Ticket #37079: 37079.patch

src/wp-includes/nav-menu-template.php

@@ -96 +96 @@
                 $menu = wp_get_nav_menu_object( $locations[ $args->theme_location ] );
 
         // get the first menu that has items if we still can't find a menu
-        if ( ! $menu && !$args->theme_location ) {
+        if ( ! $menu && !$args->theme_location && empty( $menu_items ) ) {
                 $menus = wp_get_nav_menus();
                 foreach ( $menus as $menu_maybe ) {
                         if ( $menu_items = wp_get_nav_menu_items( $menu_maybe->term_id, array( 'update_post_term_cache' => false ) ) ) {
@@ -111 +111 @@
         }
 
         // If the menu exists, get its items.
-        if ( $menu && ! is_wp_error($menu) && !isset($menu_items) )
+        if ( $menu && ! is_wp_error($menu) && empty($menu_items) )
                 $menu_items = wp_get_nav_menu_items( $menu->term_id, array( 'update_post_term_cache' => false ) );
 
         /*

src/wp-includes/nav-menu.php

@@ -621 +621 @@
                 return false;
         }
 
+
+        /**
+         * Filters whether to short-circuit the navigation menu items being returned.
+         *
+         * @since 4.6.0
+         *
+         * @param array|null  $items An array of menu item post objects to short-circuit with. Default null.
+         * @param object $menu  The menu object.
+         * @param array  $args  An array of arguments used to retrieve menu item objects.
+         */
+        $items = apply_filters( 'pre_wp_get_nav_menu_items', null, $menu, $args );
+
+        if ( null !== $items ) {
+                return $items;
+        }
+
         static $fetched = array();
 
         $items = get_objects_in_term( $menu->term_id, 'nav_menu' );