BUG #4877: LDAP auth allows empty password string

The following bug has been logged online:

Bug reference:      4877
Logged by:          Richard Tector
Email address:      richard@tector.org.uk
PostgreSQL version: 8.3.7
Operating system:   FreeBSD 7.2-RELEASE-p1
Description:        LDAP auth allows empty password string
Details:

In general the client libraries for PostgreSQL error if an empty password is
used. The JDBC drivers do not, and this has uncovered a problem with the
server's LDAP authentication code.

When authenticating against Active Directory using the method:
ldap "ldap://osiris.capl.local/dc=capl,dc=local;CAPL\"
Authentication is successful with both the correct password and an empty
password, so long as a valid user is supplied. Using a non-existent username
or an incorrect password correctly produces an error and the logon fails.