Function LoadOldSaveGame

src/saveload/oldloader.cpp:234–283

typedef bool LoadOldMainProc(LoadgameState &ls);

bool LoadOldSaveGame(std::string_view file)
{
	LoadgameState ls{};

	Debug(oldloader, 3, "Trying to load a TTD(Patch) savegame");

	_bump_assert_value = 0;
	_settings_game.construction.freeform_edges = false; // disable so we can convert map array (SetTileType is still used)

	/* Open file */
	ls.file = FioFOpenFile(file, "rb", NO_DIRECTORY);

	if (!ls.file.has_value()) {
		Debug(oldloader, 0, "Cannot open file '{}'", file);
		SetSaveLoadError(STR_GAME_SAVELOAD_ERROR_FILE_NOT_READABLE);
		return false;
	}

	SavegameType type;
	std::tie(type, std::ignore) = DetermineOldSavegameTypeAndName(*ls.file);

	LoadOldMainProc *proc = nullptr;

	switch (type) {
		case SGT_TTO: proc = &LoadTTOMain; break;
		case SGT_TTD: proc = &LoadTTDMain; break;
		default:
			Debug(oldloader, 0, "Unknown savegame type; cannot be loaded");
			break;
	}

	_savegame_type = type;

	bool game_loaded;
	try {
		game_loaded = proc != nullptr && proc(ls);
	} catch (...) {
		game_loaded = false;
	}

	if (!game_loaded) {
		SetSaveLoadError(STR_GAME_SAVELOAD_ERROR_DATA_INTEGRITY_CHECK_FAILED);
		ls.file.reset();
		return false;
	}

	_pause_mode = PauseMode::SaveLoad;

	return true;
}

std::string GetOldSaveGameName(std::string_view file)
{