Issue 4683 - URL Fixer breaks location bar input when disabled

lib/typoAppIntegration.js

 /*
  * This file is part of the URL Fixer,
  * Copyright (C) 2006-2016 Eyeo GmbH
  *
  * URL Fixer 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.
  *
  * URL Fixer is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 98 matching lines @@
 
     exports.getURLBar = (window) => "gURLBar" in window ? window.gURLBar : null;
 
     exports.getBrowser = (window) => "gBrowser" in window ? window.gBrowser : null;
 
     exports.applyToWindow = function(window, corrector)
     {
       let urlbar = exports.getURLBar(window);
       if (urlbar && urlbar.handleCommand && !functionHooks.has(window))
       {
+        if (!urlbar.hasOwnProperty("handleCommand"))
+          urlbar = Object.getPrototypeOf(urlbar);
+
         // Handle new URLs being entered
         let unhook = hook(urlbar, "handleCommand", function()
         {
           let correction = corrector(window, urlbar.value);
           if (correction)
             urlbar.value = correction;
         });
         functionHooks.set(window, unhook);
       }
     };
@@ skipping 240 matching lines @@
     };
 
     break;
   }
   default:
   {
     exports.isKnownWindow = (window) => false;
     break;
   }
 }