I've updated IdentityManager to reject empty usernames, however I'm still surprised that at least no exception was thrown for you. I tried this with the seamspace example and it threw an LDAP exception.
I will give this a try again with a new Seam Web Project using 2.1.0.GA and report back whether I get an LDAP exception or not.
I am also new to ldap authentication. I have same problem couple days ago. I fixed this by putting
in my ldap application-policy in login-config.xml.
The thing I don't understand is should we do the same thing in LdapIdentyStore. I have not used to it and I wonder if i can use it to pull information (like first name,email out of the ldap)