Re: mark_object crash in 22.1 and latest CVS (as of tonight)

[Kalman Reti]

On Nov 14, 2007 1:51 PM, Stefan Monnier <monnier@iro.umontreal.ca> wrote:
> > Anyone know what the elements of the undo_list mean?  Some are conses
> > with a marker in their CAR and a number in their CDR, some are just
> > conses of two numbers and some are conses of a string and a number.
>
> It's documented in the docstring of buffer-undo-list.

Thanks for the pointer.

I've done some more experiments; it occurred to me that if the marker in the
undo list was gc-marked already when we got to the special processing, then
it would be skipped.  I verified this by splitting out the last of the
three-legged-and
conditions into its own if.  Presumably this means that the marker is
shared in some
other structure which got marked previously.  Could the last match data and the
undo list perhaps share a marker?  Where is the last match data kept?
If it isn't
there, any suggestions on how to go about finding out where another pointer to
this marker is stored?