Issue 1852 - Fixed a TypeError on Safari caused by parsing empty URLs

lib/url.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
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 window.URL = (function()
 {
   let URL = window.URL || window.webkitURL;
   let URLProperties = ["href", "protocol", "host", "hostname", "port", "pathname", "search"];
 
-  if (!URL || !URLProperties.every(prop => prop in new URL("")))
+  if (!URL || !URLProperties.every(prop => prop in new URL("about:blank")))
   {
     let doc = document.implementation.createHTMLDocument();
 
     let base = doc.createElement("base");
     doc.head.appendChild(base);
 
     let anchor = doc.createElement("a");
     doc.body.appendChild(anchor);
 
     URL = function(url, baseUrl)
     {
       if (baseUrl instanceof URL)
         base.href = baseUrl.href;
       else
         base.href = baseUrl || "";
       anchor.href = url;
 
       for (let prop of URLProperties)
         this[prop] = anchor[prop];
     };
   }
 
   return URL;
 })();