collation problem on 9.1-beta1

Hi,

I've been starting to work on a 'what's new in 9.1' like i did last
year, and am faced with what I feel is a bug, while building a demo case
for collation.

Here it is:

SELECT * from (values ('llegar'),('llorer'),('lugar')) as tmp
order by 1 collate "es_ES.utf8";
ERROR:  collations are not supported by type integer at character 74
STATEMENT:  SELECT * from (values ('llegar'),('llorer'),('lugar')) as
tmp
order by 1 collate "es_ES.utf8";
                                                             ^
marc=# SELECT * from (values ('llegar'),('llorer'),('lugar')) as tmp
order by column1 collate "es_ES.utf8";
 column1
---------
 llegar
 llorer
 lugar
(3 rows)

Of course, without the collate keyword, the «order by 1» works as usual.

Regards

Marc