bug#10195: 24.0.92; M-w may no longer provide visual feedback

[Eli Zaretskii]

> From: Chong Yidong <cyd@gnu.org>
> Cc: md5i@md5i.com,  10195@debbugs.gnu.org,  ejb@ql.org
> Date: Sun, 04 Dec 2011 23:59:15 +0800
> 
> I don't think sit-for should ignore selection requests.  If so, doing
> (sit-for 10) would cause Emacs to stop responding to selection requests
> from other applications for 10 seconds.  That doesn't sound right.

What happens if an application receives a selection request while it
is busy with some long calculation? won't the response be delayed in
that case as well?

> I think the right fix is for input-pending-p to call swallow_events(),
> as below.  Thoughts?

I'm no expert on this, but it looks OK.  It only swallows selection
requests, though; are these the only ones that can cause this kind of
problems?