Refs #24201 -- Ignored order_with_respect_to private fields in migrations.

Thanks Tim for the review.

django/db/migrations/state.py

@@ -443,6 +443,9 @@ class ModelState(object):
             for key in ["unique_together", "index_together", "order_with_respect_to"]:
                 if key in options:
                     del options[key]
+        # Private fields are ignored, so remove options that refer to them.
+        elif options.get('order_with_respect_to') in {field.name for field in model._meta.private_fields}:
+            del options['order_with_respect_to']
 
         def flatten_bases(model):
             bases = []

tests/migrations/test_state.py

@@ -9,6 +9,7 @@ from django.db.migrations.state import (
     ModelState, ProjectState, get_related_models_recursive,
 )
 from django.test import SimpleTestCase, override_settings
+from django.test.utils import isolate_apps
 from django.utils import six
 
 from .models import (
@@ -911,6 +912,19 @@ class ModelStateTests(SimpleTestCase):
         self.assertEqual([name for name, mgr in food_state.managers], ['food_mgr'])
         self.assertEqual(food_state.managers[0][1].args, ('a', 'b', 1, 2))
 
+    @isolate_apps('migrations', 'django.contrib.contenttypes')
+    def test_order_with_respect_to_private_field(self):
+        class PrivateFieldModel(models.Model):
+            content_type = models.ForeignKey('contenttypes.ContentType', models.CASCADE)
+            object_id = models.PositiveIntegerField()
+            private = GenericForeignKey()
+
+            class Meta:
+                order_with_respect_to = 'private'
+
+        state = ModelState.from_model(PrivateFieldModel)
+        self.assertNotIn('order_with_respect_to', state.options)
+
 
 class RelatedModelsTests(SimpleTestCase):