Ticket #28159: 28159.2.diff

src/wp-includes/post-template.php

@@ -594 +594 @@
 
                 $classes[] = 'page-id-' . $page_id;
 
-                if ( $wpdb->get_var( $wpdb->prepare("SELECT ID FROM $wpdb->posts WHERE post_parent = %d AND post_type = 'page' AND post_status = 'publish' LIMIT 1", $page_id) ) )
+                if ( get_pages( array( 'parent' => $page_id, 'number' => 1 ) ) ) {
                         $classes[] = 'page-parent';
+                }
 
                 if ( $post->post_parent ) {
                         $classes[] = 'page-child';