bug#9419: 24.0.50; C-x k deletes the entire frame instead of switching to another buffer

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sat, 03 Sep 2011 20:44:09 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 9419@debbugs.gnu.org
> 
> So how about this plan:
> 
>   . Never delete a frame, except when it was created by
>     display-buffer, and never had more than one buffer in its buffer
>     list.
> 
>   . Do the same with windows created by display-buffer: if the user
>     switched buffers in that window, don't delete the window when the
>     excursion ends.
> 
>   . Introduce a window-auto-delete option, by default set the same as
>     frame-auto-delete, to control window deletion like
>     frame-auto-delete controls that of frames.  Alternatively,
>     deprecate frame-auto-delete and introduce a new
>     frame-and-window-auto-delete with the old one its alias.  Then
>     make this new option control both window and frame auto-deletion
>     alike.

On second though, if we are trying to fix the specific use case of
save-window-excursion, why not solve it on the level of
save-window-excursion?  That is, let save-window-excursion keep track
of the window/frame created by display-buffer, and then delete that
window/frame when the excursion ends.

If this will solve the original problem, we can leave the behavior of
kill-buffer etc. as it was in Emacs 23.

WDYT?