1 files changed, 20 insertions, 14 deletions
diff --git a/lib/sqlalchemy/orm/session.py b/lib/sqlalchemy/orm/session.py
index 9a0438fc9..9e504c104 100644
--- a/lib/sqlalchemy/orm/session.py
+++ b/lib/sqlalchemy/orm/session.py
@@ -4,7 +4,7 @@
 # This module is part of SQLAlchemy and is released under
 # the MIT License: http://www.opensource.org/licenses/mit-license.php
 
-from sqlalchemy import util, exceptions, sql
+from sqlalchemy import util, exceptions, sql, engine
 from sqlalchemy.orm import unitofwork, query
 from sqlalchemy.orm.mapper import object_mapper as _object_mapper
 from sqlalchemy.orm.mapper import class_mapper as _class_mapper
@@ -30,8 +30,6 @@ class SessionTransaction(object):
     def connection(self, mapper_or_class, entity_name=None):
         if isinstance(mapper_or_class, type):
             mapper_or_class = _class_mapper(mapper_or_class, entity_name=entity_name)
-        if self.parent is not None:
-            return self.parent.connection(mapper_or_class)
         engine = self.session.get_bind(mapper_or_class)
         return self.get_or_add(engine)
 
@@ -39,28 +37,36 @@ class SessionTransaction(object):
         return SessionTransaction(self.session, self)
 
     def add(self, bind):
+        if self.parent is not None:
+            return self.parent.add(bind)
+            
         if self.connections.has_key(bind.engine):
             raise exceptions.InvalidRequestError("Session already has a Connection associated for the given Connection's Engine")
         return self.get_or_add(bind)
 
     def get_or_add(self, bind):
-        # we reference the 'engine' attribute on the given object, which in the case of
-        # Connection, ProxyEngine, Engine, whatever, should return the original
-        # "Engine" object that is handling the connection.
-        if self.connections.has_key(bind.engine):
-            return self.connections[bind.engine][0]
-        e = bind.engine
-        c = bind.contextual_connect()
-        if not self.connections.has_key(e):
-            self.connections[e] = (c, c.begin(), c is not bind)
-        return self.connections[e][0]
+        if self.parent is not None:
+            return self.parent.get_or_add(bind)
+            
+        if self.connections.has_key(bind):
+            return self.connections[bind][0]
+
+        if not isinstance(bind, engine.Connection):
+            e = bind
+            c = bind.contextual_connect()
+        else:
+            e = bind.engine
+            c = bind
+
+        self.connections[bind] = self.connections[e] = (c, c.begin(), c is not bind)
+        return self.connections[bind][0]
 
     def commit(self):
         if self.parent is not None:
             return
         if self.autoflush:
             self.session.flush()
-        for t in self.connections.values():
+        for t in util.Set(self.connections.values()):
             t[1].commit()
         self.close()