Issue 573 - Resolve relative URLs in the beforeload handler on Safari

include.preload.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 101 matching lines @@
           if (tag == "frame")
             target.style.setProperty("visibility", "hidden", "important");
           else
             target.style.setProperty("display", "none", "important");
         }
       }
     );
   }
 }
 
+// Converts relative to absolute URL
+// e.g.: foo.swf on http://example.com/whatever/bar.html
+//  -> http://example.com/whatever/foo.swf
+function relativeToAbsoluteUrl(url)
+{
+  // If URL is already absolute, don't mess with it
+  if (!url || /^[\w\-]+:/i.test(url))
+    return url;
+
+  // Leading / means absolute path
+  // Leading // means network path
+  if (url[0] == '/')
+  {
+    if (url[1] == '/')
+      return document.location.protocol + url;
+    else
+      return document.location.protocol + "//" + document.location.host + url;
+  }
+
+  // Remove filename and add relative URL to it
+  var base = document.baseURI.match(/.+\//);
+  if (!base)
+    return document.baseURI + "/" + url;
+  return base[0] + url;
+}
+
 function init()
 {
   // Make sure this is really an HTML page, as Chrome runs these scripts on just about everything
   if (!(document.documentElement instanceof HTMLElement))
     return;
 
   document.addEventListener("error", checkCollapse, true);
   document.addEventListener("load", checkCollapse, true);
 
   var attr = document.documentElement.getAttribute("data-adblockkey");
   if (attr)
     ext.backgroundPage.sendMessage({type: "add-key-exception", token: attr});
 
   ext.backgroundPage.sendMessage({type: "get-selectors"}, setElemhideCSSRules);
 }
 
 // In Chrome 18 the document might not be initialized yet
 if (document.documentElement)
   init();
 else
   window.setTimeout(init, 0);