added None to support zope __provides__, [ticket:882]

diff --git a/lib/sqlalchemy/orm/attributes.py b/lib/sqlalchemy/orm/attributes.py
index bb713b30ab794b2cd222f22054a218c8388174c6..9cfee5222a7d4805923d20dea5a92ddfb10120f2 100644 (file)
--- a/lib/sqlalchemy/orm/attributes.py
+++ b/lib/sqlalchemy/orm/attributes.py
@@ -961,7 +961,7 @@ def register_class(class_, extra_init=None, on_exception=None):
     # (like associationproxy) become aware of themselves at the 
     # class level
     for key in dir(class_):
-        getattr(class_, key)
+        getattr(class_, key, None)
     
     oldinit = None
     doinit = False