BUG #5333: psql returns 0 on error

The following bug has been logged online:

Bug reference: 5333
Logged by:
Email address: pekka(dot)jarvinen(at)gmail(dot)com
PostgreSQL version: 8.4
Operating system: Ubuntu Karmic Koala
Description: psql returns 0 on error
Details:

$ psql -U foo -h 127.0.0.1 -f doesntwork.sql db
Password for user foo:
ERROR: invalid byte sequence for encoding "UTF8": 0xe46976
HINT: This error can also happen if the byte sequence does not match the
encoding expected by the server, which is controlled by "client_encoding".

$ echo $?
0

return value should be something else than 0.

doesntwork.sql just have contain something that doesn't work.