Subject: bug#42406: Mouse-wheel scrolling can be flickering

From: martin rudalics <[email-masked]>
Date: Wed, 16 Dec 2020 09:46:59 +0100

> As long as you invoke scrolling commands (and that's what the scroll
 > bar eventually does in Emacs), you will always have the same problem:
 > scrolling commands cause Emacs redraw all the frames.

Because it has to update mode lines or are there any other reasons?

martin