extra columns in intermediate nodes not being removed by top level of executor

I'm using 8.1 from CVS head of about two days ago.

Extra columns seem to be on sum(plays.length), videos.path, videoid

create or replace view niceplays as SELECT count(*) AS plays,
summary("substring"(v.path, '[^/]+$'::text), 50) AS filename,
avg(p.length)::interval(0) AS avg, sum(p.length)::interval(0) AS sum,
(( SELECT now() - plays.playtimestamp
FROM plays
WHERE plays.videoid = v.videoid
ORDER BY plays.playid DESC
LIMIT 1))::interval(0) AS lastplay
FROM plays p
LEFT JOIN videos v USING (videoid)
WHERE p.length <> '00:00:00'::interval AND v.path ~~ '/home/allan/TransGaming_Drive/libp/%'::text
GROUP BY v.path, v.videoid
ORDER BY sum(p.length::interval(0)) DESC;

allan=# select * from niceplays;
plays | filename | avg | sum | lastplay
-------+----------+----------+----------+-----------------
13 | | 00:06:07 | 01:19:26 | 20 days 18:33:51
8 | | 00:07:18 | 00:58:23 | 17 days 23:49:38
8 | | 00:04:13 | 00:33:44 | 31 days 22:55:20
3 | | 00:10:56 | 00:32:47 | 17 days 00:04:18
7 | | 00:04:34 | 00:32:00 | 31 days 22:55:36
6 | | 00:05:04 | 00:30:22 | 17 days 23:46:32
[...]
(868 rows)

allan=# select * from niceplays order by sum desc limit 3;
plays | filename | avg | sum | lastplay | | |
-------+----------+----------+----------+------------------+----------+-+-----
13 | | 00:06:07 | 01:19:26 | 20 days 18:35:59 | 01:19:26 | | 43
8 | | 00:07:18 | 00:58:23 | 17 days 23:51:47 | 00:58:23 | | 1988
8 | | 00:04:13 | 00:33:44 | 31 days 22:57:29 | 00:33:43 | | 1961

Allan Wang