Subject: Re: bug#37784: Buffer messed up when scrolling undecorated frame

From: Eli Zaretskii <[email-masked]>
Date: Thu, 17 Oct 2019 10:31:48 +0300

> From: Carlos Pita <[email-masked]>
> Date: Wed, 16 Oct 2019 21:52:24 -0300
> 
> When I set:
> 
> (set-frame-parameter nil 'undecorated t)
> 
> and then change to another window and back to emacs, then scroll
> around the window, I often end up with a very messed up buffer and
> have to run redraw-display in order to sanitize its contents. See
> attached screenshot.

What happens if you trigger redisplay after that setting, but before
switching off from the Emacs frame?