diff -r 5a6b6e770365 -r 68c69c656a2c web/lib/Zend/Stdlib/CallbackHandler.php
--- a/web/lib/Zend/Stdlib/CallbackHandler.php	Thu May 07 15:10:09 2015 +0200
+++ b/web/lib/Zend/Stdlib/CallbackHandler.php	Thu May 07 15:16:02 2015 +0200
@@ -14,7 +14,7 @@
  *
  * @category   Zend
  * @package    Zend_Stdlib
- * @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
  */
 
@@ -27,7 +27,7 @@
  *
  * @category   Zend
  * @package    Zend_Stdlib
- * @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_Stdlib_CallbackHandler
@@ -101,7 +101,10 @@
         }
 
         // If pecl/weakref is not installed, simply store the callback and return
-        if (!class_exists('WeakRef')) {
+        set_error_handler(array($this, 'errorHandler'), E_WARNING);
+        $callable = class_exists('WeakRef');
+        restore_error_handler();
+        if (!$callable || $this->error) {
             $this->callback = $callback;
             return;
         }