diff -r 3766853656d7 -r e330ead0804b web/views/authentication.py
--- a/web/views/authentication.py	Mon Oct 04 18:56:10 2010 +0200
+++ b/web/views/authentication.py	Mon Oct 04 18:59:32 2010 +0200
@@ -63,7 +63,7 @@
         """returns a login string or None, for repository session
         validation purposes
         """
-        return None
+        raise NotImplementedError()
 
 class LoginPasswordRetreiver(WebAuthInfoRetreiver):
     __regid__ = 'loginpwdauth'