id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
30355	Specifying custom manager doesn't work with prefetch	Kyle Mulka	Akash Kumar Sen	"When using prefetch and specifying a custom manager to use for a reverse relation, Django doesn't filter correctly. Here's an example:

{{{
class Business(models.Model):
    name = models.CharField(max_length=255)

    def approved_reviews(self):
        return self.review_set(manager='approved_reviews').all()


class ApprovedReviewsManager(models.Manager):
    def get_queryset(self):
        return super().get_queryset().filter(status=Review.APPROVED)


class Review(models.Model):
    NEW = 1
    APPROVED = 2
    STATUS_CHOICES = (
        (NEW, 'New'),
        (APPROVED, 'Approved'),
    )
    business = models.ForeignKey(Business)
    text = models.CharField(max_length=255)
    status = models.IntegerField(choices=STATUS_CHOICES, default=NEW)

    objects = models.Manager()
    approved_reviews = ApprovedReviewsManager()


class ApprovedReviewsTest(TestCase):
    def test_with_prefetch(self):
        business = Business()
        business.save()

        review = Review()
        review.business = business
        review.save()

        businesses = Business.objects.prefetch_related('review_set').all()

        business = businesses[0]
        approved_reviews = business.review_set(manager='approved_reviews').all()

        self.assertEqual(len(approved_reviews), 0)
}}}

The full test project is available here: https://github.com/mulka/django_prefetch_manager_bug/blob/master/review_site/tests.py
"	Cleanup/optimization	closed	Documentation	dev	Normal	fixed		Kourt Bailey Akash Kumar Sen	Ready for checkin	1	0	0	0	0	0