Check that tile area is valid in CmdBuildRailStation

src/station_cmd.cpp

@@ -1333,6 +1333,9 @@ CommandCost CmdBuildRailStation(TileIndex tile_org, DoCommandFlag flags, uint32
 		w_org = numtracks;
 	}
 
+	/* Check if the first tile and the last tile are valid */
+	if (!IsValidTile(tile_org) || TileAddWrap(tile_org, w_org - 1, h_org - 1) == INVALID_TILE) return CMD_ERROR;
+
 	bool reuse = (station_to_join != NEW_STATION);
 	if (!reuse) station_to_join = INVALID_STATION;
 	bool distant_join = (station_to_join != INVALID_STATION);