M CHANGES → CHANGES

@@ -62,6 +62,7 @@ - GB Audio: Fix channel 3 reset value
  - GB Audio: Fix channel 4 initial LFSR
  - GB, GBA Video: Don't call finishFrame twice in thread proxy
  - GB Audio: Fix channel 1, 2 and 4 reset timing
+ - Util: Fix wrapping edge cases in RingFIFO
 Misc:
  - GBA Timer: Use global cycles for timers
  - GBA: Extend oddly-sized ROMs to full address space (fixes mgba.io/i/722)

M src/util/ring-fifo.c → src/util/ring-fifo.c

@@ -33,8 +33,8 @@ void* end;
 	ATOMIC_LOAD(end, buffer->readPtr);
 
 	// Wrap around if we can't fit enough in here
-	if ((intptr_t) data - (intptr_t) buffer->data + length >= buffer->capacity) {
-		if (end == buffer->data) {
+	if ((uintptr_t) data - (uintptr_t) buffer->data + length >= buffer->capacity) {
+		if (end == buffer->data || end > data) {
 			// Oops! If we wrap now, it'll appear empty
 			return 0;
 		}
@@ -65,8 +65,8 @@ void* end;
 	ATOMIC_LOAD(end, buffer->writePtr);
 
 	// Wrap around if we can't fit enough in here
-	if ((intptr_t) data - (intptr_t) buffer->data + length >= buffer->capacity) {
-		if (end == data) {
+	if ((uintptr_t) data - (uintptr_t) buffer->data + length >= buffer->capacity) {
+		if (end >= data) {
 			// Oops! If we wrap now, it'll appear full
 			return 0;
 		}
@@ -78,7 +78,7 @@ if (data > end) {
 		uintptr_t bufferEnd = (uintptr_t) buffer->data + buffer->capacity;
 		remaining = bufferEnd - (uintptr_t) data;
 	} else {
-		remaining = (intptr_t) end - (intptr_t) data;
+		remaining = (uintptr_t) end - (uintptr_t) data;
 	}
 	// If the pointers touch, it's empty
 	if (remaining < length) {
@@ -87,6 +87,6 @@ }
 	if (output) {
 		memcpy(output, data, length);
 	}
-	ATOMIC_STORE(buffer->readPtr, (void*) ((intptr_t) data + length));
+	ATOMIC_STORE(buffer->readPtr, (void*) ((uintptr_t) data + length));
 	return length;
 }