bug#51521: Emacs-28 and Master. Unwanted display artifacts in multiple column tty displays.

[Eli Zaretskii]

> Date: Sat, 30 Oct 2021 23:26:30 +0000
> Cc: Eli Zaretskii <eliz@gnu.org>
> From: Alan Mackenzie <acm@muc.de>
> 
> Hello, Emacs and Eli.
> 
> In the master and emacs 28 branches, on a Linux console or a maximised X
> Window, do this:
> 
> (i) emacs -Q -nw
> (ii) C-x 4 C-f <some file with plenty of blank lines> RET
> (iii) M-> ; to end of buffer
> (iv) Hold down <up> (or ? C-p).
> 
> As point passes the top of the window, this will cause the window to
> scroll.  Notice that the divider between the left and right windows
> loses glyphs - they gradually become replaced by spaces.  This is a bug.

Thanks, should be fixed now.