Ticket #36174: patch_draft_child_post_link.diff

wp-includes/post.php

@@ -4441 +4441 @@
 
         foreach ( $page->ancestors as $parent ) {
                 $parent = get_post( $parent );
-                if ( $parent ) {
+                if ( $parent && ! empty( $parent->post_name ) ) {
                         $uri = $parent->post_name . '/' . $uri;
                 }
         }