doh! last minute changes are not a good idea

server/src/main/java/org/elasticsearch/search/aggregations/bucket/geogrid/GeoTileUtils.java

@@ -265,7 +265,7 @@ private static double tileToLon(double xTile, double tiles) {
      * Decode a yTile into its latitude value
      */
     public static double tileToLat(int yTile, int tiles) {
-        final double lat = tileToLat(yTile, tiles);
+        final double lat = tileToLat((double) yTile, tiles);
         if (tiles < MAX_TILES_FULL_PRECISION || yTile == 0 || yTile == tiles) {
             return lat; // precise case, don't need to do more work
         }