[amcd]

very good article. :claps:

why should we use the 'global_start' hook? it would be better if vbulletin provided us with a 'session_create_complete' hook.

I think it would be better to use empty() instead of isset() because in class_core.php:

$session = $db->query_first_slave("
                SELECT *
                FROM " . TABLE_PREFIX . "session
                WHERE sessionhash = '" . $db->escape_string($sessionhash) . "'
                    AND lastactivity > " . (TIMENOW - $registry->options['cookietimeout']) . "
                    AND idhash = '" . $this->registry->db->escape_string(SESSION_IDHASH) . "'
            "
.
.
$this->vars =& $session;

This only affects existing sessions, so it will not matter after some time. It will only make a difference immediately after plugin installation or edit, but that may be significant in some situations.