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

[Oleg I. Vdovikin]

----- 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
migrationfriendly


> 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.
>
    Right.

> 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
message.

>
> 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.

Regards,
    Oleg.