From 590dd6f1cf726c477db3a97e8f742bf6e1a9fb07 Mon Sep 17 00:00:00 2001
From: Andreas Hocevar <andreas.hocevar@gmail.com>
Date: Mon, 9 Oct 2017 12:46:34 +0200
Subject: [PATCH] Always create a new blank image to avoid CSP violations

---
 src/ol/imagetile.js | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/ol/imagetile.js b/src/ol/imagetile.js
index ad7acec21c..139d5b0e46 100644
--- a/src/ol/imagetile.js
+++ b/src/ol/imagetile.js
@@ -61,7 +61,7 @@ ol.inherits(ol.ImageTile, ol.Tile);
 ol.ImageTile.prototype.disposeInternal = function() {
   if (this.state == ol.TileState.LOADING) {
     this.unlistenImage_();
-    this.image_.src = ol.ImageTile.blankImageUrl;
+    this.image_ = ol.ImageTile.getBlankImage();
   }
   if (this.interimTile) {
     this.interimTile.dispose();
@@ -98,7 +98,7 @@ ol.ImageTile.prototype.getKey = function() {
 ol.ImageTile.prototype.handleImageError_ = function() {
   this.state = ol.TileState.ERROR;
   this.unlistenImage_();
-  this.image_.src = ol.ImageTile.blankImageUrl;
+  this.image_ = ol.ImageTile.getBlankImage();
   this.changed();
 };
 
@@ -150,12 +150,12 @@ ol.ImageTile.prototype.unlistenImage_ = function() {
 
 
 /**
- * Data URI for a blank image.
- * @type {string}
+ * Get a 1-pixel blank image.
+ * @return {HTMLCanvasElement} Blank image.
  */
-ol.ImageTile.blankImageUrl = (function() {
+ol.ImageTile.getBlankImage = function() {
   var ctx = ol.dom.createCanvasContext2D(1, 1);
   ctx.fillStyle = 'rgba(0,0,0,0)';
   ctx.fillRect(0, 0, 1, 1);
-  return ctx.canvas.toDataURL('image/png');
-})();
+  return ctx.canvas;
+};