Roles with empty password (probably bug in libpq and in psql as well).

Hey all,

According to http://www.postgresql.org/docs/9.2/static/sql-alterrole.html

A query:
ALTER ROLE davide WITH PASSWORD NULL;
removes a role's password.

But it's impossible to pass empty (NULL) password to the backend
by using libpq, because connectOptions2() defined the fe-connect.c
reads a password from the ~/.pgpass even when a password
specified as an empty string literal ("").

Also, when connecting to the server via psql(1) by using a role
with removed password psql exists with status 2 and prints the error
message:
psql: fe_sendauth: no password supplied

Thanks.

--
// Dmitriy.