Re: Does Gnus read and sync the read with IMAP?

[Eric Abrahamsen]

Dan Christensen <jdc@uwo.ca> writes:

> On Oct 19, 2023, Björn Bidar <bjorn.bidar@thaodan.de> wrote:
>
>> How can I make Gnus to fetch the read status from Imap?
>
> In the *Group* buffer, you can make Gnus update the marks from the IMAP
> server using `M-g'.
>
> Here's a followup question:  how can I make Gnus update the marks for
> *all* IMAP groups.  I've tried various incantations.  `g' doesn't work,
> nor does `M-g' on a topic containing the IMAP groups.  In fact, I'd
> like Gnus to always refresh IMAP groups in the thorough way that `M-g'
> on the group does, since I'm accessing a local IMAP server.

I once asked Lars about this -- since the IMAP server should be the
source of truth for all information about the messages, why does Gnus
store its own marks data for IMAP groups at all? Why not just refresh
from the server at each startup? I think he said that for many large
groups that would end up being prohibitively slow. I guess that might be
true, I don't know. I do think that Gnus should be much, much more
willing to dump its marks store and refresh if anything at all seems to
be getting out of whack.

Maybe we could put in a customization option that would clear out Gnus'
nnimap group marks at shutdown, which would force a full refresh at the
next startup. That feels like a pretty major change, I'm not sure what
the knock-on consequences might be.

The other common problem (that Bob Newell ran into recently) is that
Gnus' article numbers are purely an internal convention, and don't have
any real correspondence to external reality, yet are relied upon pretty
heavily within Gnus to "make sense" as an indicator of sequence. When
they get out of whack you are SOL. I don't see a great solution to that.

Eric