The ldap bind is ok on the auth config page in ACP, but login fails without an error message.

Here is the fix:
diff includes/auth/auth_ldap.php includes/auth/auth_ldap.php.orig
155c155
< if (!@ldap_bind($ldap, htmlspecialchars_decode($config['ldap_user']), htmlspecialchars_decode($config['ldap_password'])))
—
> if (!@ldap_bind($ldap, $config['ldap_user'], htmlspecialchars_decode($config['ldap_password'])))

Following DRY this line of code should be moved in a function.