Re: emacs master + org Wrong type argument: number-or-marker-p

[Eli Zaretskii]

> Date: Mon, 1 Aug 2022 20:05:44 +0000
> Cc: Mattias Engdegård <mattiase@acm.org>,
>  Eli Zaretskii <eliz@gnu.org>, philipk@posteo.net, silent2600@gmail.com,
>  emacs-devel@gnu.org
> From: Alan Mackenzie <acm@muc.de>
> 
> I see in
> 
>     commit 9d8a6c82838f2f24e76a67379b02956aa668d7cf
>     Author: Gregory Heytings <gregory@heytings.org>
>     Date:   Mon Aug 1 19:11:01 2022 +0000
> 
> the following text:
> 
>     +Note that, in rare circumstances, Emacs may decide to leave, for
>     +performance reasons, the accessible portion of the buffer unchanged
>     +after a call to @code{narrow-to-region}.
> 
> You cannot do this.  narrow-to-region and widen aren't nice-to-have
> optional extras, they are essential parts of program functionality.  If
> you stop them working properly, programs will break.  It is a bit like
> the Lisp machine randomly failing to perform some car operations.

This happens only in buffers with very long lines, where we want to
prevent Lisp programs called from low-level facilities, like
redisplay, to scan the entire buffer.  "Normal" invocations from Lisp
will not meet with this.

> Would it also be possible to add in some commentry motivating this
> unusual action?

I added some verbiage.