Re: Gnus sometimes reports new messages but not showing them on IMAP server

[Eric Abrahamsen <eric@ericabrahamsen.net>]

Arash Esbati <arash@gnu.org> writes:

> Dan Christensen <jdc@uwo.ca> writes:
>
>> Neither of those does the full resync that `M-g' does for IMAP groups.
>
> I can confirm this.
>
>> I don't know what is going on behind the scenes, but `M-g' is necessary
>> for me to see up-to-date information sometimes.
>
> I haven't tried to read/understand the code, but in the Group buffer,
> neither 'g' nor 'C-u g' does what 'M-g' does inside the Summary buffer
> of an IMAP group.  And I would have expected that 'C-u g' in Group
> buffer fits the bill:
>
> ,----[ C-h f gnus-group-get-new-news RET ]
> | gnus-group-get-new-news is an autoloaded interactive subr-native-elisp
> | in ‘gnus-group.el’.
> | 
> | (gnus-group-get-new-news &optional ARG ONE-LEVEL)
> | 
> | Get newly arrived articles.
> | If ARG is a number, it specifies which levels you are interested in
> | re-scanning.  If ARG is non-nil and not a number, this will force
> | "hard" re-reading of the active files from all servers.
> | If ONE-LEVEL is not nil, then re-scan only the specified level,
> | otherwise all levels below ARG will be scanned too.
> | 
> `----
>
> Hopefully Eric can shed some light on this.

This is a long-standing bug, probably the most annoying thing about
nnimap. I've made a few attempts at it over the years, but so far
haven't been successful. I believe what it comes down to is that "M-g"
dumps Gnus' "active" number and re-reads it from the IMAP server, while
regular "g" incrementally modifies the active number based on newest
changes. So if anything goes wrong with Gnus' active number, errors will
accumulate from that point until the user does "M-g".

I've focused on figuring out why the active number goes wrong, but in
the interest of pragmatism it might be better just to make sure that
nnimap always does the equivalent of "M-g" at Gnus startup.