BUG #5970: intersect and collation on types

The following bug has been logged online:

Bug reference:      5970
Logged by:          Rikard Pavelic
Email address:      rikard.pavelic@zg.htnet.hr
PostgreSQL version: 9.1.alpha5
Operating system:   Windows XP SP3
Description:        intersect and collation on types
Details:

create table test_collation (id int, name varchar);
insert into test_collation values (1, 'abc'), (2,'bcd');

--works
select * from test_collation tc
intersect
select * from test_collation tc;

--doesn't work
select tc from test_collation tc
intersect
select tc from test_collation tc;