[wp-trac] [WordPress Trac] #23405: blog-details cache can get stuck with bad value

[WordPress Trac]

#23405: blog-details cache can get stuck with bad value
--------------------------+------------------------------
 Reporter:  westi         |       Owner:
     Type:  defect (bug)  |      Status:  new
 Priority:  normal        |   Milestone:  Awaiting Review
Component:  Multisite     |     Version:  3.5.1
 Severity:  normal        |  Resolution:
 Keywords:  needs-patch   |
--------------------------+------------------------------
Description changed by westi:

Old description:

> If you call '''get_blog_details''' for a blog which doesn't exist yet in
> '''wp_blogs''' then we cache a negative lookup result as '''-1''':
>
> https://core.trac.wordpress.org/browser/trunk/wp-includes/ms-
> blogs.php?rev=23389#L217
> '''
>         if ( empty($details) ) {
>                 $details = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM
> $wpdb->blogs WHERE blog_id = %d /* get_blog_details */", $blog_id ) );
>                 if ( ! $details ) {
>                         // Set the full cache.
>                         wp_cache_set( $blog_id, -1, 'blog-details' );
>                         return false;
>                 }
>         }
> '''
>
> When you then later call '''refresh_blog_details''' to clear up the cache
> for the blog_id the cached '''-1''' is passed to '''clean_blog_cache'''
> which then tries to get a blog_id from the object that was returned and
> doesn't get the right one and the cached are not deleted.
>
> This means that the blog ends up broken :(

New description:

 If you call {{{get_blog_details}}} for a blog which doesn't exist yet in
 {{{wp_blogs}}} then we cache a negative lookup result as {{{-1}}}:

 https://core.trac.wordpress.org/browser/trunk/wp-includes/ms-
 blogs.php?rev=23389#L217
 {{{
         if ( empty($details) ) {
                 $details = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM
 $wpdb->blogs WHERE blog_id = %d /* get_blog_details */", $blog_id ) );
                 if ( ! $details ) {
                         // Set the full cache.
                         wp_cache_set( $blog_id, -1, 'blog-details' );
                         return false;
                 }
         }
 }}}

 When you then later call {{{refresh_blog_details}}} to clear up the cache
 for the blog_id the cached {{{-1}}} is passed to {{{clean_blog_cache}}}
 which then tries to get a blog_id from the object that was returned and
 doesn't get the right one and the cached are not deleted.

 This means that the blog ends up broken :(

--

-- 
Ticket URL: <http://core.trac.wordpress.org/ticket/23405#comment:1>
WordPress Trac <http://core.trac.wordpress.org/>
WordPress blogging software