Fixed #36433 -- Fixed constraint validation crash when condition uses a ForeignKey attname.

Regression in e44e8327d3.

Thank you to Jacob Walls for the report.

Co-authored-by: Simon Charette <charette.s@gmail.com>

django/db/models/base.py

@@ -1322,6 +1322,7 @@ class Model(AltersData, metaclass=ModelBase):
             if not value or not hasattr(value, "resolve_expression"):
                 value = Value(value, field)
             field_map[field.name] = value
+            field_map[field.attname] = value
         if "pk" not in exclude:
             field_map["pk"] = Value(self.pk, meta.pk)
         if generated_fields:

tests/constraints/tests.py

@@ -361,6 +361,22 @@ class CheckConstraintTests(TestCase):
             constraint_with_pk.validate(ChildModel, ChildModel(id=1, age=1))
         constraint_with_pk.validate(ChildModel, ChildModel(pk=1, age=1), exclude={"pk"})
 
+    def test_validate_fk_attname(self):
+        constraint_with_fk = models.CheckConstraint(
+            condition=models.Q(uniqueconstraintproduct_ptr_id__isnull=False),
+            name="parent_ptr_present",
+        )
+        with self.assertRaisesMessage(
+            ValidationError, "Constraint “parent_ptr_present” is violated."
+        ):
+            constraint_with_fk.validate(
+                ChildUniqueConstraintProduct, ChildUniqueConstraintProduct()
+            )
+        constraint_with_fk.validate(
+            ChildUniqueConstraintProduct,
+            ChildUniqueConstraintProduct(uniqueconstraintproduct_ptr_id=1),
+        )
+
     @skipUnlessDBFeature("supports_json_field")
     def test_validate_jsonfield_exact(self):
         data = {"release": "5.0.2", "version": "stable"}