bug#61667: 29.0.60; Failure to redisplay

[Eli Zaretskii]

> Cc: luangruo@yahoo.com, 61667@debbugs.gnu.org, gregory@heytings.org
> Date: Fri, 24 Feb 2023 17:51:05 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> 
> So, now, when does the delay happen?  I previously thought it happens
> when the frame's title changes, but now you are saying it (and the
> commit you mentioned) is unrelated, right?  Then what _is_ related?
> Just the display-related activity in windows around Emacs?

Also, if you use Emacs 25 with %b in frame-title-format, do you see
the problem?  If you do, then double buffering is off the hook.