diff -r 5a6b6e770365 -r 68c69c656a2c web/lib/Zend/Serializer/Adapter/Json.php
--- a/web/lib/Zend/Serializer/Adapter/Json.php	Thu May 07 15:10:09 2015 +0200
+++ b/web/lib/Zend/Serializer/Adapter/Json.php	Thu May 07 15:16:02 2015 +0200
@@ -15,9 +15,9 @@
  * @category   Zend
  * @package    Zend_Serializer
  * @subpackage Adapter
- * @copyright  Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
+ * @copyright  Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
  * @license    http://framework.zend.com/license/new-bsd     New BSD License
- * @version    $Id: Json.php 24593 2012-01-05 20:35:02Z matthew $
+ * @version    $Id$
  */
 
 /** @see Zend_Serializer_Adapter_AdapterAbstract */
@@ -30,7 +30,7 @@
  * @category   Zend
  * @package    Zend_Serializer
  * @subpackage Adapter
- * @copyright  Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
+ * @copyright  Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
  * @license    http://framework.zend.com/license/new-bsd     New BSD License
  */
 class Zend_Serializer_Adapter_Json extends Zend_Serializer_Adapter_AdapterAbstract
@@ -77,17 +77,14 @@
 
         try {
             $ret = Zend_Json::decode($json, $opts['objectDecodeType']);
+        } catch (Zend_Json_Exception $e) {
+            require_once 'Zend/Serializer/Exception.php';
+            throw new Zend_Serializer_Exception('Invalid json data');
         } catch (Exception $e) {
             require_once 'Zend/Serializer/Exception.php';
             throw new Zend_Serializer_Exception('Unserialization failed by previous error', 0, $e);
         }
 
-        // json_decode returns null for invalid JSON
-        if ($ret === null && $json !== 'null') {
-            require_once 'Zend/Serializer/Exception.php';
-            throw new Zend_Serializer_Exception('Invalid json data');
-        }
-
         return $ret;
     }
 }