Ticket #22189: 22189.diff

wp-includes/post.php

@@ -2936 +2936 @@
                 $feeds = array();
 
         $hierarchical_post_types = get_post_types( array('hierarchical' => true) );
-        if ( 'attachment' == $post_type ) {
+        if ( 'nav_menu_item' == $post_type ) {
+                return $slug;
+        } elseif ( 'attachment' == $post_type ) {
                 // Attachment slugs must be unique across all types.
                 $check_sql = "SELECT post_name FROM $wpdb->posts WHERE post_name = %s AND ID != %d LIMIT 1";
                 $post_name_check = $wpdb->get_var( $wpdb->prepare( $check_sql, $slug, $post_ID ) );