Commit ba53da89 authored by Anderson Resende's avatar Anderson Resende Committed by Tim Graham
Browse files

Fixed #26796 -- Added a system check for m2m fields with ignored limit_choices_to.

parent 8a4f017f

django/db/models/fields/related.py

+9 −0
Original line number Diff line number Diff line
@@ -1228,6 +1228,15 @@ class ManyToManyField(RelatedField): 
                    id='fields.W341',

                )

            )

        if self.remote_field.limit_choices_to and self.remote_field.through:

            warnings.append(

                checks.Warning(

                    'limit_choices_to has no effect on ManyToManyField '

                    'with a through model.',

                    obj=self,

                    id='fields.W343',

                )

            )



        return warnings

docs/ref/checks.txt

+2 −0
Original line number Diff line number Diff line
@@ -251,6 +251,8 @@ Related Fields 
* **fields.W341**: ``ManyToManyField`` does not support ``validators``.

* **fields.W342**: Setting ``unique=True`` on a ``ForeignKey`` has the same

  effect as using a ``OneToOneField``.

* **fields.W343**: ``limit_choices_to`` has no effect on ``ManyToManyField``

  with a ``through`` model.



Signals

~~~~~~~

tests/invalid_models_tests/test_relative_fields.py

+21 −6
Original line number Diff line number Diff line
@@ -181,7 +181,18 @@ class RelativeFieldTests(SimpleTestCase): 
            name = models.CharField(max_length=20)



        class ModelM2M(models.Model):

            m2m = models.ManyToManyField(Model, null=True, validators=[''])

            m2m = models.ManyToManyField(

                Model,

                null=True,

                validators=[''],

                limit_choices_to={'name': 'test_name'},

                through='ThroughModel',

                through_fields=('modelm2m', 'model'),

            )



        class ThroughModel(models.Model):

            model = models.ForeignKey('Model', models.CASCADE)

            modelm2m = models.ForeignKey('ModelM2M', models.CASCADE)



        errors = ModelM2M.check()

        field = ModelM2M._meta.get_field('m2m')
@@ -191,15 +202,19 @@ class RelativeFieldTests(SimpleTestCase): 
                'null has no effect on ManyToManyField.',

                obj=field,

                id='fields.W340',

            )

        ]

        expected.append(

            ),

            DjangoWarning(

                'ManyToManyField does not support validators.',

                obj=field,

                id='fields.W341',

            )

        )

            ),

            DjangoWarning(

                'limit_choices_to has no effect on ManyToManyField '

                'with a through model.',

                obj=field,

                id='fields.W343',

            ),

        ]



        self.assertEqual(errors, expected)