Mike Kupfer <mkupfer@alum.berkeley.edu> writes:

> Try
>
>   emacs -Q
>   M-x shell
>   $ ksh
>   C-x 2
>
> On my Debian desktop (running Buster), that's enough to provoke
> misbehavior, without even resizing.

I'm also using Debian/bullseye, and it doesn't misbehave for me: