Ticket #27735: 27735.patch

src/wp-includes/nav-menu.php

@@ -142 +142 @@
  * @return bool Whether location has a menu.
  */
 function has_nav_menu( $location ) {
+        global $_wp_registered_nav_menus;
+
+        if ( ! isset( $_wp_registered_nav_menus[ $location ] ) ) {
+                return false;
+        }
+
         $locations = get_nav_menu_locations();
         return ( ! empty( $locations[ $location ] ) );
 }