bug#20319: nnoo.el not properly restoring back end server state

[Lars Ingebrigtsen <larsi@gnus.org>]

Alain Schneble <a.s@realize.ch> writes:

> Hi,
>
> nnoo.el does not properly restore back end server state from
> nnoo-state-alist after closing one server (say server A) and reopening
> another (say server B), given that both servers use the same back end
> (server method). Cached state of server B won't be restored at all in
> this case.
>
> Steps to reproduce:
>
> 1. M-x gnus-other-frame
> 2. M-x gnus-group-enter-server-mode
> 3. For each server: M-x gnus-server-close-server
> 4. Repeat twice, once with [server] = A and once with [server] = B:
>    a) M-x gnus-server-add-server
>    b) nntp
>    c) [server]
>    d) M-x gnus-server-edit-server
>    e) Adapt shown elisp form to:
>       (nntp "[server]" (nntp-address "news.gnus.org"))
>    f) C-c C-c
> 5. On server A: M-x gnus-server-open-server
> 6. On server B: M-x gnus-server-open-server
> 7. On server A: M-x gnus-server-close-server

[...]

> Also, I do not understand why nil server's data is stored (re-pushed)
> onto the nnoo-state-alist by nnoo-push-server at all.  My understanding
> is that nil server's data shall be immutable once it's been initialized.

I've done some tracing here, and I think that possibly the problem here
is that nn*-close-server is called with incomplete data: It's only
called with the server name, and not with the actual address.

I've now changed this in the interface function in Emacs 27, and things
look more regular now, but the recipe here to reproduce was a bit
... long, so I'm not 100% sure.

Would it be possible to upgrade and check?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no