GRIM: Add minor versioning of savegames, allowing compatible save versions.

Bump savegame version to 22.0.

engines/grim/detection.cpp

@@ -462,7 +462,7 @@ SaveStateList GrimMetaEngine::listSaves(const char *target) const {
 		if (slotNum >= 0) {
 			SaveGame *savedState = SaveGame::openForLoading(*file);
 			if (savedState) {
-				if (savedState->saveVersion() != SaveGame::SAVEGAME_VERSION) {
+				if (!savedState->isCompatible()) {
 					delete savedState;
 					continue;
 				}

engines/grim/grim.cpp

@@ -746,7 +746,7 @@ void GrimEngine::savegameRestore() {
 		filename = _savegameFileName;
 	}
 	_savedState = SaveGame::openForLoading(filename);
-	if (!_savedState || _savedState->saveVersion() != SaveGame::SAVEGAME_VERSION)
+	if (!_savedState || !_savedState->isCompatible())
 		return;
 	g_imuse->stopAllSounds();
 	g_imuse->resetState();

engines/grim/lua_v1.cpp

@@ -866,7 +866,7 @@ void Lua_V1::GetSaveGameImage() {
 	}
 	const char *filename = lua_getstring(param);
 	SaveGame *savedState = SaveGame::openForLoading(filename);
-	if (!savedState || savedState->saveVersion() != SaveGame::SAVEGAME_VERSION) {
+	if (!savedState || !savedState->isCompatible()) {
 		lua_pushnil();
 		return;
 	}
@@ -924,7 +924,7 @@ void Lua_V1::GetSaveGameData() {
 	SaveGame *savedState = SaveGame::openForLoading(filename);
 	lua_Object result = lua_createtable();
 
-	if (!savedState || savedState->saveVersion() != SaveGame::SAVEGAME_VERSION) {
+	if (!savedState || !savedState->isCompatible()) {
 		lua_pushobject(result);
 		lua_pushnumber(2);
 		lua_pushstring("mo.set"); // Just a placeholder to not make it throw a lua error
@@ -934,7 +934,7 @@ void Lua_V1::GetSaveGameData() {
 		if (!savedState) {
 			warning("Savegame %s is invalid", filename);
 		} else {
-			warning("Savegame %s is incompatible with this Residual build. Save version: %d; current version: %d", filename, savedState->saveVersion(), SaveGame::SAVEGAME_VERSION);
+			warning("Savegame %s is incompatible with this Residual build. Save version: %d; current version: %d", filename, savedState->saveMajorVersion(), SaveGame::SAVEGAME_MAJOR_VERSION);
 		}
 		delete savedState;
 		return;

engines/grim/savegame.cpp

@@ -33,7 +33,8 @@ namespace Grim {
 #define SAVEGAME_HEADERTAG	'RSAV'
 #define SAVEGAME_FOOTERTAG	'ESAV'
 
-int SaveGame::SAVEGAME_VERSION = 21;
+uint SaveGame::SAVEGAME_MAJOR_VERSION = 22;
+uint SaveGame::SAVEGAME_MINOR_VERSION = 0;
 
 SaveGame *SaveGame::openForLoading(const Common::String &filename) {
 	Common::InSaveFile *inSaveFile = g_system->getSavefileManager()->openForLoading(filename);
@@ -52,7 +53,8 @@ SaveGame *SaveGame::openForLoading(const Common::String &filename) {
 		delete save;
 		return NULL;
 	}
-	save->_version = inSaveFile->readUint32BE();
+	save->_majorVersion = inSaveFile->readUint32BE();
+	save->_minorVersion = inSaveFile->readUint32BE();
 
 	return save;
 }
@@ -70,9 +72,11 @@ SaveGame *SaveGame::openForSaving(const Common::String &filename) {
 	save->_outSaveFile = outSaveFile;
 
 	outSaveFile->writeUint32BE(SAVEGAME_HEADERTAG);
-	outSaveFile->writeUint32BE(SAVEGAME_VERSION);
+	outSaveFile->writeUint32BE(SAVEGAME_MAJOR_VERSION);
+	outSaveFile->writeUint32BE(SAVEGAME_MINOR_VERSION);
 
-	save->_version = SAVEGAME_VERSION;
+	save->_majorVersion = SAVEGAME_MAJOR_VERSION;
+	save->_minorVersion = SAVEGAME_MINOR_VERSION;
 
 	return save;
 }
@@ -95,12 +99,20 @@ SaveGame::~SaveGame() {
 	free(_sectionBuffer);
 }
 
-int SaveGame::saveVersion() const {
+bool SaveGame::isCompatible() const {
-	return _version;
+	return _majorVersion == SAVEGAME_MAJOR_VERSION;
+}
+
+uint SaveGame::saveMajorVersion() const {
+	return _majorVersion;
+}
+
+uint SaveGame::saveMinorVersion() const {
+	return _minorVersion;
 }
 
 uint32 SaveGame::beginSection(uint32 sectionTag) {
-	assert(_version == SAVEGAME_VERSION);
+	assert(_majorVersion == SAVEGAME_MAJOR_VERSION);
 
 	if (_currentSection != 0)
 		error("Tried to begin a new save game section with ending old section");

engines/grim/savegame.h

@@ -37,9 +37,24 @@ public:
 	static SaveGame *openForSaving(const Common::String &filename);
 	~SaveGame();
 
-	static int SAVEGAME_VERSION;
+	/**
+	 * Major savegame version.
+	 * If a savegame has a different major version than SAVEGAME_MAJOR_VERSION
+	 * it cannot be loaded.
+	 */
+	static uint SAVEGAME_MAJOR_VERSION;
+	/**
+	 * Minor savegame version.
+	 * A savegame with a different minor version than SAVEGAME_MINOR_VERSION and
+	 * the same major version than SAVEGAME_MAJOR_VERSION is compatible with
+	 * the current loading code.
+	 */
+	static uint SAVEGAME_MINOR_VERSION;
 
-	int saveVersion() const;
+	bool isCompatible() const;
+
+	uint saveMajorVersion() const;
+	uint saveMinorVersion() const;
 	uint32 beginSection(uint32 sectionTag);
 	void endSection();
 	uint32 getBufferPos();
@@ -70,7 +85,8 @@ public:
 protected:
 	SaveGame();
 
-	int _version;
+	uint _majorVersion;
+	uint _minorVersion;
 	bool _saving;
 	Common::InSaveFile *_inSaveFile;
 	Common::OutSaveFile *_outSaveFile;