bug#61667: 29.0.60; Failure to redisplay

[Dmitry Gutov]

On 16/04/2023 09:01, Eli Zaretskii wrote:
> > Date: Sun, 16 Apr 2023 03:48:56 +0300
> > From: Dmitry Gutov<dgutov@yandex.ru>
> > Cc: Gregory Heytings<gregory@heytings.org>, Eli Zaretskii<eliz@gnu.org>,
> >   Po Lu<luangruo@yahoo.com>
> >
> > - Do some search using 'C-x p g', wait to see the results buffer
> > displayed but it's not displayed for a while. I look at the title bar -
> > and it already says*xref*, but the frame is still not updated. If I
> > press something like 'C-n' or 'C-f' now, that triggers the necessary
> > refresh.
> >
> > - When the said Xref buffers is selected, I press 'q'. Likewise, the
> > frame might not get updated for a while, still showing the previous
> > window configuration until I issue the next command.
> >
> > These are of course random and don't happen every time. Often enough to
> > be annoying, though.
> Is this with or without double-buffering?  If it's with
> double-buffering, do the problems go away if you disable
> double-buffering?

Good question: the above failure scenario reproduces even without XDBE. 
The frequency is about the same as with XDBE.