From b803aad5a82784f4f56e5fb62f5f32975eb4af97 Mon Sep 17 00:00:00 2001
From: Tom Payne <twpayne@gmail.com>
Date: Sat, 12 Jan 2013 16:55:36 +0100
Subject: [PATCH] Don't enqueue tiles which are not idle

---
 src/ol/tilequeue.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/ol/tilequeue.js b/src/ol/tilequeue.js
index e64662ae09..57e3a474ff 100644
--- a/src/ol/tilequeue.js
+++ b/src/ol/tilequeue.js
@@ -63,7 +63,9 @@ ol.TileQueue = function(tilePriorityFunction) {
  */
 ol.TileQueue.prototype.enqueue =
     function(tile, tileCenter, tileResolution) {
-  goog.asserts.assert(tile.getState() == ol.TileState.IDLE);
+  if (tile.getState() != ol.TileState.IDLE) {
+    return;
+  }
   var tileKey = tile.getKey();
   if (!(tileKey in this.queuedTileKeys_)) {
     var priority = this.tilePriorityFunction_(tile, tileCenter, tileResolution);