Forum Upgrade 3.6.x to 4.0.0pl2 isn't clean because of attachments table weren't updated
 

Hello 2 all,
I'm trying to upgrade a 3.6.x board to 4.0.0pl2 directly by following upgrade.php procedure.

Before this I've disabled all hacks/mods/products then uninstalled, then deleted its files from filesystem.
I've converted 3.6.x 's attachments from database to filesystem mode.

Then i've run twice mysql tables repairing and chmod -R attachments dir

Running upgrade script i was stuck at upgrade_400b1.php then i've commented out following code:

Code:
// ################################################## ###########################
// step 1
if ($vbulletin->GPC['step'] == 1)
{
$upgrade->drop_index(
sprintf($upgradecore_phrases['altering_x_table'], 'attachment', 1, 2),
'attachment',
'contenttypeid'
);

/*
$upgrade->add_index(
sprintf($upgradecore_phrases['altering_x_table'], 'attachment', 2, 2),
'attachment',
'contenttypeid',
array('contenttypeid', 'contentid', 'attachmentid')
);
*/

$upgrade->execute();
}
Finally i was missing that column, I've seen at a scratch 4.0.0 database freshly installed before, then I've created it, and state column also (was missing)

But table still mess. I don't want to get rid of attachments and copy fresh table from scratch database, because users have uploaded more than 450.

Installing 3.8.4 before 4.0.0. is mandatory? Could solve that problem? Is there some other solution?