Fixed #19580 -- Unified behavior of reverse foreign key and many-to-many relations for unsaved instances.

1 files changed, 33 insertions, 0 deletions

diff --git a/tests/many_to_one_null/tests.py b/tests/many_to_one_null/tests.py
index 5bd06b1ac4..f92d49f0a9 100644
--- a/tests/many_to_one_null/tests.py
+++ b/tests/many_to_one_null/tests.py
@@ -146,3 +146,36 @@ class ManyToOneNullTests(TestCase):
         self.assertIs(d1.car, None)
         with self.assertNumQueries(0):
             self.assertEqual(list(c1.drivers.all()), [])
+
+    def test_unsaved(self):
+        msg = (
+            "'Car' instance needs to have a primary key value before this relationship "
+            "can be used."
+        )
+        with self.assertRaisesMessage(ValueError, msg):
+            Car(make="Ford").drivers.all()
+
+    def test_related_null_to_field_related_managers(self):
+        car = Car.objects.create(make=None)
+        driver = Driver.objects.create()
+        msg = (
+            f'"{car!r}" needs to have a value for field "make" before this '
+            f"relationship can be used."
+        )
+        with self.assertRaisesMessage(ValueError, msg):
+            car.drivers.add(driver)
+        with self.assertRaisesMessage(ValueError, msg):
+            car.drivers.create()
+        with self.assertRaisesMessage(ValueError, msg):
+            car.drivers.get_or_create()
+        with self.assertRaisesMessage(ValueError, msg):
+            car.drivers.update_or_create()
+        with self.assertRaisesMessage(ValueError, msg):
+            car.drivers.remove(driver)
+        with self.assertRaisesMessage(ValueError, msg):
+            car.drivers.clear()
+        with self.assertRaisesMessage(ValueError, msg):
+            car.drivers.set([driver])
+
+        with self.assertNumQueries(0):
+            self.assertEqual(car.drivers.count(), 0)