bug#64062: Emacs 29.0.91: With enable-recursive-minibuffers, C-x b foo splits the window.

bug#64062: Emacs 29.0.91: With enable-recursive-minibuffers, C-x b foo splits the window.

[Alan Mackenzie]

In emacs-29.0.91:

emacs -Q
M-: (setq enable-recursive-minibuffers t)
M-x
C-x b foo

This creates the buffer foo, but erroneously splits the displayed window
and displays the new buffer in the right hand or bottom half of the
frame (depending on the frame's geometry).

The window should not be split, and the new buffer should occupy the
entirety of the original window.

-- 
Alan Mackenzie (Nuremberg, Germany).

bug#64062: Emacs 29.0.91: With enable-recursive-minibuffers, C-x b foo splits the window.

[Alan Mackenzie]

On Wed, Jun 14, 2023 at 10:35:07 +0000, Alan Mackenzie wrote:
> In emacs-29.0.91:

> emacs -Q
> M-: (setq enable-recursive-minibuffers t)
> M-x
> C-x b foo

Apologies: that last line should have read:

  C-x b foo RET.

> This creates the buffer foo, but erroneously splits the displayed window
> and displays the new buffer in the right hand or bottom half of the
> frame (depending on the frame's geometry).

> The window should not be split, and the new buffer should occupy the
> entirety of the original window.

> -- 
> Alan Mackenzie (Nuremberg, Germany).

bug#64062: Emacs 29.0.91: With enable-recursive-minibuffers, C-x b foo splits the window.

[Gregory Heytings]

>
> emacs -Q
> M-: (setq enable-recursive-minibuffers t)
> M-x
> C-x b foo
>
> This creates the buffer foo, but erroneously splits the displayed window 
> and displays the new buffer in the right hand or bottom half of the 
> frame (depending on the frame's geometry).
>
> The window should not be split, and the new buffer should occupy the 
> entirety of the original window.
>

AFAICS, that's not a bug.  Emacs 25, 26, 27 and 28 behave the same 
(switch-to-buffer calls pop-to-buffer), and it makes sense to leave, by 
default, the buffer in which M-x was called visible.  You can customize 
that behavior with display-buffer-base-action.

bug#64062: Emacs 29.0.91: With enable-recursive-minibuffers, C-x b foo splits the window.

[Eli Zaretskii]

> Cc: 64062@debbugs.gnu.org
> Date: Wed, 14 Jun 2023 10:58:39 +0000
> From: Gregory Heytings <gregory@heytings.org>
> 
> > emacs -Q
> > M-: (setq enable-recursive-minibuffers t)
> > M-x
> > C-x b foo
> >
> > This creates the buffer foo, but erroneously splits the displayed window 
> > and displays the new buffer in the right hand or bottom half of the 
> > frame (depending on the frame's geometry).
> >
> > The window should not be split, and the new buffer should occupy the 
> > entirety of the original window.
> 
> AFAICS, that's not a bug.  Emacs 25, 26, 27 and 28 behave the same 
> (switch-to-buffer calls pop-to-buffer), and it makes sense to leave, by 
> default, the buffer in which M-x was called visible.  You can customize 
> that behavior with display-buffer-base-action.

Indeed, I don't think this long-time behavior is a bug.  It's more
like a feature.