Subject: Re: bug#79200: 31.0.50; Duplicated elements for '#<marker at' in buffer-undo-list

From: Alan Mackenzie <[email-masked]>
Date: Thu, 14 Aug 2025 10:26:57 +0000

Hello, Gerd.

On Thu, Aug 14, 2025 at 11:53:40 +0200, Gerd Möllmann wrote:
> Gerd Möllmann <[email-masked]> writes:

> > Alan Mackenzie <[email-masked]> writes:

> >> For what it's worth, I put next--marker-id into my Emacs, just as a
> >> counter, nothing else.

> >> In my emacs -Q, I do C-h v next--marker-id like you did, and a repeated
> >> g to refresh it.  I get just 76 markers made at each iteration.

> > Also interesting. With emacs -Q -nw, I get a delta of ca. 140, and in
> > the GUI (mac) I get 270.

> >> That makes your 472 look high indeed.  Might it possibly be there's a
> >> bug with DEFVAR_INT somewhere, and that 472 = 8 * 59 has wrongly got the
> >> 3 type bits in it, and is really just 59?  Just a suggestion.

> > I think that's unlikely. There are a lot such defvar, and I think
> > someone would have noticed such a bug.

> Another interesting detail that I didn't remember are the values of
> undo-limit and undo-strong-limit. I don't understand why they are so
> high (160000/240000). With 1 undo/s, I could undo for 2 days.

> Whatever, Maybe I'm overlooking something here. 

I think those limits are numbers of bytes, not numbers of undo
operations.  A single kill command in a big buffer could easily fill
these numbers of bytes.

I more wonder why those limits are so low.  It's a long time since PCs'
RAM capacity was measured in mere megabytes.

-- 
Alan Mackenzie (Nuremberg, Germany).