Issue 3223 - Make context menu e10s compatible in Firefox

lib/ui.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 1582 matching lines @@
     hideElement(prefix + "contributebutton", Prefs.hideContributeButton);
   },
 
   /**
    * Adds Adblock Plus menu items to the content area context menu when it shows
    * up.
    */
   fillContentContextMenu: function(/**Element*/ popup)
   {
     let window = popup.ownerDocument.defaultView;
-    if (typeof window.gContextMenuContentData != "object" ||
+    if (!window.gContextMenuContentData ||
       typeof window.gContextMenuContentData.addonInfo != "object" ||
       typeof window.gContextMenuContentData.addonInfo.adblockplus != "object")
     {
       return;
     }
 
     let items = window.gContextMenuContentData.addonInfo.adblockplus;
     let clicked = null;
     let menuItems = [];
 
@@ skipping 43 matching lines @@
       if (event.eventPhase != event.AT_TARGET)
         return;
 
       popup.removeEventListener("popuphidden", cleanUp, false);
       for (let menuItem of menuItems)
         if (menuItem.parentNode)
           menuItem.parentNode.removeChild(menuItem);
 
       for (let [id, nodeData] of items)
         if (id && id != clicked)
           Policy.deleteNodes(id);

[Erik, 2015/12/03 23:21:57]

I'm not quite sure what this piece is for.

[Wladimir Palant, 2015/12/04 12:05:10]

We are keeping a reference to the nodes in the content process - that reference
needs to be released, otherwise we are going to leak memory. Only exception is
the menu entry that was clicked, the corresponding ID has to be passed to the
filter assistant, it will then call Policy.deleteNodes() when done.

The point of the exercise: providing immediate feedback when the user adds a
filter, by hiding the element that it applies to. Yes, users need to see that
Adblock Plus did something - and not merely after a reload.

     }.bind(this);
     popup.addEventListener("popuphidden", cleanUp, false);
   },
 
   /**
    * Called when the user presses a key in the application window, reacts to our
    * shortcut keys.
    */
   onKeyPress: function(/**Event*/ event)
   {
@@ skipping 209 matching lines @@
   ["abp-command-contribute-hide", "command", UI.hideContributeButton.bind(UI)],
   ["abp-command-toggleshownotifications", "command", Notification.toggleIgnoreCategory.bind(Notification, "*", null)]
 ];
 
 onShutdown.add(function()
 {
   for (let window of UI.applicationWindows)
     if (UI.isBottombarOpen(window))
       UI.toggleBottombar(window);
 });