More improvements to ISO detection

Core/System.cpp

@@ -340,7 +340,7 @@ static bool CPU_Init(FileLoader *fileLoader, IdentifiedFileType type, std::strin
 		// Trying to boot other things lands us here. We need to return a sensible error string.
 		ERROR_LOG(Log::Loader, "CPU_Init didn't recognize file. %s", errorString->c_str());
 		auto sy = GetI18NCategory(I18NCat::SYSTEM);
-		*errorString = sy->T("Not a PSP game");  // best string we have.
+		*errorString = ApplySafeSubstitutions("%1 (%2)", sy->T("Not a PSP game"), *errorString);  // best string we have.
 		return false;
 	}
 	}
@@ -616,14 +616,13 @@ bool PSP_InitStart(const CoreParameter &coreParam) {
 		NOTICE_LOG(Log::Boot, "PPSSPP %s", PPSSPP_GIT_VERSION);
 
 		Path filename = g_CoreParameter.fileToStart;
-		FileLoader *loadedFile = ResolveFileLoaderTarget(ConstructFileLoader(filename));
 
-		IdentifiedFileType type = Identify_File(loadedFile, &g_CoreParameter.errorString);
-		g_CoreParameter.fileType = type;
+		IdentifiedFileType fileType;
+		FileLoader *loadedFile = ResolveFileLoaderTarget(ConstructFileLoader(filename), &fileType, error_string);
 
 		if (System_GetPropertyBool(SYSPROP_ENOUGH_RAM_FOR_FULL_ISO)) {
 			if (g_Config.bCacheFullIsoInRam) {
-				switch (g_CoreParameter.fileType) {
+				switch (fileType) {
 				case IdentifiedFileType::PSP_ISO:
 				case IdentifiedFileType::PSP_ISO_NP:
 					loadedFile = new RamCachingFileLoader(loadedFile);
@@ -635,9 +634,11 @@ bool PSP_InitStart(const CoreParameter &coreParam) {
 			}
 		}
 
+		g_CoreParameter.fileType = fileType;
+
 		// TODO: The reason we pass in g_CoreParameter.errorString here is that it's persistent -
 		// it gets written to from the loader thread that gets spawned.
-		if (!CPU_Init(loadedFile, type, &g_CoreParameter.errorString)) {
+		if (!CPU_Init(loadedFile, fileType, &g_CoreParameter.errorString)) {
 			CPU_Shutdown(false);
 			g_CoreParameter.fileToStart.clear();
 			*error_string = g_CoreParameter.errorString;