Fixes 4065 - Subscription links on Chrome 30

subscriptionLink.postload.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 25 matching lines @@
     // Search the link associated with the click
     var link = event.target;
     while (!(link instanceof HTMLAnchorElement))
     {
       link = link.parentNode;
 
       if (!link)
         return;
     }
 
+    let queryString = null;
     if (link.protocol == "http:" || link.protocol == "https:")
     {
-      if (link.host != "subscribe.adblockplus.org" || link.pathname != "/")
-        return;
+      if (link.host == "subscribe.adblockplus.org" && link.pathname == "/")
+        queryString = link.search.substr(1);
     }
-    else if (!/^abp:\/*subscribe\/*\?/i.test(link.href))
+    else
+    {
+      // Old versions of Chrome (30) don't populate the "search" property for
+      // links with non-standard URL schemes so we need to extract the query
+      // string manually.
+      let match = /^abp:\/*subscribe\/*\?(.*)/i.exec(link.href);
+      if (match)
+        queryString = match[1];
+    }
+
+    if (!queryString)
       return;
 
     // This is our link - make sure the browser doesn't handle it
     event.preventDefault();
     event.stopPropagation();
 
-    // Decode URL parameters (Note: Old versions of Chrome (30) don't populate
-    // link.search here so we have to grab the search part of the URL manually.)
-    var params = link.href.substr(link.href.indexOf("?") + 1).split("&");
+    // Decode URL parameters
+    var params = queryString.split("&");
     var title = null;
     var url = null;
     for (var i = 0; i < params.length; i++)
     {
       var parts = params[i].split("=", 2);
       if (parts.length != 2 || !/\S/.test(parts[1]))
         continue;
       switch (parts[0])
       {
         case "title":
@@ skipping 18 matching lines @@
       return;
 
     ext.backgroundPage.sendMessage({
       type: "subscriptions.add",
       title: title,
       url: url,
       confirm: true
     });
   }, true);
 }