genpng.
5839  Do not double evaluate CMAKE_SYSTEM_PROCESSOR in CMakeLists.txt.
5840  Test CMAKE_HOST_WIN32 instead of WIN32 in CMakeLists.txt.
5841  Fix some URL in documentation.
5842
5843Version 1.6.30beta04 [June 7, 2017]
5844  Avoid writing an empty IDAT when the last IDAT exactly fills the
5845    compression buffer (bug report by Brian Baird). This bug was
5846    introduced in libpng-1.6.0.
5847
5848Version 1.6.30rc01 [June 14, 2017]
5849  No changes.
5850
5851Version 1.6.30rc02 [June 25, 2017]
5852  Update copyright year in pnglibconf.h, make ltmain.sh executable.
5853  Add a reference to the libpng.download site in README.
5854
5855Version 1.6.30 [June 28, 2017]
5856  No changes.
5857
5858Version 1.6.31beta01 [July 5, 2017]
5859  Guard the definition of _POSIX_SOURCE in pngpriv.h (AIX already defines it;
5860    bug report by Michael Felt).
5861  Revised pngpriv.h to work around failure to compile arm/filter_neon.S
5862    ("typedef" directive is unrecognized by the assembler). The problem
5863    was introduced in libpng-1.6.30beta01.
5864  Added "Requires: zlib" to libpng.pc.in (Pieter Neerincx).
5865  Added special case for FreeBSD in arm/filter_neon.S (Maya Rashish).
5866
5867Version 1.6.31beta02 [July 8, 2017]
5868  Added instructions for disabling hardware optimizations in INSTALL.
5869  Added "--enable-hardware-optimizations" configuration flag to enable
5870    or disable all hardware optimizations with one flag.
5871
5872Version 1.6.31beta03 [July 9, 2017]
5873  Updated CMakeLists.txt to add INTEL_SSE and MIPS_MSA platforms.
5874  Changed "int" to "png_size_t" in intel/filter_sse2.c to prevent
5875    possible integer overflow (Bug report by John Bowler).
5876  Quieted "declaration after statement" warnings in intel/filter_sse2.c.
5877  Added scripts/makefile-linux-opt, which has hardware optimizations enabled.
5878
5879Version 1.6.31beta04 [July 11, 2017]
5880  Removed one of the GCC-7.1.0 'strict-overflow' warnings that result when
5881    integers appear on both sides of a compare.  Worked around the others by
5882    forcing the strict-overflow setting in the relevant functions to a level
5883    where they are not reported (John Bowler).
5884  Changed "FALL THROUGH" comments to "FALLTHROUGH" because GCC doesn't like
5885    the space.
5886  Worked around some C-style casts from (void*) because g++ 5.4.0 objects
5887    to them.
5888  Increased the buffer size for 'sprint' to pass the gcc 7.1.0 'sprint
5889    overflow' check that is on by default with -Wall -Wextra.
5890
5891Version 1.6.31beta05 [July 13, 2017]
5892  Added eXIf chunk support.
5893
5894Version 1.6.31beta06 [July 17, 2017]
5895  Added a minimal eXIf chunk (with Orientation and FocalLengthIn35mmFilm
5896    tags) to pngtest.png.
5897
5898Version 1.6.31beta07 [July 18, 2017]
5899  Revised the eXIf chunk in pngtest.png to fix "Bad IFD1 Directory" warning.
5900
5901Version 1.6.31rc01 [July 19, 2017]
5902  No changes.
5903
5904Version 1.6.31rc02 [July 25, 2017]
5905  Fixed typo in example.c (png_free_image should be png_image_free) (Bug
5906    report by John Smith)
5907
5908Version 1.6.31 [July 27, 2017]
5909  No changes.
5910
5911Version 1.6.32beta01 [July 31, 2017]
5912  Avoid possible NULL dereference in png_handle_eXIf when benign_errors
5913    are allowed. Avoid leaking the input buffer "eXIf_buf".
5914  Eliminated png_ptr->num_exif member from pngstruct.h and added num_exif
5915    to arguments for png_get_eXIf() and png_set_eXIf().
5916  Added calls to png_handle_eXIf(() in pngread.c and png_write_eXIf() in
5917    pngwrite.c, and made various other fixes to png_write_eXIf().
5918  Changed name of png_get_eXIF and png_set_eXIf() to png_get_eXIf_1() and
5919    png_set_eXIf_1(), respectively, to avoid breaking API compatibility
5920    with libpng-1.6.31.
5921
5922Version 1.6.32beta02 [August 1, 2017]
5923  Updated contrib/libtests/pngunknown.c with eXIf chunk.
5924
5925Version 1.6.32beta03 [August 2, 2017]
5926  Initialized btoa[] in pngstest.c
5927  Stop memory leak when returning from png_handle_eXIf() with an error
5928    (Bug report from the OSS-fuzz project).
5929
5930Version 1.6.32beta04 [August 2, 2017]
5931  Replaced local eXIf_buf with info_ptr-eXIf_buf in png_handle_eXIf().
5932  Update libpng.3 and libpng-manual.txt about eXIf functions.
5933
5934Version 1.6.32beta05 [August 2, 2017]
5935  Restored png_get_eXIf() and png_set_eXIf() to maintain API compatability.
5936
5937Version 1.6.32beta06 [August 2, 2017]
5938  Removed png_get_eXIf_1() and png_set_eXIf_1().
5939
5940Version 1.6.32beta07 [August 3, 2017]
5941  Check length of all chunks except IDAT against user limit to fix an
5942    OSS-fuzz issue (Fixes CVE-2017-12652).
5943
5944Version 1.6.32beta08 [August 3, 2017]
5945  Check length of IDAT against maximum possible IDAT size, accounting
5946    for height, rowbytes, interlacing and zlib/deflate overhead.
5947  Restored png_get_eXIf_1() and png_set_eXIf_1(), because strlen(eXIf_buf)
5948    does not work (the eXIf chunk data can contain zeroes).
5949
5950Version 1.6.32beta09 [August 3, 2017]
5951  Require cmake-2.8.8 in CMakeLists.txt. Revised symlink creation,
5952    no longer using deprecated cmake LOCATION feature (Clifford Yapp).
5953  Fixed five-byte error in the calculation of IDAT maximum possible size.
5954  
5955Version 1.6.32beta10 [August 5, 2017]
5956  Moved chunk-length check into a png_check_chunk_length() private
5957    function (Suggested by Max Stepin).
5958  Moved bad pngs from tests to contrib/libtests/crashers
5959  Moved testing of bad pngs into a separate tests/pngtest-badpngs script
5960  Added the --xfail (expected FAIL) option to pngtest.c. It writes XFAIL
5961    in the output but PASS for the libpng test.
5962  Require cmake-3.0.2 in CMakeLists.txt (Clifford Yapp).
5963  Fix "const" declaration info_ptr argument to png_get_eXIf_1() and the
5964    num_exif argument to png_get_eXIf_1() (Github Issue 171).
5965
5966Version 1.6.32beta11 [August 7, 2017]
5967  Added "eXIf" to "chunks_to_ignore[]" in png_set_keep_unknown_chunks().
5968  Added huge_IDAT.png and empty_ancillary_chunks.png to testpngs/crashers.
5969  Make pngtest --strict, --relax, --xfail options imply -m (multiple).
5970  Removed unused chunk_name parameter from png_check_chunk_length().
5971  Relocated setting free_me for eXIf data, to stop an OSS-fuzz leak.
5972  Initialize profile_header[] in png_handle_iCCP() to fix OSS-fuzz issue.
5973  Initialize png_ptr->row_buf[0] to 255 in png_read_row() to fix OSS-fuzz UMR.
5974  Attempt to fix a UMR in png_set_text_2() to fix OSS-fuzz issue.
5975  Increase minimum zlib stream from 9 to 14 in png_handle_iCCP(), to account
5976    for the minimum 'deflate' stream, and relocate the test to a point
5977    after the keyword has been read.
5978  Check that the eXIf chunk has at least 2 bytes and begins with "II" or "MM".
5979
5980Version 1.6.32rc01 [August 18, 2017]
5981  Added a set of "huge_xxxx_chunk.png" files to contrib/testpngs/crashers,
5982    one for each known chunk type, with length = 2GB-1.
5983  Check for 0 return from png_get_rowbytes() and added some (size_t) typecasts
5984    in contrib/pngminus/*.c to stop some Coverity issues (162705, 162706,
5985    and 162707).
5986  Renamed chunks in contrib/testpngs/crashers to avoid having files whose
5987    names differ only in case; this causes problems with some platforms
5988    (github issue #172).
5989
5990Version 1.6.32rc02 [August 22, 2017]
5991  Added contrib/oss-fuzz directory which contains files used by the oss-fuzz
5992    project (https://github.com/google/oss-fuzz/tree/master/projects/libpng).
5993
5994Version 1.6.32 [August 24, 2017]
5995  No changes.
5996
5997Version 1.6.33beta01 [August 28, 2017]
5998  Added PNGMINUS_UNUSED macro to contrib/pngminus/p*.c and added missing
5999    parenthesis in contrib/pngminus/pnm2png.c (bug report by Christian Hesse).
6000  Fixed off-by-one error in png_do_check_palette_indexes() (Bug report
6001    by Mick P., Source Forge Issue #269).
6002
6003Version 1.6.33beta02 [September 3, 2017]
6004  Initialize png_handler.row_ptr in contrib/oss-fuzz/libpng_read_fuzzer.cc
6005    to fix shortlived oss-fuzz issue 3234.
6006  Compute a larger limit on IDAT because some applications write a deflate
6007    buffer for each row (Bug report by Andrew Church).
6008  Use current date (DATE) instead of release-date (RDATE) in last
6009    changed date of contrib/oss-fuzz files.
6010  Enabled ARM support in CMakeLists.txt (Bernd Kuhls).
6011
6012Version 1.6.33beta03 [September 14, 2017]
6013  Fixed incorrect typecast of some arguments to png_malloc() and
6014    png_calloc() that were png_uint_32 instead of png_alloc_size_t
6015    (Bug report by "irwir" in Github libpng issue #175).
6016  Use pnglibconf.h.prebuilt when building for ANDROID with cmake (Github
6017    issue 162, by rcdailey).
6018
6019Version 1.6.33rc01 [September 20, 2017]
6020  Initialize memory allocated by png_inflate to zero, using memset, to
6021    stop an oss-fuzz "use of uninitialized value" detection in png_set_text_2()
6022    due to truncated iTXt or zTXt chunk.
6023  Initialize memory allocated by png_read_buffer to zero, using memset, to
6024    stop an oss-fuzz "use of uninitialized value" detection in
6025    png_icc_check_tag_table() due to truncated iCCP chunk.
6026  Removed a redundant test (suggested by "irwir" in Github issue #180).
6027
6028Version 1.6.33rc02 [September 23, 2017]
6029  Added an interlaced version of each file in contrib/pngsuite.
6030  Relocate new memset() call in pngrutil.c.
6031  Removed more redundant tests (suggested by "irwir" in Github issue #180).
6032  Add support for loading images with associated alpha in the Simplified
6033    API (Samuel Williams).
6034
6035Version 1.6.33 [September 28, 2017]
6036  Revert contrib/oss-fuzz/libpng_read_fuzzer.cc to libpng-1.6.32 state.
6037  Initialize png_handler.row_ptr in contrib/oss-fuzz/libpng_read_fuzzer.cc
6038  Add end_info structure and png_read_end() to the libpng fuzzer.
6039
6040Version 1.6.34 [September 29, 2017]
6041  Removed contrib/pngsuite/i*.png; some of these were incorrect and caused
6042    test failures.
6043
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6047to subscribe)
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6049
6050Glenn R-P
6051#endif