Merge branch 'master' into ticket_3100

1 files changed, 5 insertions, 5 deletions

diff --git a/lib/sqlalchemy/orm/session.py b/lib/sqlalchemy/orm/session.py
index 968868e84..e075b9c71 100644
--- a/lib/sqlalchemy/orm/session.py
+++ b/lib/sqlalchemy/orm/session.py
@@ -271,7 +271,7 @@ class SessionTransaction(object):
                 del s.key
 
         for s, (oldkey, newkey) in self._key_switches.items():
-            self.session.identity_map.discard(s)
+            self.session.identity_map.safe_discard(s)
             s.key = oldkey
             self.session.identity_map.replace(s)
 
@@ -1397,7 +1397,7 @@ class Session(_SessionClassMethods):
             self._new.pop(state)
             state._detach()
         elif self.identity_map.contains_state(state):
-            self.identity_map.discard(state)
+            self.identity_map.safe_discard(state)
             self._deleted.pop(state, None)
             state._detach()
         elif self.transaction:
@@ -1430,10 +1430,10 @@ class Session(_SessionClassMethods):
                 if state.key is None:
                     state.key = instance_key
                 elif state.key != instance_key:
-                    # primary key switch. use discard() in case another
+                    # primary key switch. use safe_discard() in case another
                     # state has already replaced this one in the identity
                     # map (see test/orm/test_naturalpks.py ReversePKsTest)
-                    self.identity_map.discard(state)
+                    self.identity_map.safe_discard(state)
                     if state in self.transaction._key_switches:
                         orig_key = self.transaction._key_switches[state][0]
                     else:
@@ -1467,7 +1467,7 @@ class Session(_SessionClassMethods):
             if self._enable_transaction_accounting and self.transaction:
                 self.transaction._deleted[state] = True
 
-            self.identity_map.discard(state)
+            self.identity_map.safe_discard(state)
             self._deleted.pop(state, None)
             state.deleted = True