bug#21747: 25.0.50; while-no-input breaks kbd event handling when called from post-command-hook

[Eli Zaretskii <eliz@gnu.org>]

> Date: Mon, 26 Oct 2015 00:27:22 +0000
> From: Artur Malabarba <bruce.connor.am@gmail.com>
> Cc: 21747@debbugs.gnu.org
> 
> 2015-10-25 18:50 GMT+00:00 Eli Zaretskii <eliz@gnu.org>:
> >> Date: Sun, 25 Oct 2015 14:43:06 +0000
> >> From: Artur Malabarba <bruce.connor.am@gmail.com>
> >> Cc: Tassilo Horn <tsdh@gnu.org>, Stefan Monnier <monnier@iro.umontreal.ca>, Kim Storm <storm@cua.dk>,
> >>       21747@debbugs.gnu.org
> >>
> >> +otherwise the error might happen repeatedly and make Emacs nonfunctional.
> >> +
> >> +It is usually a bad idea to use this hook for expensive processing.
> >> +If unavoidable, `while-no-input' can be used avoid making Emacs
> >                                               ^^^
> > "to" is missing where indicated.
> >
> >> +unresponsive while the user types.  Furthermore, this hook is run
> >> +before redisplay, so the effect of the executed command won't be
> >> +displayed on the buffer until after the hook has finished (giving the
> >> +impression that Emacs is hanging).  You can call `redisplay' inside
> >> +`while-no-input' to avoid this.
> >
> > Perhaps only the 1st sentence or 2 sentences should be left in the doc
> > string, and the rest moved to the ELisp manual?  It seems too long and
> > detailed for a doc string.
> 
> How about reducing the second paragraph to this? Still to long?
> 
> It is a bad idea to use this hook for expensive processing.  If
> unavoidable, wrap your code in `(while-no-input (redisplay) CODE)' to
> avoid making Emacs unresponsive while the user types.

No, this is exactly right, thanks.