Issue 1977 - Consider content location instead element attributes when detecting anonymous frames

include.preload.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 58 matching lines @@
   }
 }
 
 function checkSitekey()
 {
   var attr = document.documentElement.getAttribute("data-adblockkey");
   if (attr)
     ext.backgroundPage.sendMessage({type: "add-sitekey", token: attr});
 }
 
-function hasInlineURL(element, attribute)
-{
-  var value = element.getAttribute(attribute);
-  return value == null || /^\s*(javascript:|about:|$)/i.test(value);
-}
-
 function isInlineFrame(element)
 {
-  switch (element.localName)
+  var contentDocument;
+  try
   {
-    case "iframe":
-      return hasInlineURL(element, "src") || element.hasAttribute("srcdoc");
-    case "frame":
-      return hasInlineURL(element, "src");
-    case "object":
-      return hasInlineURL(element, "data") && element.contentDocument;
-    default:
-      return false;
+    contentDocument = element.contentDocument;
   }
+  catch (e)
+  {
+    return false;  // third-party
+  }
+
+  if (!contentDocument)
+    return false;  // not a frame
+
+  return contentDocument.location.protocol == "about:";

[kzar, 2015/02/09 16:52:11]

Previously we would return true if the URL started with "javascript:" or
"about:" but now we're only checking if the protocol is about. What about
Javascript URLs?

[Sebastian Noack, 2015/02/09 17:10:00]

Previously, we checked against the raw attribute value and had to consider
javascript: URLs explicitly. However, this isn't necessary anymore, since actual
URL of a page loaded from a javascript: URL is "about:blank".

 }
 
 function resolveURL(url)
 {
   var a = document.createElement("a");
   a.href = url;
   return a.href;
 }
 
 function reinjectRulesWhenRemoved(document, style)
@@ skipping 165 matching lines @@
   }, true);
 
   ext.backgroundPage.sendMessage({type: "get-selectors"}, setElemhideCSSRules);
 }
 
 if (document instanceof HTMLDocument)
 {
   checkSitekey();
   init(document);
 }