Merge pull request #8301 from unknownbrackets/savestates

Fix iOS savestate compatibility issue

Core/FileSystems/ISOFileSystem.cpp

@@ -555,8 +555,10 @@ size_t ISOFileSystem::ReadFile(u32 handle, u8 *pointer, s64 size, int &usec)
 		if (e.isRawSector) {
 			positionOnIso = e.sectorStart * 2048ULL + e.seekPos;
 			fileSize = (s64)e.openSize;
+		} else if (e.file == nullptr) {
+			ERROR_LOG(FILESYS, "File no longer exists (loaded savestate with different ISO?)");
+			return 0;
 		} else {
-			_dbg_assert_msg_(FILESYS, e.file != 0, "Expecting non-raw fd to have a tree entry.");
 			positionOnIso = e.file->startingPosition + e.seekPos;
 			fileSize = e.file->size;
 		}

GPU/GPUCommon.cpp

@@ -1069,29 +1069,6 @@ struct DisplayList_v2 {
 	bool bboxResult;
 };
 
-struct DisplayList_v3_no_padding {
-	int id;
-	u32 startpc;
-	u32 pc;
-	u32 stall;
-	DisplayListState state;
-	SignalBehavior signal;
-	int subIntrBase;
-	u16 subIntrToken;
-	DisplayListStackEntry stack[32];
-	int stackptr;
-	bool interrupted;
-	u64 waitTicks;
-	bool interruptsEnabled;
-	bool pendingInterrupt;
-	bool started;
-	PSPPointer<u32_le> context;
-	u32 offsetAddr;
-	bool bboxResult;
-	u32 stackAddr;
-	// See the header
-};
-
 void GPUCommon::DoState(PointerWrap &p) {
 	easy_guard guard(listLock);
 
@@ -1103,21 +1080,33 @@ void GPUCommon::DoState(PointerWrap &p) {
 	if (s >= 4) {
 		p.DoArray(dls, ARRAY_SIZE(dls));
 	} else if (s >= 3) {
-#if defined(ANDROID) && defined(_M_IX86)
-		// If this starts failing, we'll need to put some alignment attributes on the Displaylist_v3_no_padding struct above.
-		static_assert(sizeof(DisplayList_v3_no_padding) == 452, "Not the old DisplayList size anymore, see comment");
-		for (size_t i = 0; i < ARRAY_SIZE(dls); ++i) {
-			DisplayList_v3_no_padding oldDL;
-			p.Do(oldDL);
-			// Copy over everything except the new padding bytes to make the struct size
-			// equal to other platforms.
-			memcpy(&dls[i], &oldDL, sizeof(DisplayList_v3_no_padding));
-			dls[i].padding = 0;
+		// This may have been saved with or without padding, depending on platform.
+		// We need to upconvert it to our consistently-padded struct.
+		static const size_t DisplayList_v3_size = 452;
+		static const size_t DisplayList_v4_size = 456;
+		static_assert(DisplayList_v4_size == sizeof(DisplayList), "Make sure to change here when updating DisplayList");
+
+		p.DoVoid(&dls[0], DisplayList_v3_size);
+		dls[0].padding = 0;
+
+		const u8 *savedPtr = *p.GetPPtr();
+		const u32 *savedPtr32 = (const u32 *)savedPtr;
+		// Here's the trick: the first member (id) is always the same as the index.
+		// The second member (startpc) is always an address, or 0, never 1.  So we can see the padding.
+		const bool hasPadding = savedPtr32[1] == 1;
+		if (hasPadding) {
+			u32 padding;
+			p.Do(padding);
+		}
+
+		for (size_t i = 1; i < ARRAY_SIZE(dls); ++i) {
+			p.DoVoid(&dls[i], DisplayList_v3_size);
+			dls[i].padding = 0;
+			if (hasPadding) {
+				u32 padding;
+				p.Do(padding);
+			}
 		}
-#else
-		// Android-x86 used to write badly padded data structures.
-		p.DoArray(dls, ARRAY_SIZE(dls));
-#endif
 	} else if (s >= 2) {
 		for (size_t i = 0; i < ARRAY_SIZE(dls); ++i) {
 			DisplayList_v2 oldDL;