[Plugin: WP Super Cache] found possible bug with starting new post

I believe I have tracked down a bug in wp-super-cache where starting a new post on occasion can cause a long delay on busy blogs, especially exaggerated if there the time between garbage collection is extra long so there are many files.

Basically every time a new post is started, WordPress does two things – forces a new post to be created in the database for drafts – but also then attempts to delete all existing auto-drafts more than 7 days old.

Note how the post status is set to AUTO-DRAFT, not just DRAFT This may be from a legacy change in wordpress where they added statuses and your plugin existed before then.

if ( $create_in_db ) {
               // Cleanup old auto-drafts more than 7 days old
               $old_posts = $wpdb->get_col( "SELECT ID FROM $wpdb->posts WHERE
post_status = 'auto-draft' AND DATE_SUB( NOW(), INTERVAL 7 DAY ) >
post_date" );
               foreach ( (array) $old_posts as $delete )
                       wp_delete_post( $delete, true ); // Force delete
               $post_id = wp_insert_post( array( 'post_title' => __( 'Auto Draft'
), 'post_type' => $post_type, 'post_status' => 'auto-draft' ) );
               $post = get_post( $post_id );
               if ( current_theme_supports( 'post-formats' ) && post_type_supports(
$post->post_type, 'post-formats' ) && get_option(
'default_post_format' ) )
                       set_post_format( $post, get_option( 'default_post_format' ) );
       }

But over in wp-super-cache while you cleverly remembered to check for drafts and skip garbage collection when their status changes, you do NOT check for “auto-draft”, only “draft” – so the conditional FAILS and then proceeds into garbage collection anyway.

function wp_cache_post_change( $post_id ) {
	global $file_prefix, $cache_path, $blog_id, $super_cache_enabled, $blog_cache_dir, $blogcacheid, $wp_cache_refresh_single_only;
	static $last_processed = -1;

	if ($post_id == $last_processed) return $post_id;
	$last_processed = $post_id;
	$post = get_post( $post_id );
	if( $post->post_status == 'draft' ) {
		if ( isset( $GLOBALS[ 'wp_super_cache_debug' ] ) && $GLOBALS[ 'wp_super_cache_debug' ] ) wp_cache_debug( "wp_cache_post_change: draft post, not deleting any cache files.", 4 );
		return $post_id;
	}

My theory is untested as I have to leave for the evening but this sticks out like a sore thumb to me and I am wondering if you agree with this discovery since you know your code far better than I could after just a quick scan.

Maybe it should be changed from
if( $post->post_status == 'draft' ) {
to
if( $post->post_status != 'publish' ) {

considering how there could be dozens of post-status created in the future. I don’t even see “auto-draft” in the codex, only “draft” but it’s obviously in the 3.2 source.

Still not sure why a full prune is attempted when that option is definitely turned off but I have not traced through all the code yet.