BUG #6452: psql: can't change client encoding from the command line

The following bug has been logged on the website:

Bug reference: 6452
Logged by: Félix
Email address: felix(dot)gerzaguet(at)gmail(dot)com
PostgreSQL version: 9.1.2
Operating system: Win XP Pro SP3
Description:

Hi,

here is the problem:

Using the command line, I can't change the client encoding, but I can change
it using the "\encoding" command :

C:\>psql --variable=ENCODING=UTF8
could not find a "psql" to execute
could not find a "psql" to execute
psql (9.1.2)
WARNING: Console code page (850) differs from Windows code page (1252)
8-bit characters might not work correctly. See psql reference
page "Notes for Windows users" for details.
Type "help" for help.

postgres=# \encoding
WIN1252
postgres=# \echo :ENCODING
WIN1252
postgres=# \encoding UTF8
postgres=# \encoding
UTF8
postgres=# \echo :ENCODING
UTF8
postgres=# \q