(svn r14743) -Codechange: use INVALID_TILE to indicate station doesn't have queried facility (or station/roadstop is invalid) instead of 0 (Yexo)

src/station_gui.cpp

@@ -338,7 +338,7 @@ public:
 			const Station *st = this->stations[i];
 			int x;
 
-			assert(st->xy != 0);
+			assert(st->xy != INVALID_TILE);
 
 			/* Do not do the complex check HasStationInUse here, it may be even false
 				* when the order had been removed and the station list hasn't been removed yet */