bug#26932: Found the triggering behaviour

[Lars Ingebrigtsen <larsi@gnus.org>]

Vivek Dasmohapatra <vivek@etla.org> writes:

> The old code in lui.el used to (effectively) do this:
>
>   (setq buffer-undo-list (mapcar a-lambda-here buffer-undo-list))
>
> This seemed to cause some strings in the undo list structure to get
> freed to early, then freed again later.
>
> The altered code uses the approach of setf'ing the relevant elements of
> the undo-list, which doesn't trick the GC code into a premature free.
>
> Since there's a workaround it's not particularly urgent, but it seems
> to me that there's a hole in the GC logic somewhere.

If I understand correctly, the external lui package set buffer-undo-list
to something invalid, and this led Emacs to segfault when gc-ing?

Was there any further work done here, or a reproducible test case
written?

-- 
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   bloggy blog: http://lars.ingebrigtsen.no