BUG #2402: case insensitive match for unicode doesn't work

The following bug has been logged online:

Bug reference:      2402
Logged by:          Balázs Klein
Email address:      balazs.klein@t-online.hu
PostgreSQL version: 8.1
Operating system:   Gentoo Linux
Description:        case insensitive match for unicode doesn't work
Details:

case conversion and case insensitive match (with or without regular
expression) does not work with non standard (Greek, Turkish, Hungarian,
etc.) characters

Examples:

Select 'a' ILIKE 'A'
--True

Select 'á' ILIKE 'Á'
--False

Select 'a' ~* 'A'
--True

Select 'á' ~* 'Á'
--False

Select upper('a')='A'
--True

Select upper('á')='Á'
--False

You would get the same result with é,ó,ü,ű,ó or with many Greek
characters that I tried.

I raised this issue on pgsql.general -
http://groups.google.com/group/pgsql.general/browse_frm/thread/20aed89ab0e19
e3d/4771fb1be397afea#4771fb1be397afea
but there didn't seem to be an easy workaround for this

On a sidenote SQLServer2000 and Access also make mistakes with the
equivalent of upper/lower function but they give correct result with more
characters than PG. Which at least consistently fails:)

Regards.
Balázs