Re: Edebug corrupting point in buffers.

[Alan Mackenzie]

Hello, Eli.

On Thu, Nov 03, 2022 at 15:29:57 +0200, Eli Zaretskii wrote:
> > Date: Thu, 3 Nov 2022 11:32:29 +0000
> > Cc: emacs-devel@gnu.org
> > From: Alan Mackenzie <acm@muc.de>

> > +@node Edebug Buffer Points
> > +@subsubsection Edebug's handling of buffer points
> > +
> > +When Edebug enters its recursive edit to get a command from the user,
> > +by default it saves the window points of each window in the selected
> > +frame (@pxref{Edebug Display Update}).  These are usually, but not
> > +always, the same as the values of point in the buffers displayed by
> > +these windows (@pxref{Window Point}).  On leaving the recursive edit,
> > +these window points get restored, but sometimes buffer points get
> > +overwritten by them too.
> > +
> > +This can occasionally be a problem when your program switches buffers
> > +and sets point in them.  The recommended workaround is to disable the
> > +option @code{edebug-save-windows}, for example with the command
> > +@kbd{W} (@pxref{Edebug Options}).
> > +
> >  @node Edebug Recursive Edit
> >  @subsubsection Edebug Recursive Edit

> > @@ -1657,6 +1674,11 @@ Edebug Options
> >  what happens to the window configurations, it is better to set this
> >  variable to @code{nil}.

> > +Saving the window configuration can sometimes corrupt the values of
> > +point in buffers displayed by these windows.  If this happens, you are
> > +recommended to set @code{edebug-save-windos} to @code{nil}.
> > +@xref{Edebug Buffer Points}.
> > +

> The node you added is very short, barely a dozen lines.  It makes
> little sense to have it separate from where edebug-save-windows is
> described.  So I think you should move it there.  The location of the
> node inside the manual's hierarchy is much less important than to have
> the information pertaining to edebug-save-windows in a single place,
> because no one reads the ELisp reference manual in its entirety.  The
> only thing we need to facilitate people finding this place is add good
> index entries there.

So you're proposing leaving the "The outside context" node incomplete,
according to its clearly defined purpose, and therefore wrong?  Why?

Remember, this patch is not about edebug-save-windows.  It's about point
getting corrupted.

> Thanks.

-- 
Alan Mackenzie (Nuremberg, Germany).