Ticket #34896: 34896.1.diff

src/wp-includes/post.php

@@ -2405 +2405 @@
                 // Point children of this page to its parent, also clean the cache of affected children.
                 $children_query = $wpdb->prepare( "SELECT * FROM $wpdb->posts WHERE post_parent = %d AND post_type = %s", $postid, $post->post_type );
                 $children = $wpdb->get_results( $children_query );
-
-                $wpdb->update( $wpdb->posts, $parent_data, $parent_where + array( 'post_type' => $post->post_type ) );
+                if ( count( $children ) ) {
+                        $wpdb->update( $wpdb->posts, $parent_data, $parent_where + array( 'post_type' => $post->post_type ) );
+                }
         }
 
         // Do raw query. wp_get_post_revisions() is filtered.

tests/phpunit/tests/post.php

@@ -1229 +1229 @@
                 $this->assertEquals(get_date_from_gmt($post['post_date_gmt']), $out->post_date);
                 $this->assertEquals($post['post_date_gmt'], $out->post_date_gmt);
         }
+
+        function test_wp_delete_post_reassign_hierarchical_post_type() {
+                $grandparent_page_id = self::factory()->post->create( array( 'post_type' => 'page' ) );
+                $parent_page_id = self::factory()->post->create( array( 'post_type' => 'page', 'post_parent' => $grandparent_page_id ) );
+                $page_id = self::factory()->post->create( array( 'post_type' => 'page', 'post_parent' => $parent_page_id ) );
+                $this->assertEquals( $parent_page_id, get_post( $page_id )->post_parent );
+                wp_delete_post( $parent_page_id, true );
+                $this->assertEquals( $grandparent_page_id, get_post( $page_id )->post_parent );
+                wp_delete_post( $grandparent_page_id, true );
+                $this->assertEquals( 0, get_post( $page_id )->post_parent );
+        }
+
 }