Make SomeModel._default_manager return a BaseManager[SomeModel] instead of BaseManager[Model]

django-stubs/core/servers/basehttp.pyi

@@ -20,7 +20,7 @@ class ServerHandler(simple_server.ServerHandler):
 
 class WSGIRequestHandler(simple_server.WSGIRequestHandler):
     close_connection: bool
-    connection: WSGIRequest  # type: ignore[assignment]
+    connection: WSGIRequest
     request: WSGIRequest
     rfile: BytesIO
     wfile: BytesIO

django-stubs/db/models/base.pyi

@@ -5,6 +5,7 @@ from django.core.exceptions import MultipleObjectsReturned as BaseMultipleObject
 from django.core.exceptions import ObjectDoesNotExist, ValidationError
 from django.db.models.manager import BaseManager
 from django.db.models.options import Options
+from django.utils.functional import classproperty
 
 _Self = TypeVar("_Self", bound="Model")
 
@@ -22,8 +23,12 @@ class Model(metaclass=ModelBase):
     class MultipleObjectsReturned(BaseMultipleObjectsReturned): ...
     class Meta: ...
     _meta: Options[Any]
-    _default_manager: BaseManager[Model]
-    _base_manager: BaseManager[Model]
+    @classproperty
+    @classmethod
+    def _default_manager(cls: Type[_Self]) -> BaseManager[_Self]: ...
+    @classproperty
+    @classmethod
+    def _base_manager(cls: Type[_Self]) -> BaseManager[_Self]: ...
     objects: BaseManager[Any]
     pk: Any = ...
     _state: ModelState

django-stubs/utils/functional.pyi

@@ -62,8 +62,11 @@ def partition(
     predicate: Callable, values: List[_PartitionMember]
 ) -> Tuple[List[_PartitionMember], List[_PartitionMember]]: ...
 
-class classproperty:
-    fget: Optional[Callable] = ...
-    def __init__(self, method: Optional[Callable] = ...) -> None: ...
-    def __get__(self, instance: Any, cls: Optional[type] = ...) -> Any: ...
-    def getter(self, method: Callable) -> classproperty: ...
+_Get = TypeVar("_Get")
+_Self = TypeVar("_Self")
+
+class classproperty(Generic[_Get]):
+    fget: Optional[Callable[[Type[_Self]], _Get]] = ...
+    def __init__(self, method: Optional[Callable[[Type[_Self]], _Get]] = ...) -> None: ...
+    def __get__(self, instance: Any, cls: Type[_Self] = ...) -> _Get: ...
+    def getter(self, method: Callable[[Type[_Self]], _Get]) -> classproperty[_Get]: ...

tests/typecheck/managers/test_managers.yml

@@ -48,7 +48,7 @@
                 class Base(Generic[_T]):
                     def __init__(self, model_cls: Type[_T]):
                         self.model_cls = model_cls
-                        reveal_type(self.model_cls._default_manager)  # N: Revealed type is "django.db.models.manager.BaseManager[django.db.models.base.Model]"
+                        reveal_type(self.model_cls._default_manager)  # N: Revealed type is "django.db.models.manager.BaseManager[_T`1]"
                 class MyModel(models.Model):
                     pass
                 class Child(Base[MyModel]):