diff -r 490d5cc509ed -r cf61fcea0001 wp/wp-admin/includes/class-walker-nav-menu-checklist.php
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-admin/includes/class-walker-nav-menu-checklist.php	Mon Oct 14 17:39:30 2019 +0200
@@ -0,0 +1,117 @@
+<?php
+/**
+ * Navigation Menu API: Walker_Nav_Menu_Checklist class
+ *
+ * @package WordPress
+ * @subpackage Administration
+ * @since 4.4.0
+ */
+
+/**
+ * Create HTML list of nav menu input items.
+ *
+ * @since 3.0.0
+ * @uses Walker_Nav_Menu
+ */
+class Walker_Nav_Menu_Checklist extends Walker_Nav_Menu {
+	/**
+	 *
+	 * @param array $fields
+	 */
+	public function __construct( $fields = false ) {
+		if ( $fields ) {
+			$this->db_fields = $fields;
+		}
+	}
+
+	/**
+	 * Starts the list before the elements are added.
+	 *
+	 * @see Walker_Nav_Menu::start_lvl()
+	 *
+	 * @since 3.0.0
+	 *
+	 * @param string $output Used to append additional content (passed by reference).
+	 * @param int    $depth  Depth of page. Used for padding.
+	 * @param array  $args   Not used.
+	 */
+	public function start_lvl( &$output, $depth = 0, $args = array() ) {
+		$indent = str_repeat( "\t", $depth );
+		$output .= "\n$indent<ul class='children'>\n";
+	}
+
+	/**
+	 * Ends the list of after the elements are added.
+	 *
+	 * @see Walker_Nav_Menu::end_lvl()
+	 *
+	 * @since 3.0.0
+	 *
+	 * @param string $output Used to append additional content (passed by reference).
+	 * @param int    $depth  Depth of page. Used for padding.
+	 * @param array  $args   Not used.
+	 */
+	public function end_lvl( &$output, $depth = 0, $args = array() ) {
+		$indent = str_repeat( "\t", $depth );
+		$output .= "\n$indent</ul>";
+	}
+
+	/**
+	 * Start the element output.
+	 *
+	 * @see Walker_Nav_Menu::start_el()
+	 *
+	 * @since 3.0.0
+	 *
+	 * @global int $_nav_menu_placeholder
+	 *
+	 * @param string $output Used to append additional content (passed by reference).
+	 * @param object $item   Menu item data object.
+	 * @param int    $depth  Depth of menu item. Used for padding.
+	 * @param array  $args   Not used.
+	 * @param int    $id     Not used.
+	 */
+	public function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {
+		global $_nav_menu_placeholder;
+
+		$_nav_menu_placeholder = ( 0 > $_nav_menu_placeholder ) ? intval($_nav_menu_placeholder) - 1 : -1;
+		$possible_object_id = isset( $item->post_type ) && 'nav_menu_item' == $item->post_type ? $item->object_id : $_nav_menu_placeholder;
+		$possible_db_id = ( ! empty( $item->ID ) ) && ( 0 < $possible_object_id ) ? (int) $item->ID : 0;
+
+		$indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';
+
+		$output .= $indent . '<li>';
+		$output .= '<label class="menu-item-title">';
+		$output .= '<input type="checkbox" class="menu-item-checkbox';
+
+		if ( ! empty( $item->front_or_home ) )
+			$output .= ' add-to-top';
+
+		$output .= '" name="menu-item[' . $possible_object_id . '][menu-item-object-id]" value="'. esc_attr( $item->object_id ) .'" /> ';
+
+		if ( ! empty( $item->label ) ) {
+			$title = $item->label;
+		} elseif ( isset( $item->post_type ) ) {
+			/** This filter is documented in wp-includes/post-template.php */
+			$title = apply_filters( 'the_title', $item->post_title, $item->ID );
+			if ( ! empty( $item->front_or_home ) && _x( 'Home', 'nav menu home label' ) !== $title )
+				$title = sprintf( _x( 'Home: %s', 'nav menu front page title' ), $title );
+		}
+
+		$output .= isset( $title ) ? esc_html( $title ) : esc_html( $item->title );
+ 		$output .= '</label>';
+
+		// Menu item hidden fields
+		$output .= '<input type="hidden" class="menu-item-db-id" name="menu-item[' . $possible_object_id . '][menu-item-db-id]" value="' . $possible_db_id . '" />';
+		$output .= '<input type="hidden" class="menu-item-object" name="menu-item[' . $possible_object_id . '][menu-item-object]" value="'. esc_attr( $item->object ) .'" />';
+		$output .= '<input type="hidden" class="menu-item-parent-id" name="menu-item[' . $possible_object_id . '][menu-item-parent-id]" value="'. esc_attr( $item->menu_item_parent ) .'" />';
+		$output .= '<input type="hidden" class="menu-item-type" name="menu-item[' . $possible_object_id . '][menu-item-type]" value="'. esc_attr( $item->type ) .'" />';
+		$output .= '<input type="hidden" class="menu-item-title" name="menu-item[' . $possible_object_id . '][menu-item-title]" value="'. esc_attr( $item->title ) .'" />';
+		$output .= '<input type="hidden" class="menu-item-url" name="menu-item[' . $possible_object_id . '][menu-item-url]" value="'. esc_attr( $item->url ) .'" />';
+		$output .= '<input type="hidden" class="menu-item-target" name="menu-item[' . $possible_object_id . '][menu-item-target]" value="'. esc_attr( $item->target ) .'" />';
+		$output .= '<input type="hidden" class="menu-item-attr_title" name="menu-item[' . $possible_object_id . '][menu-item-attr_title]" value="'. esc_attr( $item->attr_title ) .'" />';
+		$output .= '<input type="hidden" class="menu-item-classes" name="menu-item[' . $possible_object_id . '][menu-item-classes]" value="'. esc_attr( implode( ' ', $item->classes ) ) .'" />';
+		$output .= '<input type="hidden" class="menu-item-xfn" name="menu-item[' . $possible_object_id . '][menu-item-xfn]" value="'. esc_attr( $item->xfn ) .'" />';
+	}
+
+} // Walker_Nav_Menu_Checklist