Issue 4020 - In Edge, rawSender.url is not always defined

chrome/ext/background.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 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 483 matching lines @@
   chrome.runtime.onMessage.addListener(function(message, rawSender, sendResponse)
   {
     var sender = {};
 
     // Add "page" and "frame" if the message was sent by a content script.
     // If sent by popup or the background page itself, there is no "tab".
     if ("tab" in rawSender)
     {
       sender.page = new Page(rawSender.tab);
       sender.frame = {
-        url: new URL(rawSender.url),
+        url: rawSender.url ? new URL(rawSender.url): '',

[Sebastian Noack, 2016/05/27 11:58:47]

I think it would be more appropriate to set URL to null rather than empty
string, given that it's not a string but an URL object otherwise.

Also, please add a comment that this is happening only on Edge when the message
has been sent from one of our pages bundled with the extension.

         get parent()
         {
           var frames = framesOfTabs[rawSender.tab.id];
 
           if (!frames)
             return null;
 
           if ("frameId" in rawSender)
           {
             // Chrome 41+
@@ skipping 85 matching lines @@
             afterTabLoaded(callback)(createdWindow.tabs[0]);
         });
       }
       else
       {
         ext.pages.open(createData.url, callback);          
       }
     }
   };
 })();