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

[martin rudalics]

Do you mean in code wrapped in `save-match-data' you delete some region
of text containing a marker of the saved match-data.  Thus
record_marker_adjustment puts an entry on `buffer-undo-list' referencing
that marker.  The unwindforms of `save-match-data' call `set-match-data'
with evaporate/reseat non-nil, which calls free_marker and subsequently
free_misc.  mark_object - operating from `buffer-undo-list' - detects
that the object is already free and aborts.

If I understand correctly, this means that either markers used for
saving match-data should not go to `buffer-undo-list' or the "evaporate"
option set by `save-match-data' is inherently broken.