bug#55193: 29.0.50; Double-buffering on MS-Windows freezes cursor in minibuffer

[Eli Zaretskii]

> From: Po Lu <luangruo@yahoo.com>
> Cc: 55193@debbugs.gnu.org
> Date: Sat, 30 Apr 2022 18:55:24 +0800
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > The new double-buffering feature on MS-Windows causes unpleasant side
> > effect when the user types something into the minibuffer, then presses
> > RET to submit and exit the minibuffer.  Without double-buffering, the
> > cursor moves to the beginning of the minibuffer, thus providing visual
> > feedback that whatever the user typed was submitted.  With
> > double-buffering turned on, the cursor "freezes" in its last position,
> > at the end of the minibuffer text, until the command finishes and
> > redisplay does its job.  Which could be a tangible amount of time,
> > during which Emacs looks "frozen".
> >
> > To reproduce:
> >
> >   emacs -Q
> >   M-x blink-cursor-mode RET
> >   C-x C-f src/xdisp.c RET
> >
> > Observe that the cursor is at the end of the file name until such time
> > as xdisp.c is displayed, which could be a second or two in a
> > non-optimized build of Emacs.
> >
> > Can this be avoided, please, i.e. can we update the display after the
> > cursor is moved?
> 
> Thanks, should be fixed now.

Indeed, thanks.