Function G_ValidateSavegame

source/core/savegamehelp.cpp:338–404

//=============================================================================

int G_ValidateSavegame(FileReader &fr, FString *savetitle, bool formenu)
{
	auto data = fr.Read();
	FSerializer arc;
	if (!arc.OpenReader((const char*)data.data(), data.size()))
	{
		return -2;
	}

	int savever;
	FString engine, gamegrp, mapgrp, title, filename, label;

	arc("Save Version", savever)
		("Engine", engine)
		("Game Resource", gamegrp)
		("Map Resource", mapgrp)
		("Title", title)
		("Map Label", label)
		("Map File", filename);

	auto savesig = gi->GetSaveSig();

	if (savetitle) *savetitle = title;
	if (engine.Compare(savesig.savesig) != 0 || savever > savesig.currentsavever)
	{
		// different engine or newer version:
		// not our business. Leave it alone.
		return 0;
	}
	SaveVersion = savesig.currentsavever;

	MapRecord *curLevel = FindMapByName(label.GetChars());

	// If the map does not exist, check if it's a user map.
	if (!curLevel)
	{
		curLevel = AllocateMap();
		if (!formenu)
		{
			curLevel->name = "";
			curLevel->SetFileName(filename.GetChars());
		}
	}
	if (!curLevel) return 0;
	if (!formenu) currentLevel = curLevel;


	if (savever < savesig.minsavever)
	{
		// old, incompatible savegame. List as not usable.
		return -1;
	}
	else
	{
		auto ggfn = ExtractFileBase(fileSystem.GetResourceFileName(1), true);
		if (gamegrp.CompareNoCase(ggfn) == 0)
		{
			return G_CheckSaveGameWads(gamegrp.GetChars(), mapgrp.GetChars(), false) ? 1 : -2;