BUG #1837: varchar/text operator "=" not unicode safe?

The following bug has been logged online:

Bug reference: 1837
Logged by: Jrg Haustein
Email address: joerg(dot)haustein(at)urz(dot)uni-hd(dot)de
PostgreSQL version: 8.0.3
Operating system: Linux (SuSE 9.1)
Description: varchar/text operator "=" not unicode safe?
Details:

I have a UNICODE database, trying to compare two unicode strings (Ethiopic
characters). Client encoding is also UNICODE:

testdb=> select ' '=' ';
?column?
----------
t
(1 row)

Clearly, it can be seen that they are not equal. The "LIKE" operator also
seems to think so:

testdb=> select ' ' LIKE ' ';
?column?
----------
f
(1 row)

What is the problem here?
The behavior is the same with SQL_ASCII databases and the SQL_ASCII client
encoding.