Re: [Nmh-workers] IMAP/nmh, again

[Paul Vixie]

Bakul Shah wrote:
> On Thu, 26 Oct 2017 17:26:37 -0400 address@hidden wrote:
> address@hidden writes:
> > AIUI, the big issue has always been that nmh has expected message numbers
> > to remain static until explicitly changed (i.e.  message 35 *stays* message 35
> > until 'folder -pack' or something changes it), while IMAP message numbers
> > can change even during a connection, so UUID's need to be used instead,
> > which means keeping a message<->uuid mapping someplace.
>
> Indeed.  Keeping such mapping is what I planned to do. folder
> -pack only changes the local msgID<->UID map so no need to
> talk to the server for that. But as UIDs are assigned by the
> imap server, after a refile there will be messages with no UID
> (at least temporarily).

fwiw, that sounds pretty reasonable.

> > And making that robust under concurrent access sounds even worse...
>
> Luckily this is taken care of by various imap extensions as
> the problem exists even for "pure" imap clients. But I have a
> feeling we will discover more corner cases + imap server
> implementations that don't quite do the right thing.

there's a think in imap called "push", which is part of why i keep 
saying that true imap support in mh would look like prayermail's session 
layer, although probably implemented as something like gpg-agent or 
ssh-agent. we're going to need a persistent connection, regardless of 
how fast or slow it is to set up and/or tear down those connections, be 
then LAN, WAN, SSL, TLS, or whatever.

if ssh can talk to ssh-agent over a unix domain socket, and gpg likewise 
to its gpg-agent, then the unix way of doing this is clear. it's 
possible that a simple persistent imap session, accessible via 
reconnections to the unix socket, is all we need. or, it's possible that 
something more like prayermail, where there's some session layer caching 
and a different non-imap protocol spoken between the agent and the 
various mh commands, would serve us better.

sadly, i can already think of non-imap-related reasons why mh needs an 
agent of this kind. i think i'm infected with non-unix thinking. ouch.

--
P Vixie