Issue 1724 - Fixed memory leak in messaging code, when no response is sent, on Safari

safari/ext/common.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 13 matching lines @@
     this._messageDispatcher = messageDispatcher;
     this._responseCallbacks = {__proto__: null};
     this._responseCallbackCounter = 0;
   };
   MessageProxy.prototype = {
     _sendResponse: function(request, message)
     {
       var response = {};
       for (var prop in request)
         response[prop] = request[prop];
-      if (typeof message != "undefined")
-        response.payload = message;
+      response.payload = message;
 
       this._messageDispatcher.dispatchMessage("response", response);
     },
     handleRequest: function(request, sender)
     {
       if ("callbackId" in request)
       {
         var sent = false;
         var sendResponse = function(message)
         {
@@ skipping 16 matching lines @@
       }
     },
     handleResponse: function(response)
     {
       var callbackId = response.callbackId;
       var callback = this._responseCallbacks[callbackId];
       if (callback)
       {
         delete this._responseCallbacks[callbackId];
 
-        if ("payload" in response)
+        if (typeof response.payload != "undefined")
           callback(response.payload);
       }
     },
     sendMessage: function(message, responseCallback, extra)
     {
       var request = {payload: message};
 
       if (responseCallback)
       {
         request.callbackId = ++this._responseCallbackCounter;
@@ skipping 129 matching lines @@
   };
 
 
   /* Utils */
 
   ext.getURL = function(path)
   {
     return safari.extension.baseURI + path;
   };
 })();