(svn r23885) -Codechange: Use the GRF sprite loader for then mapgen sprites as well.

src/landscape.cpp

@@ -769,6 +769,7 @@ static void GenerateTerrain(int type, uint flag)
 	uint32 r = Random();
 
 	const Sprite *templ = GetSprite((((r >> 24) * _genterrain_tbl_1[type]) >> 8) + _genterrain_tbl_2[type] + 4845, ST_MAPGEN);
+	if (templ == NULL) usererror("Map generator sprites could not be loaded");
 
 	uint x = r & MapMaxX();
 	uint y = (r >> MapLogX()) & MapMaxY();