M CHANGES → CHANGES

@@ -16,6 +16,7 @@ - GB MBC: Fix SRAM sizes 4 and 5
  - GB Video: Fix 16-bit screenshots (fixes mgba.io/i/826)
  - GB Core: Fix palette loading when loading a foreign config
  - Qt: Fix LOG argument order
+ - GB Memory: Prevent accessing empty SRAM (fixes mgba.io/i/831)
 Misc:
  - GBA Timer: Use global cycles for timers
  - GBA: Extend oddly-sized ROMs to full address space (fixes mgba.io/i/722)

M src/gb/memory.c → src/gb/memory.c

@@ -221,7 +221,7 @@ if (memory->rtcAccess) {
 			return memory->rtcRegs[memory->activeRtcReg];
 		} else if (memory->mbcRead) {
 			return memory->mbcRead(memory, address);
-		} else if (memory->sramAccess) {
+		} else if (memory->sramAccess && memory->sram) {
 			return memory->sramBank[address & (GB_SIZE_EXTERNAL_RAM - 1)];
 		} else if (memory->mbcType == GB_HuC3) {
 			return 0x01; // TODO: Is this supposed to be the current SRAM bank?
@@ -290,7 +290,7 @@ case GB_REGION_EXTERNAL_RAM:
 	case GB_REGION_EXTERNAL_RAM + 1:
 		if (memory->rtcAccess) {
 			memory->rtcRegs[memory->activeRtcReg] = value;
-		} else if (memory->sramAccess) {
+		} else if (memory->sramAccess && memory->sram) {
 			memory->sramBank[address & (GB_SIZE_EXTERNAL_RAM - 1)] = value;
 		} else {
 			memory->mbcWrite(gb, address, value);
@@ -388,7 +388,7 @@ case GB_REGION_EXTERNAL_RAM + 1:
 		if (memory->rtcAccess) {
 			return memory->rtcRegs[memory->activeRtcReg];
 		} else if (memory->sramAccess) {
-			if (segment < 0) {
+			if (segment < 0 && memory->sram) {
 				return memory->sramBank[address & (GB_SIZE_EXTERNAL_RAM - 1)];
 			} else if ((size_t) segment * GB_SIZE_EXTERNAL_RAM < gb->sramSize) {
 				return memory->sram[(address & (GB_SIZE_EXTERNAL_RAM - 1)) + segment *GB_SIZE_EXTERNAL_RAM];