summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--src/town_cmd.cpp2
1 files changed, 1 insertions, 1 deletions
diff --git a/src/town_cmd.cpp b/src/town_cmd.cpp
index 4d5ce792a..b6cd19bc2 100644
--- a/src/town_cmd.cpp
+++ b/src/town_cmd.cpp
@@ -1317,7 +1317,7 @@ static int GrowTownAtRoad(Town *t, TileIndex tile)
/* Exclude the source position from the bitmask
* and return if no more road blocks available */
- cur_rb &= ~DiagDirToRoadBits(ReverseDiagDir(target_dir));
+ if (IsValidDiagDirection(target_dir)) cur_rb &= ~DiagDirToRoadBits(ReverseDiagDir(target_dir));
if (cur_rb == ROAD_NONE) {
return _grow_town_result;
}