On 2022-07-07,, at 16:10 , Eli Zaretskii <eliz@gnu.org> wrote:

Yes, this should test window_end_valid before using window_end_pos.
An alternative could be window-start point plus some estimation of the
window's text, perhaps?

Actually, we could be more accurate: we could use move_it_to,
similarly to what pos_visible_p does when passed -1 as the position.