Merge pull request #160 from killme2008/master

Fixed undefined in FriendShipQuery.

Author: wangxiao

lib/query.js

@@ -922,12 +922,16 @@ module.exports = function(AV) {
       return new AV.User();
     },
      _processResult: function(json){
-      var user = json[this._friendshipTag];
-      if(user.__type === 'Pointer' && user.className === '_User'){
-        delete user.__type;
-        delete user.className;
-      }
-      return user;
+       if(json && json[this._friendshipTag]) {
+         var user = json[this._friendshipTag];
+         if(user.__type === 'Pointer' && user.className === '_User'){
+           delete user.__type;
+           delete user.className;
+          }
+          return user;
+       } else {
+         return null;
+       }
     },
    });
 };