Issue 1428 - Disable "Block Element" on non-HTML pages

include.postload.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 461 matching lines @@
   if(!components)
     return url;
   var newPath = removeDotSegments(components[2]);
   if(newPath.length == 0)
     return components[1];
   if(newPath[0] != '/')
     newPath = '/' + newPath;
   return components[1] + newPath;
 }
 
-// Content scripts are apparently invoked on non-HTML documents, so we have to
-// check for that before doing stuff. |document instanceof HTMLDocument| check
-// will fail on some sites like planet.mozilla.org because WebKit creates
-// Document instances for XHTML documents, have to test the root element.
-if (document.documentElement instanceof HTMLElement)
+if (document instanceof HTMLDocument)
 {
   // Use a contextmenu handler to save the last element the user right-clicked on.
   // To make things easier, we actually save the DOM event.
   // We have to do this because the contextMenu API only provides a URL, not the actual
   // DOM element.
   document.addEventListener('contextmenu', function(e) {
     lastRightClickEvent = e;
   }, false);
 
   document.addEventListener("click", function(event)
@@ skipping 141 matching lines @@
             currentElement.parentNode.removeChild(currentElement);
 
           clickHide_deactivate();
         }
         break;
       default:
         sendResponse({});
         break;
     }
   });
+
+  if (window == window.top)
+    ext.backgroundPage.sendMessage({type: "report-html-page"});
 }