From 6d486fb2e77e338ac4d45ff5ed45561abb5c81b3 Mon Sep 17 00:00:00 2001
From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Thu, 17 Jan 2008 16:24:26 +0000
Subject: [PATCH] check for session is none, [ticket:940]

---
 CHANGES                       | 2 ++
 lib/sqlalchemy/orm/session.py | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/CHANGES b/CHANGES
index af2101e5da..246853b3d9 100644
--- a/CHANGES
+++ b/CHANGES
@@ -51,6 +51,8 @@ CHANGES
     
     - fixed a rather expensive call in Query that was slowing
       down polymorphic queries
+
+    - miscellaneous tickets:  [ticket:940]
         
 - general
     - warnings are now issued as type exceptions.SAWarning.
diff --git a/lib/sqlalchemy/orm/session.py b/lib/sqlalchemy/orm/session.py
index 0d58a52161..e2bc71b92e 100644
--- a/lib/sqlalchemy/orm/session.py
+++ b/lib/sqlalchemy/orm/session.py
@@ -1141,7 +1141,7 @@ def object_session(instance):
     hashkey = getattr(instance, '_sa_session_id', None)
     if hashkey is not None:
         sess = _sessions.get(hashkey)
-        if instance in sess:
+        if sess is not None and instance in sess:
             return sess
     return None
 
-- 
2.47.3