bug#60886: 29.0.60; split-root-window-below broken for split-window-keep-point

[Eli Zaretskii]

> Date: Sat, 21 Jan 2023 16:30:57 +0100
> Cc: juri@linkov.net, 60886@debbugs.gnu.org
> From: martin rudalics <rudalics@gmx.at>
> 
>  >> This fails when WINDOW-TO-SPLIT is internal.
>  >
>  > Which buffer will be shown in the new window in that case?
> 
> If WINDOW-TO-SPLIT is live, the buffer shown in the new window is the
> buffer shown in WINDOW-TO-SPLIT.
> 
> If WINDOW-TO-SPLIT is not live, the buffer shown in the new window is
> the buffer shown in the selected window of WINDOW-TO-SPLIT's frame.

Thanks.  Then I suggest

    Split WINDOW-TO-SPLIT into two windows, one above the other.
  WINDOW-TO-SPLIT defaults to the selected window if omitted or nil.
  The newly created window will be below WINDOW-TO-SPLIT and will show
  the same buffer as WINDOW-TO-SPLIT, if it is a live window, else the
  buffer shown in the WINDOW-TO-SPLIT's frame's selected window.