Merge "repair mapper sort" into main

2 files changed, 17 insertions, 10 deletions

diff --git a/lib/sqlalchemy/orm/session.py b/lib/sqlalchemy/orm/session.py
index aa642e65e..cf47ee729 100644
--- a/lib/sqlalchemy/orm/session.py
+++ b/lib/sqlalchemy/orm/session.py
@@ -3389,14 +3389,24 @@ class Session(_SessionClassMethods):
 
         """
 
-        def key(state):
-            return (state.mapper, state.key is not None)
-
         obj_states = (attributes.instance_state(obj) for obj in objects)
+
         if not preserve_order:
-            obj_states = sorted(obj_states, key=key)
+            # the purpose of this sort is just so that common mappers
+            # and persistence states are grouped together, so that groupby
+            # will return a single group for a particular type of mapper.
+            # it's not trying to be deterministic beyond that.
+            obj_states = sorted(
+                obj_states,
+                key=lambda state: (id(state.mapper), state.key is not None),
+            )
 
-        for (mapper, isupdate), states in itertools.groupby(obj_states, key):
+        def grouping_key(state):
+            return (state.mapper, state.key is not None)
+
+        for (mapper, isupdate), states in itertools.groupby(
+            obj_states, grouping_key
+        ):
             self._bulk_save_mappings(
                 mapper,
                 states,
diff --git a/lib/sqlalchemy/util/typing.py b/lib/sqlalchemy/util/typing.py
index e2d42db6e..5767d258b 100644
--- a/lib/sqlalchemy/util/typing.py
+++ b/lib/sqlalchemy/util/typing.py
@@ -6,6 +6,8 @@ from typing import Type
 from typing import TypeVar
 from typing import Union
 
+from typing_extensions import NotRequired  # noqa
+
 from . import compat
 
 _T = TypeVar("_T", bound=Any)
@@ -26,11 +28,6 @@ else:
     from typing_extensions import Concatenate  # noqa
     from typing_extensions import ParamSpec  # noqa
 
-if compat.py311:
-    from typing import NotRequired  # noqa
-else:
-    from typing_extensions import NotRequired  # noqa
-
 
 _T = TypeVar("_T")