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

[Eli Zaretskii]

> Date: Tue, 18 Dec 2018 18:55:05 +0000
> Cc: linux.xhyang@gmail.com, 33784@debbugs.gnu.org
> From: Alan Mackenzie <acm@muc.de>
> 
> The current strategy is silently to ignore (font-lock-mode) when the
> buffer name begins with a space.  It feels to me like an easy to
> implement, but suboptimal, workaround to a real problem, whatever that
> real problem might be.

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.