Issue 5919 - Adjust our code to the new messaging system

adblockplus/Api.jsm

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present 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 214 matching lines @@
   },
   initCommunication: function()
   {
     initFilterListeners();
 
     EventDispatcher.instance.registerListener((event, data, callback) =>
     {
       if (!data)
       {
         callback.onError("malformed request");
+        return;
       }
 
       if (!this.filtersLoaded)
       {
         callback.onError("filters not loaded");
+        return;
       }
 
       switch (data["action"])
       {
         case "getAdblockPlusEnabled":
           callback.onSuccess({"value": this.adblockPlusEnabled});
           return;
         case "setAdblockPlusEnabled":
           if ("enable" in data)
           {
@@ skipping 62 matching lines @@
             this.whitelistSite(data["url"], data["whitelisted"]);
             callback.onSuccess({});
             return;
           }
           break;
       }
       callback.onError("malformed request");
     }, "AdblockPlus:Api");
   }
 };