Possible temp table bug in PostgreSQL 7.4.7 / 8.0.1

Hello,

I've probably found a temp table bug in PostgreSQL (tested with 7.4.7 and
8.0.1 on Linux x86).

Here's a demonstration of the bug:

CREATE FUNCTION testfunction()
RETURNS void
AS '
BEGIN
CREATE TEMP TABLE testtable (field int4) ON COMMIT DROP;

INSERT INTO testtable (field) VALUES (1);

-- DROP TABLE testtable;

RETURN;
END;
' LANGUAGE 'plpgsql';

database=# SELECT testfunction();

testfunction
--------------

(1 row)

database=# SELECT testfunction();
ERROR: relation with OID 29308882 does not exist
CONTEXT: SQL statement "INSERT INTO testtable (field) VALUES (1)"
PL/pgSQL function "testfunction" line 4 at SQL statement

No transaction has been started manually.

If I drop the temporary testtable manually within the PL/pgSQL function,
everything runs fine. Bug or feature? ;-)

Cheers,
Oliver