Re: BUG #5314: Error in nested composite types in plpgsql. - Mailing list pgsql-bugs

Robert Haas <robertmhaas@gmail.com> writes:
> 2010/2/10 Oleg Serov <serovov@gmail.com>:
>> Somebody will fix this bug or not?

> I'm not sure whether this is a bug.

Yeah, I think it is.  The problem is that exec_move_row is taking too
many shortcuts with nulls.  If the input record is short of fields it
is willing to pass this data to exec_assign_value:

                value = (Datum) 0;
                isnull = true;
                valtype = InvalidOid;

The invalid datatype value doesn't matter in the scalar case, but
if the target is a sub-row it fails the type_is_rowtype() sanity
check in exec_assign_value.

The cleanest fix would probably be to use the target variable's
datatype here instead of InvalidOid.  Alternatively, we could
change exec_assign_value to not apply the sanity check unless
the input is non-null.

            regards, tom lane