From 72e9b74b3e2562b919b2d07783b785a91e9558e7 Mon Sep 17 00:00:00 2001
From: Andreas Hocevar <andreas.hocevar@gmail.com>
Date: Thu, 8 Jun 2017 15:33:53 +0200
Subject: [PATCH] Abort loading when tile is disposed

---
 src/ol/imagetile.js            |  7 ++++---
 test/spec/ol/imagetile.test.js | 17 +++++++++++++++++
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/src/ol/imagetile.js b/src/ol/imagetile.js
index 7a032bf8ce..fe9bff4aaf 100644
--- a/src/ol/imagetile.js
+++ b/src/ol/imagetile.js
@@ -31,7 +31,7 @@ ol.ImageTile = function(tileCoord, state, src, crossOrigin, tileLoadFunction) {
 
   /**
    * @private
-   * @type {Image}
+   * @type {Image|HTMLCanvasElement}
    */
   this.image_ = new Image();
   if (crossOrigin !== null) {
@@ -60,6 +60,7 @@ ol.inherits(ol.ImageTile, ol.Tile);
 ol.ImageTile.prototype.disposeInternal = function() {
   if (this.state == ol.TileState.LOADING) {
     this.unlistenImage_();
+    this.image_.src = ol.ImageTile.blankImage.toDataURL('image/png');
   }
   if (this.interimTile) {
     this.interimTile.dispose();
@@ -95,8 +96,8 @@ ol.ImageTile.prototype.getKey = function() {
  */
 ol.ImageTile.prototype.handleImageError_ = function() {
   this.state = ol.TileState.ERROR;
-  this.image_ = ol.ImageTile.blankImage;
   this.unlistenImage_();
+  this.image_ = ol.ImageTile.blankImage;
   this.changed();
 };
 
@@ -149,7 +150,7 @@ ol.ImageTile.prototype.unlistenImage_ = function() {
 
 /**
  * A blank image.
- * @type {Image}
+ * @type {HTMLCanvasElement}
  */
 ol.ImageTile.blankImage = (function() {
   var ctx = ol.dom.createCanvasContext2D(1, 1);
diff --git a/test/spec/ol/imagetile.test.js b/test/spec/ol/imagetile.test.js
index 6b6bdb5ce3..de4d59d82a 100644
--- a/test/spec/ol/imagetile.test.js
+++ b/test/spec/ol/imagetile.test.js
@@ -82,4 +82,21 @@ describe('ol.ImageTile', function() {
 
   });
 
+  describe('dispose', function() {
+
+    it('sets image src to a blank image data uri', function() {
+      var tileCoord = [0, 0, 0];
+      var state = ol.TileState.IDLE;
+      var src = 'spec/ol/data/osm-0-0-0.png';
+      var tileLoadFunction = ol.source.Image.defaultImageLoadFunction;
+      var tile = new ol.ImageTile(tileCoord, state, src, null, tileLoadFunction);
+      tile.load();
+      expect(tile.getState()).to.be(ol.TileState.LOADING);
+      tile.dispose();
+      expect(tile.getState()).to.be(ol.TileState.ABORT);
+      expect(tile.getImage().src).to.be(ol.ImageTile.blankImage.toDataURL('image/png'));
+    });
+
+  });
+
 });