Issue 3915 - Avoid listing special subscriptions

messageResponder.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 54 matching lines @@
       if (key in obj)
         result[key] = obj[key];
     }
     return result;
   }
 
   function convertSubscription(subscription)
   {
     var obj = convertObject(["disabled", "downloadStatus", "homepage",
                              "lastDownload", "title", "url"], subscription);
+    obj.isSpecial = subscription instanceof SpecialSubscription;
+    obj.isDownloadable = subscription instanceof DownloadableSubscription;
     obj.isDownloading = Synchronizer.isExecuting(subscription.url);
     return obj;
   }
 
   var convertFilter = convertObject.bind(null, ["text"]);
 
   var changeListeners = new global.ext.PageMap();
   var listenedPreferences = Object.create(null);
   var listenedFilterChanges = Object.create(null);
   var messageTypes = {
@@ skipping 317 matching lines @@
         for (var i = 0; i < subscriptions.length; i++)
         {
           var subscription = subscriptions[i];
           if (subscription instanceof DownloadableSubscription)
             Synchronizer.execute(subscription, true);
         }
         break;
     }
   });
 })(this);