Commit e4c9ccdb authored by Andrew Godwin's avatar Andrew Godwin
Browse files

[1.7.x] Fixed #22889: Unneeded to_field in fk.deconstruct causing swap issues

parent 0dd737a7

django/db/models/fields/related.py

+2 −1
Original line number Diff line number Diff line
@@ -1652,7 +1652,8 @@ class ForeignKey(ForeignObject): 
        if self.rel.on_delete is not CASCADE:

            kwargs['on_delete'] = self.rel.on_delete

        # Rel needs more work.

        if self.rel.field_name:

        to_meta = getattr(self.rel.to, "_meta", None)

        if self.rel.field_name and (not to_meta or (to_meta.pk and self.rel.field_name != to_meta.pk.name)):

            kwargs['to_field'] = self.rel.field_name

        return name, path, args, kwargs

tests/field_deconstruction/tests.py

+9 −0
Original line number Diff line number Diff line
@@ -169,7 +169,10 @@ class FieldDeconstructionTests(TestCase): 


    def test_foreign_key(self):

        # Test basic pointing

        from django.contrib.auth.models import Permission

        field = models.ForeignKey("auth.Permission")

        field.rel.to = Permission

        field.rel.field_name = "id"

        name, path, args, kwargs = field.deconstruct()

        self.assertEqual(path, "django.db.models.ForeignKey")

        self.assertEqual(args, [])
@@ -194,6 +197,12 @@ class FieldDeconstructionTests(TestCase): 
        self.assertEqual(path, "django.db.models.ForeignKey")

        self.assertEqual(args, [])

        self.assertEqual(kwargs, {"to": "auth.User", "on_delete": models.SET_NULL})

        # Test to_field preservation

        field = models.ForeignKey("auth.Permission", to_field="foobar")

        name, path, args, kwargs = field.deconstruct()

        self.assertEqual(path, "django.db.models.ForeignKey")

        self.assertEqual(args, [])

        self.assertEqual(kwargs, {"to": "auth.Permission", "to_field": "foobar"})



    @override_settings(AUTH_USER_MODEL="auth.Permission")

    def test_foreign_key_swapped(self):