[9fans] upas/fs to imap: removed messages sometimes regenerate

[9fans] upas/fs to imap: removed messages sometimes regenerate

[Anthony Sorace]

I'm seeing some odd (wrong) behavior with Plan 9's upas/fs and was
wondering of others have seen it, before I start digging further. I
use upas/fs to talk to a local mailbox and two IMAP servers. The local
store and one of the IMAP servers work reliably correctly. On the
other IMAP server, upas/fs will *sometimes* get into a state where
when I remove a message, it'll re-insert itself into the tree with a
higher message number. For example, with the IMAP server dalet:

:; cd /mail/fs/dalet
:; ls
1
2
ctl
:; rm 1 2 ; ls
3
4
ctl

Messages 3&4 are the same as 1&2; nothing new's actually come in.
Other IMAP clients I've used behave properly with this server. I've
not yet identified the pattern which causes it, but it's not random.
Anyone else seen this or similar?

Re: [9fans] upas/fs to imap: removed messages sometimes regenerate

[erik quanstrom]

> I'm seeing some odd (wrong) behavior with Plan 9's upas/fs and was
> wondering of others have seen it, before I start digging further. I
> use upas/fs to talk to a local mailbox and two IMAP servers. The local
> store and one of the IMAP servers work reliably correctly. On the
> other IMAP server, upas/fs will *sometimes* get into a state where
> when I remove a message, it'll re-insert itself into the tree with a
> higher message number. For example, with the IMAP server dalet:
>
> :; cd /mail/fs/dalet
> :; ls
> 1
> 2
> ctl
> :; rm 1 2 ; ls
> 3
> 4
> ctl
>
> Messages 3&4 are the same as 1&2; nothing new's actually come in.
> Other IMAP clients I've used behave properly with this server. I've
> not yet identified the pattern which causes it, but it's not random.
> Anyone else seen this or similar?

i've seen this before.  the problem was the client and server had lost
uid sync.  if you know a situation that always produces the behavior
it would be interesting to telnet directly to the server and snoop on
the uids.
	1 login $user $password
	2 select inbox
	3 status inbox (messages uidvalidity)
	4 uid fetch 1:* uid
<delete messages the normal way.  upas/fs uses "uid store %uld +flags (\Deleted)"
and then "expunge">
	5 uid fetch 1:* uid
will list all the available messages.  if you list the uids, delete messages
in a way that causes a problem, then you can list the uids again and
see if upas/fs or the server is at fault.

- erik