Ticket #33442: 33442.diff

src/wp-includes/widgets.php

@@ -316 +316 @@
                 $this->_set( $widget_args['number'] );
                 $instances = $this->get_settings();
 
-                if ( isset( $instances[ $this->number ] ) ) {
+                if ( array_key_exists( $this->number, $instances ) ) {
                         $instance = $instances[ $this->number ];
 
                         /**