[Dovecot] Re: Small change to make dovecot pop3 uw-imap migrationfriendly

Oleg I. Vdovikin oleg at cs.msu.su
Fri May 28 14:55:03 EEST 2004

----- Original Message ----- 
From: "Matthias Andree" <matthias.andree at gmx.de>
To: <dovecot at dovecot.org>
Sent: Friday, May 28, 2004 11:43 AM
Subject: [Dovecot] Re: Small change to make dovecot pop3 uw-imap

> Timo Sirainen <tss at iki.fi> writes:
> > On 27.5.2004, at 16:29, Oleg I. Vdovikin wrote:
> >
> >>     So, the only thing I've discovered is what POP3 uidls are
> >> different than ones used in the uw-imap. Luckily, the difference are
> >> only in the format string used in uidl response. So, I've made the
> >> following change in the code
> >
> > Actually I just wrote a similiar patch a few days ago .. :)
> > http://dovecot.org/patches/pop3-uidl-uwimap.patch it's against .10.5
> > which changed a bit.
> [...]
> > I was thinking about making this fully configurable, ie. a config option
> > which would accept printf-like string. "%v.%u" "%08xv%08xu" or
> > something. Or maybe it's not worth it, I'd have to look at other POP3
> > servers to see what different kinds of UIDs they use..
> Question: will this apply to all UIDs or just to those for new mail? I
> can't tell from the code fragment.
    In may particular environment this applied to all messages. Taking in
account that old messages was served by uw-pop3 they will not refeteched by
POP3 clients after the upgrade to dovecot.

> There are two requirements:
> 1. major: a UID that any client may have seen _MUST NOT_ change.

> This means that a formatting string MUST ONLY have an impact on newly
> arriving mail.
    No, there is no need to store the exact formatting string with each

> 2. minor: those who migrate from UWImap would like to use UWImap UIDs
>    for existing mail.
> This could be achieved by a little program that runs once per mailbox
> after the initial switch.
    There is no need for this. The only thing is needed - is just an ability
to specify the format string in the config file and use this forever. So,
for existing dovecot configuration (default) it will be like

pop3uidl = "%u.%u"

while for uw-imap migrated environment it should be changed to

pop3uidl = "%08x%08x"

    And everyone will be happy. No UIDL value changes.

> And note that the client must not care about the UIDL format as long as
> it's legal, so anything beyond "importing" the UWIMAP UIDL is bogus.
    There is no dependency on the UIDL format, but the dependecy on the
content for the messages received with old pop3 daemon.


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