bug#25875: 26.0.50; Hang logging out of MS-Windows

[Richard Copley <rcopley@gmail.com>]

On 28 February 2017 at 03:35, Eli Zaretskii <eliz@gnu.org> wrote:
>> From: Richard Copley <rcopley@gmail.com>
>> Date: Mon, 27 Feb 2017 23:03:26 +0000
>> Cc: Eli Zaretskii <eliz@gnu.org>, 25875@debbugs.gnu.org
>>
>> Please imagine: I report back after a week (or two, or four) and tell
>> you that Emacs didn't prevent any Windows shutdowns. In that time
>> I might have attempted to shut down Windows a handful of times.
>>
>> Will you have learned anything, anything at all?
>
> How representative would the above sample be, relative to the
> frequency of the problem you see when shutting down Windows?  If you
> see such problems almost every shutdown, then yes, we'd be learning a
> lot.

In the nine months since Ken's change, I've noticed a problem with
Emacs twice.

Ken, Eli, are you going to be running Emacs with that patch installed?

I can't get my head around the idea. If we don't care whether or not
the action in question has finished when SendMessage returns,
then why are we using SendMessage? And if we do care, then
shouldn't I expect weird bugs caused by timing out when the system's
under load?