BUG #6034: pg_upgrade fails when it should not.

The following bug has been logged online:

Bug reference:      6034
Logged by:          Tim Uckun
Email address:      timuckun@gmail.com
PostgreSQL version: 8.4
Operating system:   ubuntu linux
Description:        pg_upgrade fails when it should not.
Details:

pg_upgrade from 8.4 to 9.0 fails with the following error message.

old and new cluster lc_collate values do not match


on 8.4 show lc_collate outputs
------------
 en_NZ.utf8
(1 row)


on 9.0 it outputs
------------
 en_NZ.UTF8
(1 row)


So the difference seems to be in capitalization. Presumably they are the
same collation with "different" names so it strikes me as odd that
pg_upgrade would balk and refuse to upgrade the database.

pg_upgrade should be able to tell that these are the same collations and go
ahead with the upgrade.

It also should give some indication of how to overcome the problem.