bug#46908: 28.0.50; Dozens of spurious markers in buffer-undo-list

[Michael Heerdegen]

Michael Heerdegen <michael_heerdegen@web.de> writes:

> > But how comes that `add-to-history' affects `buffer-undo-list'?
>
> `add-to-history' has no relevance here, no.  There mere existence of a
> marker in any buffer does, IIUC, cause it to be referenced by
> buffer-undo-list sooner or later, because undoing and redoing inside
> text containing a marker is not always without ambiguity regarding
> marker positioning, so the undo system adds hints to buffer-undo-list
> how these markers must be placed/repositioned.

I did some more experimentation (repeated copy, paste, undo and
garbage-collect in *scratch*), and I saw that the number of markers
living in buffer-undo-list is not monotonously increasing.  After some
time, the amount settles between 20 and 45 or so.  And stays in that
range.  Giving that a large, but still limited number of copies of the
mark marker is stored in the mark rings, that amount of markers isn't a
surprise, and if the number is not constantly growing,
everything...works as expected so far I think.  Correct?

Michael.