Subject: Re: bug#43017: 27.1; Screen display error
From: Alan Third <[email-masked]>
To: Yu Fang <[email-masked]>
Cc: [email-masked]
Date: Mon, 24 Aug 2020 21:51:46 +0200 (CEST)
List-Id: <debbugs-submit.debbugs.gnu.org>

On Mon, Aug 24, 2020 at 05:30:19PM +0800, Yu Fang wrote:
> While moving cursor in frame, part or whole frame will become
> blank. Emacs 26 have same bug, Emacs 25 is ok.

Unfortunately this is due to a change in macOS 10.14 which took us a
very long time to work out.

Emacs 28 has a fix, but for Emacs 27 I'm afraid you'll just have to
force the screen to redraw whenever it happens.
-- 
Alan Third