bug#46019: 27.1.90; gnus-group-list improperly sorted, drops meaningful group

[Eric Abrahamsen <eric@ericabrahamsen.net>]

Juan José García Ripoll <juanjose.garciaripoll@gmail.com> writes:

> The problem:
>
> - On a running Gnus instance, the list of groups in gnus-group-list is
>   not properly sorted: dummy.group gets close to the end.
>
> Symptoms:
>
> - As a result, the first group in the list is never shown, except when
>   going to the server list
>
> Steps to reproduce:
>
> In my site, a simple configuration to poll an IMAP server shows the
> problem. This configuration is stored in launcher.el and ran with
> "emacs -Q -l launcher.el"
>
> (require 'gnus)
> ;; Passwords for my server
> (setq auth-sources '("~/OneDrive/Library/dot.authinfo.gpg"))
> (epg-find-configuration 'OpenPGP)
> ;; Save configuration elsewhere, not to clobber my system
> (setq gnus-directory "~/tmp/")
> (setq gnus-startup-file (expand-file-name ".newsrc" gnus-directory))
> (setq gnus-select-method '(nnnil ""))
> (setq gnus-secondary-select-methods
>       '((nnimap "work"
>                 (nnimap-address "work.imap.server.com")
>                 (nnimap-server-port 993)
>                 (nnimap-stream ssl)
>                 (nnimap-fetch-partial-articles t))))
> (gnus)
> (print gnus-group-list)
>
> What happens:
>
> - Emacs outputs a list of groups that begins with "nnimap+work:Trash",
>   with dummy.group close to the end
>
> ("nnimap+work:Trash" "nnimap+work:Archive" ... "dummy.group" "nndraft:drafts")
>
> - When pressing 'L' to get the list of groups, Trash is removed, due to
>   the code in gnus-group-prepare-flat
>
> (defun gnus-group-prepare-flat (level &optional predicate lowest regexp)
>  ...
>       ;; List living groups, according to order in `gnus-group-list'.
>       (dolist (g (cdr gnus-group-list))
>         (setq info (gnus-get-info g)
> 	      group (gnus-info-group info)
>
> What should happen:
>
> - The list of groups should remain sorted, with dummy.group at the
>   beginning

This looks like a fairly straightforward error on my part (obviously at
some point I thought the NEXT argument meant "insert after this"), but
just to make sure I've got the right end of the stick -- does this only
happen once, during group subscription? Or does the group stay missing
across Gnus restarts.

Probably the best thing to do would be just to get rid of the
requirement to have a dummy group at all...