Issue 2634 - Consider alternative URLs for element collapsing

background.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2015 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 315 matching lines @@
 
       sendResponse(selectors);
       break;
     case "should-collapse":
       if (isFrameWhitelisted(sender.page, sender.frame, "DOCUMENT"))
       {
         sendResponse(false);
         break;
       }
 
-      var url = new URL(msg.url);
       var documentHost = extractHostFromFrame(sender.frame);
-      var filter = defaultMatcher.matchesAny(
-        stringifyURL(url), msg.mediatype,
-        documentHost, isThirdParty(url, documentHost)
-      );
-
-      if (filter instanceof BlockingFilter)
-      {
-        var collapse = filter.collapse;
-        if (collapse == null)
-          collapse = Prefs.hidePlaceholders;
-        sendResponse(collapse);
-      }
-      else
-        sendResponse(false);
+      var blocked = false;
+
+      for (var i = 0; i < msg.urls.length; i++)
+      {
+        var url = new URL(msg.urls[i], msg.baseURL);
+        var filter = defaultMatcher.matchesAny(
+          stringifyURL(url), msg.mediatype,
+          documentHost, isThirdParty(url, documentHost)
+        );
+
+        if (filter instanceof BlockingFilter)
+        {
+          if (filter.collapse != null)
+          {
+            sendResponse(filter.collapse);
+            return;
+          }
+
+          blocked = true;
+        }
+      }
+
+      sendResponse(blocked && Prefs.hidePlaceholders);
       break;
     case "get-domain-enabled-state":
       // Returns whether this domain is in the exclusion list.
       // The browser action popup asks us this.
       if(sender.page)
       {
         sendResponse({enabled: !isPageWhitelisted(sender.page)});
         return;
       }
       break;
@@ skipping 52 matching lines @@
       break;
   }
 });
 
 // update icon when page changes location
 ext.pages.onLoading.addListener(function(page)
 {
   page.sendMessage({type: "clickhide-deactivate"});
   refreshIconAndContextMenu(page);
 });