bug#23483: 24.5; cygwin emacs w32 doesn not ask to save files when windows shuts down

[Eli Zaretskii]

> Cc: "23483@debbugs.gnu.org" <23483@debbugs.gnu.org>
> From: Ken Brown <kbrown@cornell.edu>
> Date: Fri, 13 May 2016 19:12:14 -0400
> 
> > Perhaps better is to have emacs simply abort a restart / shutdown and 
> > require the user to manually close emacs.  If it doesn't behave like other 
> > windows programs (query user to save unsaved files), then we have to 
> > remember emacs is special.  You could have a parameter for whether emacs 
> > aborts a windows shutdown, default to yes, and then users and consciously 
> > shut it off if they want.
> 
> I'm not convinced that this is better.  But as an experiment, I decided 
> to see if I could make emacs do what you want by having a system 
> shutdown trigger 'save-buffers-kill-emacs' instead of 'kill-emacs'. 
> What happened was that Windows complained that emacs was preventing it 
> from shutting down, and it gave me the choice of shutting down anyway or 
> canceling the shutdown.  I chose the latter, at which point I was faced 
> with a non-responsive emacs that had to be killed.
> 
> I don't have any further ideas.

AFAIK, doing what David wants is tricky technically (because our
message pump runs in a separate thread, which cannot run Lisp), and is
IMO not important enough for us to try getting out of our way.  Like I
said, having to answer all those questions always annoys me.

Thanks.