rework to expire() to make it smarter. when you expire(), history is immediately removed as well as explicit from dirty/deleted lists. this also changes uow.rollback_object() to remove from those lists, which is strange that it didnt do that before. anyway the mapper, when selecting and creating instances, asks the uow if this already identity-mapped instance is expired, and if so refreshes it on the fly, saving the need for the re-_get() operation, if some other query happens to touch upon the expired object. unit test added to confirm this.

1 files changed, 6 insertions, 0 deletions

diff --git a/lib/sqlalchemy/attributes.py b/lib/sqlalchemy/attributes.py
index cd01faddd..a5661ac5a 100644
--- a/lib/sqlalchemy/attributes.py
+++ b/lib/sqlalchemy/attributes.py
@@ -398,7 +398,13 @@ class AttributeManager(object):
         except KeyError:
             pass
         obj.__dict__['_managed_trigger'] = callable
+
+    def untrigger_history(self, obj):
+        del obj.__dict__['_managed_trigger']
         
+    def has_trigger(self, obj):
+        return obj.__dict__.has_key('_managed_trigger')
+            
     def reset_history(self, obj, key):
         """removes the history object for the given attribute on the given object.
         When the attribute is next accessed, a new container will be created via the