Fix 0125892: Don't crash when towns upgrade road tiles during expansion (#8651)

src/road_cmd.cpp

@@ -2291,7 +2291,7 @@ static bool CanConvertUnownedRoadType(Owner owner, RoadTramType rtt)
 }
 
 /**
- * Convert the ownership of the RoadType of the tile if applyable
+ * Convert the ownership of the RoadType of the tile if applicable
  * @param tile the tile of which convert ownership
  * @param num_pieces the count of the roadbits to assign to the new owner
  * @param owner the current owner of the RoadType
@@ -2428,11 +2428,9 @@ CommandCost CmdConvertRoad(TileIndex tile, DoCommandFlag flags, uint32 p1, uint3
 			cost.AddCost(num_pieces * RoadConvertCost(from_type, to_type));
 
 			if (flags & DC_EXEC) { // we can safely convert, too
-				/* Update the company infrastructure counters. */
+				/* Call ConvertRoadTypeOwner() to update the company infrastructure counters. */
 				if (owner == _current_company) {
-					Company * c = Company::Get(_current_company);
-					c->infrastructure.road[from_type] -= num_pieces;
-					c->infrastructure.road[to_type] += num_pieces;
+					ConvertRoadTypeOwner(tile, num_pieces, owner, from_type, to_type);
 				}
 
 				/* Perform the conversion */