Ticket #19986: 19986.diff

src/wp-includes/plugin.php

@@ -913 +913 @@
         static $filter_id_count = 0;
 
         if ( is_string($function) )
-                return $function;
+                return trim( $function );
 
         if ( is_object($function) ) {
                 // Closures are currently implemented as objects