Quick coding question with acl fixes

Hi,

Usually i'd ply away at this one until I figured it out, but we're
running out of time :)

If I have the nspForm variable (which is a Form_pg_namespace) struct
pointer, then how do I check if the nspacl field is default (ie.
"NULL"). This is so I can avoid running DatumGetAclP on it, which seems
to cause alloc error reports.

gdb seems to think it's "$3 = {126}", and that doesn't seem to be NULL
or Datum(0) or anything. Anyone know the answer?

Also, there is an implementation question?

When I run through the acl changing all references from the old owner to
the new owner, should I combine the resulting acls if possible? Because
if the new owner already has some acls on that item, they will end up
with two acls.

Chris