BUG #2970: "FETCH ABSOLUTE -1" from a holdable cursor failed

The following bug has been logged online:

Bug reference: 2970
Logged by: William ZHANG
Email address: uniware@zedware.org
PostgreSQL version: 8.2.2
Operating system: i686-pc-linux-gnu
Description: "FETCH ABSOLUTE -1" from a holdable cursor failed
Details:

DROP TABLE foo;
CREATE TABLE foo(fno INT);
INSERT INTO foo VALUES(generate_series(1,5));

BEGIN TRANSACTION;
DECLARE x SCROLL CURSOR WITH HOLD FOR SELECT fno FROM foo;
-- fetch all the 5 rows.
-- after that, cursor position should be past last row.
FETCH 10 FROM x;
COMMIT WORK;
-- try to fetch the last row.
-- it failed.
FETCH ABSOLUTE -1 FROM x;
CLOSE x;