[wp-trac] [WordPress Trac] #14329: current_page_ancestor not being set because $post->ancestors is not being cached

Fri Jul 16 13:47:35 UTC 2010

#14329: current_page_ancestor not being set because $post->ancestors is not being
cached
--------------------------+-------------------------------------------------
 Reporter:  layotte       |       Owner:                                         
     Type:  defect (bug)  |      Status:  new                                    
 Priority:  normal        |   Milestone:  Awaiting Review                        
Component:  Cache         |     Version:  3.0                                    
 Severity:  normal        |    Keywords:  current_page_ancestor, $post->ancestors
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 I noticed a weird problem where current_page_ancestor class was not being
 attached to the appropriate <li> from a wp_list_pages on a WPMS site.

 I was running this wp_list_pages query:
 $children =
 wp_list_pages("title_li=&child_of=".$ugce."&echo=0&depth=1&sort_column=menu_order");
 //$ugce is a dynamic parent ID

 the current_page_item and current_page_parent classes are being set.
 However, when I go to a grandchild, the current_page_ancestor is not being
 set.

 I looked through core and found in classes.php (line 1192 - WP3.0) is
 calling $_current_page = get_page($current_page) and testing if
 $_current_page->ancestors is set. It isn't set (for some reason), so it
 skips to the next test.

 I went over to post.php to where get_page merely calls get_post, and
 noticed that at line 337, get_posts checks to see if the $post_id is
 already in the wp_cache:
 if ( ! $_post = wp_cache_get($post_id, 'posts') )

 I assume that the current post would be in the wp_cache, so it merely
 returns the cached results.

 That made me think that perhaps the cache does not have the ancestors in
 it. So I ran a test to find out more.

 I setup my theme to output the post ID, the post ancestors, the array from
 get_post, the array from wp_cache_get and then I cleared the wp_cache and
 ran the same output to see how it changed.

 before the wp_cache_flush(), the get_post and wp_cache_get does not
 contain the post->ancestors. After the wp_cache_flush() they both contain
 the post->ancestors.

 I suspect that there is a place where the post is being added to cache
 without the ancestors and then later when the ancestors are being check
 from the cache it returns as if there are none.

 This is my php code:

{{{
 <?php echo "Post ID: " . $post->ID; ?>
 <?php echo ' $post->ancestors: ';
 print_r($post->ancestors); ?>
 <?php $page = get_page( $post->ID ); ?>
 <?php echo " print_r get_page: "; print_r($page);
 ?>
 <?php $_page = wp_cache_get($post->ID, 'posts'); ?>
 <?php echo " print_r wp_cache_get: ";
 print_r($_page); ?>
 <?php echo " wp_cache_flush</strong"; wp_cache_flush(); ?>
 <?php echo " Post ID: " . $post->ID; ?>
 <?php echo ' $post->ancestors: ';
 print_r($post->ancestors); ?>
 <?php $page = get_page( $post->ID ); ?>
 <?php echo " print_r get_page: "; print_r($page);
 ?>
 <?php $_page = wp_cache_get($post->ID, 'posts'); ?>
 <?php echo " print_r wp_cache_get: ";
 print_r($_page); ?>
 }}}