bug#26862: Quit Gnus prompts about unsent messages, but messages can't be saved as drafts

[Katsumi Yamaoka <yamaoka@jpl.org>]

On Wed, 10 May 2017 11:27:05 +0200, Stephen Berman wrote:
> However, when I restart Gnus, I see that that unsent message is in the
> Drafts group, i.e., Gnus in fact saved it.  So it's a UI bug but doesn't
> lose data.

Good point.  Yes, nndraft runs the auto-save on a modified draft
with a certain period.  Prompting a user for a modified draft is
a normal operation of `kill-buffer', not Gnus' intention.  So we
may kill those buffers safely and silently.

On Wed, 10 May 2017 18:42:33 +0900, Katsumi Yamaoka wrote:
> It seems hard to make `C-c C-d' work in such a case.  Instead,
> how about killing those modified message buffers unconditionally?

Thanks Eric for suggestions and verifying a revised patch.  I've
committed it in master:
<http://lists.gnu.org/archive/html/emacs-diffs/2017-05/msg00237.html>

Where `do-auto-save' makes sure that latest drafts are saved.
(set-buffer-modified-p nil) is necessary to kill modified buffers
silently.
(setq kill-buffer-hook nil) assumes that a user might set it for
a certain purpose (I do it ;-), that might issue a useless prompt.

Regards,