Re: Allowing point to be outside the window?

[Eli Zaretskii]

> From: Po Lu <luangruo@yahoo.com>
> Cc: emacs-devel@gnu.org
> Date: Tue, 07 Dec 2021 10:18:37 +0800
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Again, what do you mean by "start is forced"?  Emacs sometimes forces
> > the window-start upon itself, you can clearly see that in the code.
> 
> Whenever w->force_start is true.

This is sometimes set for Emacs itself, regardless of the user
commands.  So all such uses should be audited.

> > And if point is outside of the window, recentering makes no sense
> > anyway, because there's nothing to recenter about, there's no point of
> > reference for it.
> 
> The window start is moved to a suitable location which will cause point
> to be displayed in the center of the screen.
> 
> If that isn't possible, the closest location to that is set as window
> start.

Yes.  I'm saying that if point is allowed to be outside of the window
during some redisplay cycle, we'd need a different criteria for when
and how to change w->start.