Reported by entrez, wielding something fragile (potion of acid
perhaps), and using F to smash it against iron bars called breaktest()
directly, then a second time indirectly through hero_breaks() via
hit_bars(). There is a random chance to resist breaking (99% for
artifacts, 1% for other items) so breaktest() might say that something
will break on the first call and that it will not break on the second
call, or vice versa. That could remove uwep from inventory then leave
it in limbo without destroying it, or destroy uwep without removing it
from inventory first triggering impossible "obfree: deleting worn obj".
37e63f6829