[skydancer]

I can report that this hack still works in 3.5.0 with a few small changes.

I got rid of the last postings.php modification in the .txt which read

FIND:
-------------------
$DB_site->query("UPDATE " . TABLE_PREFIX . "thread SET open = $threadinfo[open] WHERE threadid = $threadid");
-------------------
REPLACE WITH:
-------------------
$DB_site->query("UPDATE " . TABLE_PREFIX . "thread SET open = $threadinfo[open], reason = '" . addslashes($_POST[reason]) . "' WHERE threadid = $threadid");

Instead, I did the following:

FIND:
$vbulletin->url = 'showthread.php?' . $vbulletin->session->vars['sessionurl'] . "t=$threadid";

BEFORE IT, ADD:
$db->query("UPDATE " . TABLE_PREFIX . "thread SET reason='".addslashes($_POST[reason])."' WHERE threadid = $threadid");

It also may be useful to store the name of the moderator who closed it. To do this, I added:

FIND
if($_POST['reason'] == 'null') $_POST['reason'] = null;

BELOW IT, ADD:
$_POST['reason'] = "(".$vbulletin->userinfo['username'].") " . $_POST['reason'];

Cheers!
sd