do not free the "onstack" bitvector before checking its consistency.
do not free the "onstack" bitvector before checking its consistency.

this should fix Peter's problems on 64_bit Linux ---
could you pleas test it, Peter?

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb