Ticket #16597: 16597.patch

wp-includes/functions.php

@@ -1037 +1037 @@
         if ( is_array( $data ) || is_object( $data ) )
                 return serialize( $data );
 
+        // Double serialization is required for backward compatibility.
+        // See http://core.trac.wordpress.org/ticket/12930
         if ( is_serialized( $data ) )
                 return serialize( $data );