Fixed #36092 -- Disallowed non-local fields in composite primary keys.

django/db/models/base.py

@@ -1803,6 +1803,8 @@ class Model(AltersData, metaclass=ModelBase):
                 hint = f"{field_name!r} field may not set 'null=True'."
             elif field.generated:
                 hint = f"{field_name!r} field is a generated field."
+            elif field not in meta.local_fields:
+                hint = f"{field_name!r} field is not a local field."
             else:
                 seen_columns[field.column].append(field_name)
 

tests/composite_pk/test_checks.py

@@ -247,3 +247,24 @@ class CompositePKChecksTests(TestCase):
                 ),
             ],
         )
+
+    def test_composite_pk_cannot_include_non_local_field(self):
+        class Foo(models.Model):
+            a = models.SmallIntegerField()
+
+        class Bar(Foo):
+            pk = models.CompositePrimaryKey("a", "b")
+            b = models.SmallIntegerField()
+
+        self.assertEqual(Foo.check(databases=self.databases), [])
+        self.assertEqual(
+            Bar.check(databases=self.databases),
+            [
+                checks.Error(
+                    "'a' cannot be included in the composite primary key.",
+                    hint="'a' field is not a local field.",
+                    obj=Bar,
+                    id="models.E042",
+                ),
+            ],
+        )