Issue 1396 - Avoid infinite recursion when collapsing <input type="image"> elements

include.preload.js

 /*
  * This file is part of Adblock Plus <http://adblockplus.org/>,
  * Copyright (C) 2006-2014 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 29 matching lines @@
       {
         type: "should-collapse",
         url: url,
         mediatype: typeMap[tag]
       },
 
       function(response)
       {
         if (response && element.parentNode)
         {
+          var property = "display";
+          var value = "none";
+
           // <frame> cannot be removed, doing that will mess up the frameset
           if (tag == "frame")
-            element.style.setProperty("visibility", "hidden", "important");
-          else
-            element.style.setProperty("display", "none", "important");
+          {
+            property = "visibility";
+            value = "hidden";
+          }
+
+          // <input type="image"> elements try to load their image again
+          // when the "display" CSS property is set. So we have to check
+          // that it isn't already collapsed to avoid an infinite recursion.
+          if (element.style.getPropertyValue(property) != value ||
+              element.style.getPropertyPriority(property) != "important")
+            element.style.setProperty(property, value, "important");
         }
       }
     );
   }
 }
 
 function checkSitekey()
 {
   var attr = document.documentElement.getAttribute("data-adblockkey");
   if (attr)
@@ skipping 134 matching lines @@
   }, true);
 
   ext.backgroundPage.sendMessage({type: "get-selectors"}, setElemhideCSSRules);
 }
 
 if (document instanceof HTMLDocument)
 {
   checkSitekey();
   init(document);
 }