OID problem 7.2

Hi all.

I had a lot of problems upgrading from 7.1 to 7.2 with fields of
type oid. I ended up hand editing the dump to change them all to
integer. In my case, they should have been integer anyway, but there
are legitimate uses for oid fields. Sorry if I can't be any more
explicit about the problem I havn't had time to delve deep. But
it didn't seem to like nulls in oid columns. It also may or may
not be related to having an index on those oid columns. I suggest
someone may want to make sure that an oid column in 7.2 that contains
some nulls and possibly has an index can be properly dumped and
restored, and preferably also check that it can be dumped from 7.1
and restored 7.2.