Commit 08014fe7 authored by Alex Hill's avatar Alex Hill Committed by Tim Graham
Browse files

Fixed #26686 -- Fixed crash when registering model signals with abstract senders.

parent 2c90981c

django/db/models/signals.py

+7 −6
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ from functools import partial 


from django.db.models.utils import make_model_tuple

from django.dispatch import Signal

from django.utils import six

from django.utils.deprecation import RemovedInDjango20Warning
@@ -15,15 +16,15 @@ class ModelSignal(Signal): 
    of the `app_label.ModelName` form.

    """

    def _lazy_method(self, method, apps, receiver, sender, **kwargs):

        from django.db.models.options import Options



        # This partial takes a single optional argument named "sender".

        partial_method = partial(method, receiver, **kwargs)

        # import models here to avoid a circular import

        from django.db import models

        if isinstance(sender, models.Model) or sender is None:

            # Skip lazy_model_operation to get a return value for disconnect()

            return partial_method(sender)

        apps = apps or models.base.Options.default_apps

        if isinstance(sender, six.string_types):

            apps = apps or Options.default_apps

            apps.lazy_model_operation(partial_method, make_model_tuple(sender))

        else:

            return partial_method(sender)



    def connect(self, receiver, sender=None, weak=True, dispatch_uid=None, apps=None):

        self._lazy_method(super(ModelSignal, self).connect, apps, receiver, sender, dispatch_uid=dispatch_uid)

tests/signals/tests.py

+12 −0
Original line number Diff line number Diff line 
from __future__ import unicode_literals



from django.apps.registry import Apps

from django.db import models

from django.db.models import signals

from django.dispatch import receiver
@@ -317,3 +318,14 @@ class LazyModelRefTest(BaseSignalTest): 


        Created()

        self.assertEqual(received, [])



    def test_register_model_class_senders_immediately(self):

        """

        Model signals registered with model classes as senders don't use the

        Apps.lazy_model_operation() mechanism.

        """

        # Book isn't registered with apps2, so it will linger in

        # apps2._pending_operations if ModelSignal does the wrong thing.

        apps2 = Apps()

        signals.post_init.connect(self.receiver, sender=Book, apps=apps2)

        self.assertEqual(list(apps2._pending_operations), [])