M CHANGES → CHANGES

@@ -3,6 +3,7 @@ Bugfixes:
  - GBA Memory: Fix misaligned BIOS reads
  - GBA BIOS: Fix MidiKey2Freq BIOS reads
  - GBA BIOS: Fix invalid CpuSet not setting BIOS prefetch
+ - GB MBC: Fix SRAM dangling pointer with RTC games
 
 0.5.1: (2016-10-05)
 Bugfixes:

M src/gb/gb.c → src/gb/gb.c

@@ -120,7 +120,7 @@
 static void GBSramDeinit(struct GB* gb) {
 	if (gb->sramVf) {
 		gb->sramVf->unmap(gb->sramVf, gb->memory.sram, gb->sramSize);
-		if (gb->memory.mbcType == GB_MBC3_RTC) {
+		if (gb->memory.mbcType == GB_MBC3_RTC && gb->sramVf == gb->sramRealVf) {
 			GBMBCRTCWrite(gb);
 		}
 		gb->sramVf = NULL;
@@ -192,7 +192,7 @@ }
 
 void GBSramClean(struct GB* gb, uint32_t frameCount) {
 	// TODO: Share with GBASavedataClean
-	if (!gb->sramVf) {
+	if (!gb->sramVf || gb->sramVf != gb->sramRealVf) {
 		return;
 	}
 	if (gb->sramDirty & GB_SRAM_DIRT_NEW) {

M src/gb/mbc.c → src/gb/mbc.c

@@ -671,6 +671,15 @@ STORE_32LE(gb->memory.rtcRegs[3], 0, &rtcBuffer.latchedDays);
 	STORE_32LE(gb->memory.rtcRegs[4], 0, &rtcBuffer.latchedDaysHi);
 	STORE_64LE(rtcLastLatch, 0, &rtcBuffer.unixTime);
 
+	if (vf->size(vf) == gb->sramSize) {
+		// Writing past the end of the file can invalidate the file mapping
+		vf->unmap(vf, gb->memory.sram, gb->sramSize);
+		gb->memory.sram = NULL;
+	}
 	vf->seek(vf, gb->sramSize, SEEK_SET);
 	vf->write(vf, &rtcBuffer, sizeof(rtcBuffer));
+	if (!gb->memory.sram) {
+		gb->memory.sram = vf->map(vf, gb->sramSize, MAP_WRITE);
+		GBMBCSwitchSramBank(gb, gb->memory.sramCurrentBank);
+	}
 }