bug#55312: 29.0.50; Cannot set vscroll when mini-window is resized

[Eli Zaretskii]

> From: Po Lu <luangruo@yahoo.com>
> Cc: 55312-done@debbugs.gnu.org
> Date: Mon, 09 May 2022 09:38:46 +0800
> 
> Po Lu <luangruo@yahoo.com> writes:
> 
> > Thanks.  I think I'd prefer the latter, and will begin working on it.
> 
> Now done, so I'm closing this bug report.

Hmm... shouldn't we reset the new flag not just when w->force_start is
non-zero?  Otherwise, the flag could survive more than a single
redisplay cycle, and affect situations that the caller of
set-window-vscroll didn't intend, no?

How about resetting the flag in mark_window_display_accurate_1 as
well?