Here is an updated patch for LdapAuthenticationManager.java. I believe I've addressed all you concerns and suggestions, which resulted in some minor re-factoring. I have also added more error checking and logging which I think will make it significantly easier to diagnose problems that might occur - particularly related to configuration settings. I believe I have tested just about every path.

Please review this, and let me know if any further changes are necessary, of if you need any more info. If it looks okay, we'd like to get it into the 12.1 release, if that's possible.

Thanks.

Andy