Re: How about making `set-minibuffer-window' obsolete?

[Alan Mackenzie]

Hello, Eli.

On Tue, Mar 16, 2021 at 20:42:32 +0200, Eli Zaretskii wrote:
> > Date: Tue, 16 Mar 2021 18:16:35 +0000
> > From: Alan Mackenzie <acm@muc.de>

> > Does anybody have any objection to me making set-minibuffer-window
> > obsolete?

> > It's defined in src/minibuf.c, but not used by any C function, and it's
> > not used by any Lisp in Emacs itself - the nearest to a use is a
> > commented out occurrence in lisp/textmodes/ispell.el.

> > This function just sets the C variable minibuf_window.  This variable is
> > defined (by comment) to be the minibuffer window of the selected frame.
> > So setting it to a random mini-window will cause nasty problems.

> > Actually, I'd prefer just to remove the function entirely - but there's
> > always the chance it's being used by some external library.

> > So, any objections?

> I'd object to obsoleting a command just because it can be dangerous
> when used unwisely.

Every use of this command is unwise.  It cannot possibly do anything
useful.  It can only cause problems.

> Emacs always gives you enough rope to hang yourself, and trusts you
> that you won't.

Rope is generally useful stuff.  Changing the value of an internal C
variable in violation of its definition is never useful.

This command appears to have been useful in the distant past - it's last
use was commented out in 1998 in the following commit:

    commit f5136913a18bd7415c59dbf7bcaf3c316593c41d
    Author: Richard M. Stallman <rms@gnu.org>
    Date:   Thu Apr 30 06:43:48 1998 +0000

        Generalized region skipping added.
        Checks comments only in code.
        Added backward compatible support for customize.

Could I ask you, please, to reconsider?

-- 
Alan Mackenzie (Nuremberg, Germany).