duplicate oids in pg_proc

There are some duplicate oids in pg_proc of May30 snapshot.

test=> select p1.oid,p1.proname,p2.proname from pg_proc p1,pg_proc p2
where p1.oid = p2.oid and p1.proname > p2.proname;

 oid|proname     |proname
----+------------+-----------
1377|textoctetlen|char
1374|octet_length|char_bpchar
1375|octet_length|bpchar
1376|octet_length|bpchar_char
1600|version     |line
(5 rows)

I know octet_length's are from my patch but for others I don't know.
Comments?
--
Tatsuo Ishii
t-ishii@sra.co.jp