[fw-auth] Migrating app with Zend_Auth_Ldap to 1.10

I just switched one of our development sites from 1.9.2 to 1.10.0 to
begin testing, and the first issue I ran into was with Zend_Auth_Ldap
(trying to authenticate against Active Directory). In the past, the
adapter would simply try to bind with the username and credentials
being tested. If the bind was successful, the account existed.

It now seems I have to specify a username and password in the LDAP
configuration to successfully authenticate. Is this correct? If so,
why was this change necessary?

This is the second time I have had to spend time debugging LDAP
authentication due to a change in ZF. (The first was from 1.8 to 1.9
when, for some unexplained reason, I found that I had to change
accountCanonicalForm from 2 to 4.) What is more frustrating is that
there are no migration notes regarding Zend_Auth_Ldap for 1.9 or 1.10.

Andrew