[wp-trac] [WordPress Trac] #25358: Last-Modified header is ' GMT' for feeds on sites with no approved comments when using a static Posts page

[WordPress Trac]

#25358: Last-Modified header is ' GMT' for feeds on sites with no approved comments
when using a static Posts page
--------------------------+-----------------------------
 Reporter:  joeybvi       |      Owner:
     Type:  defect (bug)  |     Status:  new
 Priority:  normal        |  Milestone:  Awaiting Review
Component:  Feeds         |    Version:  trunk
 Severity:  normal        |   Keywords:
--------------------------+-----------------------------
 The code in WP::send_headers() (source:/trunk/src/wp-includes/class-
 wp.php#L339), seen below, sets the Last-Modified header for feeds. The
 problem is that `get_lastcommentmodified('GMT')` will return null if the
 feed is a Static Posts page (there are no approved comments, and then the
 Last-Modified header will be set to ' GMT'. This breaks the Etag header as
 well, since that will be set to `md5(' GMT')`. And it also breaks the
 sending of a 304 status. For an example, see the headers for
 http://keyboardheadbashing.com/blog/feed/

 This also happens for a blog post's feed that has no current comments; see
 the headers for http://keyboardheadbashing.com/uncategorized/coming-
 soon/feed/

 My coworker also just pointed out that if there is an older comment (say,
 a comment from 11/11/2011) but there are newer posts (say, a post from
 12/12/2012), the date for the older comment will be used on both the
 Statics Posts page feed AND the specific-post feed (even if the post the
 feed is for is '''newer''' than the comment!).

 {{{
                         // We're showing a feed, so WP is indeed the only
 thing that last changed
                         if ( !empty($this->query_vars['withcomments'])
                                 || (
 empty($this->query_vars['withoutcomments'])
                                         && (
 !empty($this->query_vars['p'])
                                                 ||
 !empty($this->query_vars['name'])
                                                 ||
 !empty($this->query_vars['page_id'])
                                                 ||
 !empty($this->query_vars['pagename'])
                                                 ||
 !empty($this->query_vars['attachment'])
                                                 ||
 !empty($this->query_vars['attachment_id'])
                                         )
                                 )
                         )
                                 $wp_last_modified = mysql2date('D, d M Y
 H:i:s', get_lastcommentmodified('GMT'), 0).' GMT';
                         else
                                 $wp_last_modified = mysql2date('D, d M Y
 H:i:s', get_lastpostmodified('GMT'), 0).' GMT';
                         $wp_etag = '"' . md5($wp_last_modified) . '"';
                         $headers['Last-Modified'] = $wp_last_modified;
                         $headers['ETag'] = $wp_etag;
 }}}

 The code below will use the comment timestamp if it is set AND is newer
 than the post's timestamp; otherwise, it will use the post's timestamp:
 {{{
                         // We're showing a feed, so WP is indeed the only
 thing that last changed
                         if ( !empty($this->query_vars['withcomments'])
                                 || (
 empty($this->query_vars['withoutcomments'])
                                         && (
 !empty($this->query_vars['p'])
                                                 ||
 !empty($this->query_vars['name'])
                                                 ||
 !empty($this->query_vars['page_id'])
                                                 ||
 !empty($this->query_vars['pagename'])
                                                 ||
 !empty($this->query_vars['attachment'])
                                                 ||
 !empty($this->query_vars['attachment_id'])
                                         )
                                 )
                         )
                                 $comment_last_modified =
 strtotime(get_lastcommentmodified('GMT'));
                         $post_last_modified =
 strtotime(get_lastpostmodified('GMT'));
                         $wp_last_modified = date('D, d M Y H:i:s',
 isset($comment_last_modified) && $comment_last_modified >
 $post_last_modified ? $comment_last_modified : $post_last_modified).'
 GMT';
                         $wp_etag = '"' . md5($wp_last_modified) . '"';
                         $headers['Last-Modified'] = $wp_last_modified;
                         $headers['ETag'] = $wp_etag;
 }}}

 I will attach a patch for this change.

--
Ticket URL: <http://core.trac.wordpress.org/ticket/25358>
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