From d82a7e1ece5a504e5f1790f455e3e39f5618394c Mon Sep 17 00:00:00 2001
From: gorhill <rhill@raymondhill.net>
Date: Mon, 15 Aug 2016 07:52:50 -0400
Subject: [PATCH] fix #1897

---
 src/js/scriptlets/element-picker.js | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/js/scriptlets/element-picker.js b/src/js/scriptlets/element-picker.js
index 5ede51dac..2968a9756 100644
--- a/src/js/scriptlets/element-picker.js
+++ b/src/js/scriptlets/element-picker.js
@@ -327,11 +327,15 @@ var unpreview = function() {
 
 /******************************************************************************/
 
+// https://github.com/gorhill/uBlock/issues/1897
+// Ignore `data:` URI, they can't be handled by an HTTP observer.
+
 var backgroundImageURLFromElement = function(elem) {
-    var style = window.getComputedStyle(elem);
-    var bgImg = style.backgroundImage || '';
-    var matches = /^url\((["']?)([^"']+)\1\)$/.exec(bgImg);
-    return matches !== null && matches.length === 3 ? matches[2] : '';
+    var style = window.getComputedStyle(elem),
+        bgImg = style.backgroundImage || '',
+        matches = /^url\((["']?)([^"']+)\1\)$/.exec(bgImg),
+        url = matches !== null && matches.length === 3 ? matches[2] : '';
+    return url.lastIndexOf('data:', 0) === -1 ? url.slice(0, 1024) : '';
 };
 
 /******************************************************************************/