Changeset 65060

Timestamp:

10/30/2026 05:18:14 PM (3 days ago)

Author:

lancewillett

Message:

General: Preserve Walker hierarchy when children sort first.

When no top-level element is included, select the first element whose parent is absent from the input instead of assuming the first element is a root. Use the configured db_fields and retain the first-element fallback for cycles.

This preserves the hierarchy and depth limits when wp_list_pages() sorts descendants before their included ancestors.

Developed in: ​https://github.com/WordPress/wordpress-develop/pull/14684

Props rob-castlegate, salvatorecorsi, mukesh27.
Fixes #28801.

Location:

trunk

Files:

• src/wp-includes/class-wp-walker.php (modified) (1 diff)
• tests/phpunit/tests/post/wpListPages.php (modified) (1 diff)
• tests/phpunit/tests/walker.php (modified) (1 diff)

trunk/src/wp-includes/class-wp-walker.php

@@ -231 +231 @@
                 /*
                  * When none of the elements is top level.
-                 * Assume the first one must be root of the sub elements.
+                 * Find an element whose parent is not in the list to use as the root.
                  */
                 if ( empty( $top_level_elements ) ) {
-
+                        $id_field    = $this->db_fields['id'];
+                        $element_ids = array();
+                        foreach ( $elements as $e ) {
+                                $element_ids[ $e->$id_field ] = true;
+                        }
+
+                        // Fall back to the first element when all parents are included, as with a cycle.
                         $root = array_first( $elements );
+                        foreach ( $elements as $e ) {
+                                if ( ! isset( $element_ids[ $e->$parent_field ] ) ) {
+                                        $root = $e;
+                                        break;
+                                }
+                        }
 
                         $top_level_elements = array();

trunk/tests/phpunit/tests/post/wpListPages.php

@@ -541 +541 @@
                 );
         }
+
+        /**
+         * @ticket 28801
+         * @dataProvider data_wp_list_pages_omitted_ancestor
+         *
+         * @param int $depth Maximum depth to display.
+         */
+        public function test_wp_list_pages_preserves_hierarchy_when_menu_order_places_child_first( $depth ) {
+                $ancestor = self::factory()->post->create( array( 'post_type' => 'page' ) );
+                $parent   = self::factory()->post->create(
+                        array(
+                                'post_type'   => 'page',
+                                'post_parent' => $ancestor,
+                                'post_title'  => 'Included parent',
+                                'menu_order'  => 10,
+                        )
+                );
+                $child    = self::factory()->post->create(
+                        array(
+                                'post_type'   => 'page',
+                                'post_parent' => $parent,
+                                'post_title'  => 'Included child',
+                                'menu_order'  => 0,
+                        )
+                );
+
+                $expected = '<li class="page_item page-item-' . $parent . ' page_item_has_children"><a href="' . get_permalink( $parent ) . '">Included parent</a>';
+                if ( 1 !== $depth ) {
+                        $expected .= '<ul class=\'children\'><li class="page_item page-item-' . $child . '"><a href="' . get_permalink( $child ) . '">Included child</a></li></ul>';
+                }
+                $expected .= '</li>';
+
+                $this->assertSame(
+                        $expected,
+                        wp_list_pages(
+                                array(
+                                        'include'      => array( $parent, $child ),
+                                        'sort_column'  => 'menu_order',
+                                        'depth'        => $depth,
+                                        'echo'         => false,
+                                        'title_li'     => '',
+                                        'item_spacing' => 'discard',
+                                )
+                        )
+                );
+        }
+
+        /**
+         * Data provider for test_wp_list_pages_preserves_hierarchy_when_menu_order_places_child_first().
+         *
+         * @return array
+         */
+        public static function data_wp_list_pages_omitted_ancestor() {
+                return array(
+                        'unlimited depth' => array( 0 ),
+                        'depth one'       => array( 1 ),
+                        'depth two'       => array( 2 ),
+                );
+        }
 }

trunk/tests/phpunit/tests/walker.php

@@ -274 +274 @@
 
         /**
+         * @ticket 28801
+         * @dataProvider data_walk_without_top_level_elements
+         *
+         * @param array  $item_data Element IDs and their parent IDs.
+         * @param int    $max_depth Maximum depth to walk.
+         * @param string $expected Expected hierarchical output.
+         */
+        public function test_walk_without_top_level_elements( $item_data, $max_depth, $expected ) {
+                $items = array();
+                foreach ( $item_data as $key => $item ) {
+                        $items[ $key ] = (object) array(
+                                'id'     => $item[0],
+                                'parent' => $item[1],
+                        );
+                }
+
+                $this->assertSame( $expected, $this->walker->walk( $items, $max_depth ) );
+        }
+
+        /**
+         * Data provider for test_walk_without_top_level_elements().
+         *
+         * @return array
+         */
+        public static function data_walk_without_top_level_elements() {
+                return array(
+                        'parent first, unlimited depth'     => array(
+                                array( array( 2, 1 ), array( 3, 2 ) ),
+                                0,
+                                '<li>2<ul><li>3</li></ul></li>',
+                        ),
+                        'parent first, depth one'           => array(
+                                array( array( 2, 1 ), array( 3, 2 ) ),
+                                1,
+                                '<li>2</li>',
+                        ),
+                        'parent first, depth two'           => array(
+                                array( array( 2, 1 ), array( 3, 2 ) ),
+                                2,
+                                '<li>2<ul><li>3</li></ul></li>',
+                        ),
+                        'child first, unlimited depth'      => array(
+                                array( array( 3, 2 ), array( 2, 1 ) ),
+                                0,
+                                '<li>2<ul><li>3</li></ul></li>',
+                        ),
+                        'child first, depth one'            => array(
+                                array( array( 3, 2 ), array( 2, 1 ) ),
+                                1,
+                                '<li>2</li>',
+                        ),
+                        'child first, depth two'            => array(
+                                array( array( 3, 2 ), array( 2, 1 ) ),
+                                2,
+                                '<li>2<ul><li>3</li></ul></li>',
+                        ),
+                        'grandchild first, unlimited depth' => array(
+                                array( array( 4, 3 ), array( 3, 2 ), array( 2, 1 ) ),
+                                0,
+                                '<li>2<ul><li>3<ul><li>4</li></ul></li></ul></li>',
+                        ),
+                        'grandchild first, depth two'       => array(
+                                array( array( 4, 3 ), array( 3, 2 ), array( 2, 1 ) ),
+                                2,
+                                '<li>2<ul><li>3</li></ul></li>',
+                        ),
+                        'child sibling order is preserved'  => array(
+                                array( array( 4, 2 ), array( 3, 2 ), array( 2, 1 ) ),
+                                0,
+                                '<li>2<ul><li>4</li><li>3</li></ul></li>',
+                        ),
+                        'numeric string identifiers'        => array(
+                                array( array( '3', '2' ), array( 2, '1' ) ),
+                                0,
+                                '<li>2<ul><li>3</li></ul></li>',
+                        ),
+                        'associative input keys'            => array(
+                                array(
+                                        'child'  => array( 3, 2 ),
+                                        'parent' => array( 2, 1 ),
+                                ),
+                                0,
+                                '<li>2<ul><li>3</li></ul></li>',
+                        ),
+                        'root sibling order is preserved'   => array(
+                                array( array( 4, 2 ), array( 3, 1 ), array( 2, 1 ) ),
+                                0,
+                                '<li>3</li><li>2<ul><li>4</li></ul></li>',
+                        ),
+                );
+        }
+
+        /**
+         * @ticket 28801
+         */
+        public function test_walk_without_top_level_elements_uses_db_fields() {
+                $this->walker->db_fields = array(
+                        'id'     => 'node_id',
+                        'parent' => 'node_parent',
+                );
+
+                $items = array(
+                        (object) array(
+                                'id'          => 30,
+                                'node_id'     => 3,
+                                'node_parent' => 2,
+                        ),
+                        (object) array(
+                                'id'          => 20,
+                                'node_id'     => 2,
+                                'node_parent' => 1,
+                        ),
+                );
+
+                $this->assertSame( '<li>20<ul><li>30</li></ul></li>', $this->walker->walk( $items, 0 ) );
+        }
+
+        /**
          * @ticket 53474
          */