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

From: Gerd Möllmann <[email-masked]>
Date: Sat, 09 Aug 2025 11:01:56 +0200

Pip Cet <[email-masked]> writes:

> insertions.
>
>> So far I can't see what is the cause. I would have guessed something in
>> or around primitive-undo, but that hasn't changed forever.
>>
>> Adding Stef.
>
> Well, compact_undo_list is a nop with HAVE_MPS:

Sorry, I forgot to mention an important detail: this happens in master
but not emacs-30. Oscar's report is also for master, IIRC.

Really puzzling.