diff --git a/wp-includes/nav-menu-template.php b/wp-includes/nav-menu-template.php
index d8bdaf644..35f28bb19 100644
--- a/wp-includes/nav-menu-template.php
+++ b/wp-includes/nav-menu-template.php
@@ -71,11 +71,15 @@ class Walker_Nav_Menu extends Walker {
$class_names = $value = '';
$classes = empty( $item->classes ) ? array() : (array) $item->classes;
+ $classes[] = 'menu-item-' . $item->ID;
$class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item ) );
$class_names = ' class="' . esc_attr( $class_names ) . '"';
- $output .= $indent . '
';
$attributes = ! empty( $item->attr_title ) ? ' title="' . esc_attr( $item->attr_title ) .'"' : '';
$attributes .= ! empty( $item->target ) ? ' target="' . esc_attr( $item->target ) .'"' : '';
@@ -437,7 +441,7 @@ function _wp_menu_item_classes_by_context( &$menu_items ) {
* Retrieve the HTML list content for nav menu items.
*
* @uses Walker_Nav_Menu to create HTML list content.
- * @since 2.1.0
+ * @since 3.0.0
* @see Walker::walk() for parameters and return description.
*/
function walk_nav_menu_tree( $items, $depth, $r ) {
@@ -447,4 +451,19 @@ function walk_nav_menu_tree( $items, $depth, $r ) {
return call_user_func_array( array(&$walker, 'walk'), $args );
}
+/**
+ * Prevents a menu item ID from being used more than once.
+ *
+ * @since 3.0.1
+ * @access private
+ */
+function _nav_menu_item_id_use_once( $id, $item ) {
+ static $_used_ids = array();
+ if ( in_array( $item->ID, $_used_ids ) )
+ return '';
+ $_used_ids[] = $item->ID;
+ return $id;
+}
+add_filter( 'nav_menu_item_id', '_nav_menu_item_id_use_once', 10, 2 );
+
?>