Ticket #31690: 31690.diff

src/wp-includes/default-widgets.php

@@ -533 +533 @@
                         $instance['text'] =  $new_instance['text'];
                 else
                         $instance['text'] = stripslashes( wp_filter_post_kses( addslashes($new_instance['text']) ) ); // wp_filter_post_kses() expects slashed
-                $instance['filter'] = isset($new_instance['filter']);
+                $instance['filter'] = ! empty( $new_instance['filter'] );
                 return $instance;
         }