Subject: bug#63187: 30.0.50; Tail of longer lines painted after end of nearby lines on macOS

From: Eli Zaretskii <[email-masked]>
Date: Sun, 30 Apr 2023 18:26:42 +0300

> From: Aaron Jensen <[email-masked]>
> Date: Sun, 30 Apr 2023 10:57:35 -0400
> Cc: [email-masked], [email-masked]
> 
> For what it's worth, disabling it has had no discernible impact on
> scroll performance on my machine (which is an M1)

scrolling_window is not about scrolling.  It's a redisplay
optimization that attempts to speed up redrawing a window by scrolling
on display the stuff already shown, when that is deemed less costly
than redrawing every screen line that has changed.