Do not transform tile coordinates for tileUrlFunction

src/ol/source/tilesource.js

@@ -217,8 +217,7 @@ ol.source.Tile.prototype.getTilePixelSize =
 
 
 /**
- * Handles x-axis wrapping and returns a tile coordinate transformed from the
- * internal tile scheme to the tile grid's tile scheme. When the tile coordinate
+ * Returns a tile coordinate wrapped around the x-axis. When the tile coordinate
  * is outside the resolution and extent range of the tile grid, `null` will be
  * returned.
  * @param {ol.TileCoord} tileCoord Tile coordinate.
@@ -235,8 +234,7 @@ ol.source.Tile.prototype.getTileCoordForTileUrlFunction =
   if (this.getWrapX()) {
     tileCoord = ol.tilecoord.wrapX(tileCoord, tileGrid, projection);
   }
-  return ol.tilecoord.withinExtentAndZ(tileCoord, tileGrid) ?
-      tileGrid.transformTileCoord(tileCoord) : null;
+  return ol.tilecoord.withinExtentAndZ(tileCoord, tileGrid) ? tileCoord : null;
 };