Bug in renaming view columns

Hi,

Are we supposed to be able to rename view columns or not? You can't if
you replace the view, but you can if you rename the column.

test=# create view test as select 1 as a;
CREATE VIEW
test=# \d test
View "public.test"
Column | Type | Modifiers
--------+---------+-----------
a | integer |
View definition:
SELECT 1 AS a;

test=# create or replace view test as select 1 as b;
ERROR: cannot change name of view column "a"
test=# alter table test rename a to b;
ALTER TABLE
test=# \d test
View "public.test"
Column | Type | Modifiers
--------+---------+-----------
b | integer |
View definition:
SELECT 1 AS b;

Chris