Fixed #36481 -- Fixed QuerySet.update concrete fields check.

FieldError is now emitted for invalid update calls involving reverse
relations, where previously they failed with AttributeError.

django/db/models/sql/subqueries.py

@@ -87,15 +87,12 @@ class UpdateQuery(Query):
         values_seq = []
         for name, val in values.items():
             field = self.get_meta().get_field(name)
-            direct = (
-                not (field.auto_created and not field.concrete) or not field.concrete
-            )
             model = field.model._meta.concrete_model
             if field.name == "pk" and model._meta.is_composite_pk:
                 raise FieldError(
                     "Composite primary key fields must be updated individually."
                 )
-            if not direct or (field.is_relation and field.many_to_many):
+            if not field.concrete or (field.is_relation and field.many_to_many):
                 raise FieldError(
                     "Cannot update model field %r (only non-relations and "
                     "foreign keys permitted)." % field

tests/composite_pk/test_update.py

@@ -169,13 +169,16 @@ class CompositePKUpdateTests(TestCase):
         token_3 = Token.objects.get(pk=self.token_3.pk)
         self.assertEqual(token_3.secret, "bar")
 
-    def test_cant_update_to_unsaved_object(self):
+    def test_cant_update_relation(self):
         msg = (
-            "Unsaved model instance <User: User object ((None, None))> cannot be used "
-            "in an ORM query."
+            "Cannot update model field <django.db.models.fields.related.ForeignObject: "
+            "user> (only non-relations and foreign keys permitted)"
         )
 
-        with self.assertRaisesMessage(ValueError, msg):
+        with self.assertRaisesMessage(FieldError, msg):
+            Comment.objects.update(user=self.user_1)
+
+        with self.assertRaisesMessage(FieldError, msg):
             Comment.objects.update(user=User())
 
     def test_cant_update_pk_field(self):

tests/update/models.py

@@ -41,6 +41,9 @@ class Foo(models.Model):
 
 class Bar(models.Model):
     foo = models.ForeignKey(Foo, models.CASCADE, to_field="target")
+    o2o_foo = models.OneToOneField(
+        Foo, models.CASCADE, related_name="o2o_bar", null=True
+    )
     m2m_foo = models.ManyToManyField(Foo, related_name="m2m_foo")
     x = models.IntegerField(default=0)
 

tests/update/tests.py

@@ -173,6 +173,30 @@ class AdvancedTests(TestCase):
         with self.assertRaisesMessage(FieldError, msg):
             Foo.objects.update(m2m_foo="whatever")
 
+    def test_update_reverse_fk_descriptor(self):
+        msg = (
+            "Cannot update model field <ManyToOneRel: update.bar> "
+            "(only non-relations and foreign keys permitted)."
+        )
+        with self.assertRaisesMessage(FieldError, msg):
+            Foo.objects.update(bar="whatever")
+
+    def test_update_reverse_o2o_descriptor(self):
+        msg = (
+            "Cannot update model field <OneToOneRel: update.bar> "
+            "(only non-relations and foreign keys permitted)."
+        )
+        with self.assertRaisesMessage(FieldError, msg):
+            Foo.objects.update(o2o_bar="whatever")
+
+    def test_update_reverse_mti_parent_link_descriptor(self):
+        msg = (
+            "Cannot update model field <OneToOneRel: update.uniquenumberchild> "
+            "(only non-relations and foreign keys permitted)."
+        )
+        with self.assertRaisesMessage(FieldError, msg):
+            UniqueNumber.objects.update(uniquenumberchild="whatever")
+
     def test_update_transformed_field(self):
         A.objects.create(x=5)
         A.objects.create(x=-6)