(svn r22057) -Fix: waypoint conversion could (previously) silently overfill the pool and crash

src/saveload/station_sl.cpp

@@ -75,6 +75,9 @@ void MoveBuoysToWaypoints()
 		/* Delete the station, so we can make it a real waypoint. */
 		delete st;
 
+		/* Stations and waypoints are in the same pool, so if a station
+		 * is deleted there must be place for a Waypoint. */
+		assert(Waypoint::CanAllocateItem());
 		Waypoint *wp   = new (index) Waypoint(xy);
 		wp->town       = town;
 		wp->string_id  = train ? STR_SV_STNAME_WAYPOINT : STR_SV_STNAME_BUOY;

src/saveload/waypoint_sl.cpp

@@ -93,6 +93,8 @@ void MoveWaypointsToBaseStations()
 		}
 	}
 
+	if (!Waypoint::CanAllocateItem(_old_waypoints.Length())) SlError(STR_ERROR_TOO_MANY_STATIONS_LOADING);
+
 	/* All saveload conversions have been done. Create the new waypoints! */
 	for (OldWaypoint *wp = _old_waypoints.Begin(); wp != _old_waypoints.End(); wp++) {
 		Waypoint *new_wp = new Waypoint(wp->xy);