diff options
| -rw-r--r-- | src/road_cmd.cpp | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/src/road_cmd.cpp b/src/road_cmd.cpp index 0d286cb66..96f2b0b5c 100644 --- a/src/road_cmd.cpp +++ b/src/road_cmd.cpp @@ -499,12 +499,21 @@ CommandCost CmdBuildRoad(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 if (ret.Failed()) return ret; } - CommandCost ret = EnsureNoVehicleOnGround(tile); - if (ret.Failed()) return ret; + DisallowedRoadDirections dis_existing = GetDisallowedRoadDirections(tile); + DisallowedRoadDirections dis_new = dis_existing ^ toggle_drd; + + /* We allow removing disallowed directions to break up + * deadlocks, but adding them can break articulated + * vehicles. As such, only when less is disallowed, + * i.e. bits are removed, we skip the vehicle check. */ + if (CountBits(dis_existing) <= CountBits(dis_new)) { + CommandCost ret = EnsureNoVehicleOnGround(tile); + if (ret.Failed()) return ret; + } /* Ignore half built tiles */ if ((flags & DC_EXEC) && rt != ROADTYPE_TRAM && IsStraightRoad(existing)) { - SetDisallowedRoadDirections(tile, GetDisallowedRoadDirections(tile) ^ toggle_drd); + SetDisallowedRoadDirections(tile, dis_new); MarkTileDirtyByTile(tile); } return CommandCost(); |