Ticket #41081: 41081-custom-menu-widget-empty-notice.patch

wp-includes/widgets/class-wp-nav-menu-widget.php

@@ -153 +153 @@
 
                 $nav_menu = ! empty( $instance['nav_menu'] ) ? wp_get_nav_menu_object( $instance['nav_menu'] ) : false;
 
+                // Show notice if no menu is selected or menu is empty (admins only).
+                if ( ! $nav_menu || ! wp_get_nav_menu_items( $nav_menu->term_id ) ) {
+                        if ( current_user_can( 'edit_theme_options' ) ) {
+                                echo $args['before_widget'];
+
+                                if ( ! empty( $instance['title'] ) ) {
+                                        echo $args['before_title'] . apply_filters( 'widget_title', $instance['title'] ) . $args['after_title'];
+                                }
+
+                                echo '<p class="nav-menu-widget-notice">' .
+                                        esc_html__( 'Please select a menu or add items to the selected menu.', 'default' ) .
+                                        '</p>';
+
+                                echo $args['after_widget'];
+                        }
+                        return;
+                }
+
                 /** This filter is documented in wp-includes/widgets/class-wp-widget-pages.php */
                 $title = apply_filters( 'widget_title', $instance['title'], $instance, $this->id_base );