BUG #4479: Incorrect TSearch2 results when inserting after deleting

The following bug has been logged online:

Bug reference:      4479
Logged by:          Dan Fabulich
Email address:      dan@fabulich.com
PostgreSQL version: 8.3.4
Operating system:   OS X 10.5.5
Description:        Incorrect TSearch2 results when inserting after deleting
Details:

Run the following psql script on Postgres 8.3.4.  I've reproduced this on
Centos 5.2 and RhodiumToad on IRC reproduced the problem as well.

EXPECTED: The last two SELECT statements should return the same results (1
row)
ACTUAL: The final SELECT statement returns 0 results.  The SELECT statement
just before it returns 1 result.

DROP DATABASE search_bug;
CREATE DATABASE search_bug;
\c search_bug

CREATE TABLE search_test (id bigserial PRIMARY KEY, name_search tsvector
default NULL, name_keywords varchar(255) default NULL);
CREATE INDEX name_search_index ON search_test USING gist(name_search);
create trigger name_search_update before update or insert on search_test for
each row execute procedure tsvector_update_trigger(name_search,
'pg_catalog.english', name_keywords);
SELECT * from search_test where name_search @@ to_tsquery('Noe');
-- should and does return nothing

INSERT INTO search_test (name_keywords) VALUES ('Noe Valley');

SELECT * from search_test where name_search @@ to_tsquery('Noe');
-- should and does return 1 row

DELETE from search_test where id = 1;

INSERT INTO search_test (name_keywords) VALUES ('Noe Valley');

SELECT * from search_test where name_search @@ to_tsquery('Noe');
-- should and does return 1 row

SELECT * from search_test where name_search @@ to_tsquery('Noe');
-- should return 1 row BUT RETURNS 0 ROWS; BUG!