Function CmdRemoveSingleRail

src/rail_cmd.cpp:612–749

* Remove a single piece of track * @param flags operation to perform * @param tile tile to remove track from * @param track rail orientation * @return the cost of this operation or an error */

 * @return the cost of this operation or an error
 */
CommandCost CmdRemoveSingleRail(DoCommandFlags flags, TileIndex tile, Track track)
{
	CommandCost cost(EXPENSES_CONSTRUCTION);
	bool crossing = false;

	if (!ValParamTrackOrientation(track)) return CMD_ERROR;
	TrackBits trackbit = TrackToTrackBits(track);

	/* Need to read tile owner now because it may change when the rail is removed
	 * Also, in case of floods, _current_company != owner
	 * There may be invalid tiletype even in exec run (when removing long track),
	 * so do not call GetTileOwner(tile) in any case here */
	Owner owner = INVALID_OWNER;

	Train *v = nullptr;

	switch (GetTileType(tile)) {
		case MP_ROAD: {
			if (!IsLevelCrossing(tile) || GetCrossingRailBits(tile) != trackbit) return CommandCost(STR_ERROR_THERE_IS_NO_RAILROAD_TRACK);

			if (_current_company != OWNER_WATER) {
				CommandCost ret = CheckTileOwnership(tile);
				if (ret.Failed()) return ret;
			}

			if (!flags.Test(DoCommandFlag::Bankrupt)) {
				CommandCost ret = EnsureNoVehicleOnGround(tile);
				if (ret.Failed()) return ret;
			}

			cost.AddCost(RailClearCost(GetRailType(tile)));

			if (flags.Test(DoCommandFlag::Execute)) {
				UpdateAdjacentLevelCrossingTilesOnLevelCrossingRemoval(tile, GetCrossingRoadAxis(tile));

				if (HasReservedTracks(tile, trackbit)) {
					v = GetTrainForReservation(tile, track);
					if (v != nullptr) FreeTrainTrackReservation(v);
				}

				owner = GetTileOwner(tile);
				Company::Get(owner)->infrastructure.rail[GetRailType(tile)] -= LEVELCROSSING_TRACKBIT_FACTOR;
				DirtyCompanyInfrastructureWindows(owner);
				MakeRoadNormal(tile, GetCrossingRoadBits(tile), GetRoadTypeRoad(tile), GetRoadTypeTram(tile), GetTownIndex(tile), GetRoadOwner(tile, RTT_ROAD), GetRoadOwner(tile, RTT_TRAM));
				DeleteNewGRFInspectWindow(GSF_RAILTYPES, tile.base());
			}
			break;
		}

		case MP_RAILWAY: {
			TrackBits present;
			/* There are no rails present at depots. */
			if (!IsPlainRail(tile)) return CommandCost(STR_ERROR_THERE_IS_NO_RAILROAD_TRACK);

			if (_current_company != OWNER_WATER) {
				CommandCost ret = CheckTileOwnership(tile);
				if (ret.Failed()) return ret;
			}