BUG #2535: Unicode on Windows: aogonek is not distinguished from agrave

The following bug has been logged online:

Bug reference: 2535
Logged by: Marius alinauskas
Email address: mariusz(at)splius(dot)lt
PostgreSQL version: 8.1.4
Operating system: Windows XP Pro
Description: Unicode on Windows: aogonek is not distinguished from
agrave
Details:

It seems that on Windows PostgreSQL v8.1.4 does not distinguish aogonek
(U+0104, U+0105) from agrave (U+00C0, U+00E0):

CREATE DATABASE tests ENCODING = 'UTF8';

\c tests

CREATE TABLE foo
(
bar char(1) PRIMARY KEY
);

-- OK
INSERT INTO foo (bar) VALUES ('');

-- ERROR: duplicate key violates unique constraint
INSERT INTO foo (bar) VALUES ('');

-- Same thing with capitals

-- OK
INSERT INTO foo (bar) VALUES ('');

-- ERROR: duplicate key violates unique constraint
INSERT INTO foo (bar) VALUES ('');