bug#33784: 27.0.50; some case c-backward-token-2 takes cpu more and emacs hang

[Eli Zaretskii]

> Date: Tue, 18 Dec 2018 21:05:07 +0000
> Cc: linux.xhyang@gmail.com, 33784@debbugs.gnu.org
> From: Alan Mackenzie <acm@muc.de>
> 
> > The real problem is probably performance.  But that's a guess; someone
> > will have to do the forensics to find out which change did that, and
> > then try to find related bug reports and/or discussions.
> 
> Hah!  The change, not to fontify buffers with names beginning with
> spaces, was made by Simon Marshall on 1995-12-09.  The list archives only
> go back to 2000.  :-(

Maybe we should simply remove that limitation.  Most temporary buffers
are in Fundamental mode anyway, and a few that aren't should support
font-lock.  If they are rarely or never displayed, we should be fine.

> Maybe the documentation for with-temp-buffer should be amended to
> recommend Lisp programmers not to use it for buffers holding user text.

I believe this is a limitation that is unjustifiably harsh.