- Fixed bug whereby Session.merge() would call the

load() event with one too few arguments.
[ticket:2053]

- Added logic which prevents the generation of
events from a MapperExtension or SessionExtension
from generating do-nothing events for all the methods
not overridden. [ticket:2052]

5 files changed, 33 insertions, 17 deletions

diff --git a/lib/sqlalchemy/orm/deprecated_interfaces.py b/lib/sqlalchemy/orm/deprecated_interfaces.py
index 8cdde2282..135664469 100644
--- a/lib/sqlalchemy/orm/deprecated_interfaces.py
+++ b/lib/sqlalchemy/orm/deprecated_interfaces.py
@@ -83,10 +83,7 @@ class MapperExtension(object):
             me_meth = getattr(MapperExtension, meth)
             ls_meth = getattr(listener, meth)
 
-            # TODO: comparing self.methods to cls.method, 
-            # this comparison is probably moot
-
-            if me_meth is not ls_meth:
+            if not util.methods_equivalent(me_meth, ls_meth):
                 if meth == 'reconstruct_instance':
                     def go(ls_meth):
                         def reconstruct(instance, ctx):
@@ -401,16 +398,23 @@ class SessionExtension(object):
 
     @classmethod
     def _adapt_listener(cls, self, listener):
-        event.listen(self, 'before_commit', listener.before_commit)
-        event.listen(self, 'after_commit', listener.after_commit)
-        event.listen(self, 'after_rollback', listener.after_rollback)
-        event.listen(self, 'before_flush', listener.before_flush)
-        event.listen(self, 'after_flush', listener.after_flush)
-        event.listen(self, 'after_flush_postexec', listener.after_flush_postexec)
-        event.listen(self, 'after_begin', listener.after_begin)
-        event.listen(self, 'after_attach', listener.after_attach)
-        event.listen(self, 'after_bulk_update', listener.after_bulk_update)
-        event.listen(self, 'after_bulk_delete', listener.after_bulk_delete)
+        for meth in [
+            'before_commit',
+            'after_commit',
+            'after_rollback',
+            'before_flush',
+            'after_flush',
+            'after_flush_postexec',
+            'after_begin',
+            'after_attach',
+            'after_bulk_update',
+            'after_bulk_delete',
+        ]:
+            me_meth = getattr(SessionExtension, meth)
+            ls_meth = getattr(listener, meth)
+
+            if not util.methods_equivalent(me_meth, ls_meth):
+                event.listen(self, meth, getattr(listener, meth))
 
     def before_commit(self, session):
         """Execute right before commit is called.
diff --git a/lib/sqlalchemy/orm/events.py b/lib/sqlalchemy/orm/events.py
index 1e53a0279..de2147d36 100644
--- a/lib/sqlalchemy/orm/events.py
+++ b/lib/sqlalchemy/orm/events.py
@@ -181,7 +181,9 @@ class InstanceEvents(event.Events):
          instead be the :class:`.InstanceState` state-management
          object associated with the instance.
         :param context: the :class:`.QueryContext` corresponding to the
-         current :class:`.Query` in progress.
+         current :class:`.Query` in progress.  This argument may be
+         ``None`` if the load does not correspond to a :class:`.Query`,
+         such as during :meth:`.Session.merge`.
 
         """
 
diff --git a/lib/sqlalchemy/orm/session.py b/lib/sqlalchemy/orm/session.py
index 53f29ffeb..74e8a766f 100644
--- a/lib/sqlalchemy/orm/session.py
+++ b/lib/sqlalchemy/orm/session.py
@@ -1318,7 +1318,7 @@ class Session(object):
             merged_state.commit_all(merged_dict, self.identity_map)
 
         if new_instance:
-            merged_state.manager.dispatch.load(merged_state)
+            merged_state.manager.dispatch.load(merged_state, None)
         return merged
 
     @classmethod
diff --git a/lib/sqlalchemy/util/__init__.py b/lib/sqlalchemy/util/__init__.py
index f4861e5f4..015cc43db 100644
--- a/lib/sqlalchemy/util/__init__.py
+++ b/lib/sqlalchemy/util/__init__.py
@@ -25,7 +25,7 @@ from langhelpers import iterate_attributes, class_hierarchy, \
     monkeypatch_proxied_specials, asbool, bool_or_str, coerce_kw_type,\
     duck_type_collection, assert_arg_type, symbol, dictlike_iteritems,\
     classproperty, set_creation_order, warn_exception, warn, NoneType,\
-    constructor_copy
+    constructor_copy, methods_equivalent
 
 from deprecations import warn_deprecated, warn_pending_deprecation, \
     deprecated, pending_deprecation
diff --git a/lib/sqlalchemy/util/langhelpers.py b/lib/sqlalchemy/util/langhelpers.py
index 4088e85cb..7a7713d1e 100644
--- a/lib/sqlalchemy/util/langhelpers.py
+++ b/lib/sqlalchemy/util/langhelpers.py
@@ -323,6 +323,16 @@ def monkeypatch_proxied_specials(into_cls, from_cls, skip=None, only=None,
             pass
         setattr(into_cls, method, env[method])
 
+
+def methods_equivalent(meth1, meth2):
+    """Return True if the two methods are the same implementation."""
+
+    # Py3k
+    #return getattr(meth1, '__func__', meth1) is getattr(meth2, '__func__', meth2)
+    # Py2K
+    return getattr(meth1, 'im_func', meth1) is getattr(meth2, 'im_func', meth2)
+    # end Py2K
+
 def as_interface(obj, cls=None, methods=None, required=None):
     """Ensure basic interface compliance for an instance or dict of callables.