Ticket #10852: new_get_page_children.diff

src/wp-includes/post.php

@@ -4318 +4318 @@
  * @return array List of page children.
  */
 function get_page_children( $page_id, $pages ) {
-        $page_list = array();
+        $post_hash = array();
+        $children_hash = array();
+
+        // build a hash of ID -> children
         foreach ( (array) $pages as $page ) {
-                if ( $page->post_parent == $page_id ) {
-                        $page_list[] = $page;
-                        if ( $children = get_page_children( $page->ID, $pages ) ) {
-                                $page_list = array_merge( $page_list, $children );
-                        }
+                $post_hash[$page->ID] = $page;
+                if ( !array_key_exists( $page->post_parent, $children_hash ) ) {
+                        $children_hash[$page->post_parent] = [$page->ID];
+                } else {
+                        $children_hash[$page->post_parent][] = $page->ID;
                 }
         }
 
-        return $page_list;
+        if( array_key_exists( $page_id, $children_hash ) ) {
+                $post_list = array();
+                $to_look = array_reverse( $children_hash[$page_id] );
+                // while we still have posts to_look add them to the list
+                while ( $to_look ) {
+                        $id = array_pop( $to_look );
+                        $post_list[] = $post_hash[$id];
+                        if ( array_key_exists( $id, $children_hash ) ) {
+                                foreach( array_reverse( $children_hash[$id] ) as $child ) {
+                                        $to_look[] = $child;
+                                }
+                        }
+                }
+                return $post_list;
+        } else {
+                return array();
+        }
 }
 
 /**