ORM generating incorrect query for through-model on <RelatedManager>.all()

[Arthur Pemberton]

I have a through-model which itself has a through model (because it needs a many-to-many relationship). The problem comes when i try to get related mode through this many-to-many relationship. The ORM generates the WHERE clause on the wrong field (the pk, instead of the fk).

-- generated sql
SELECT "core_role"."id", "core_role"."name"
FROM "core_role"
INNER JOIN "core_dealercontactrole" ON ( "core_role"."id" = "core_dealercontactrole"."role_id" )
WHERE "core_dealercontactrole"."id" = 8743
ORDER BY "core_role"."name" ASC

-- corrected sql
SELECT "core_role"."id", "core_role"."name"
FROM "core_role"
INNER JOIN "core_dealercontactrole" ON ( "core_role"."id" = "core_dealercontactrole"."role_id" )
WHERE "core_dealercontactrole"."dealercontact_id" = 8743
ORDER BY "core_role"."name" ASC

The code that generated the query:

dc = DealerContact.objects.get(id=8743)
>>> unicode(dc.roles.all().query)
u'SELECT "core_role"."id", "core_role"."name" FROM "core_role" INNER JOIN "core_dealercontactrole" ON ( "core_role"."id" = "core_dealercontactrole"."role_id" ) WHERE "core_dealercontactrole"."id" = 8743 ORDER BY "core_role"."name" ASC'

Here are the models (with superfluous fields removed):

class Contact(models.Model):

        first_name = models.CharField(blank=True, max_length=50)
        last_name = models.CharField(blank=True, max_length=50)

        class Meta:
                ordering = ('last_name','first_name')

        pass

class Dealer(models.Model):

        contacts = models.ManyToManyField('Contact', through='DealerContact', related_name='dealers')
        
        name = models.CharField(db_index=True, max_length=250)

        pass

class DealerContact(models.Model):

        dealer = models.ForeignKey('Dealer', related_name='dealercontacts+', on_delete=models.CASCADE)
        contact = models.ForeignKey('Contact', related_name='+', on_delete=models.CASCADE)
        roles = models.ManyToManyField('Role', through='DealerContactRole', related_name='+')

        class Meta:
                unique_together = ('dealer','contact')

        pass

class DealerContactRole(models.Model):

        dealercontact = models.ForeignKey('DealerContact', related_name='+', on_delete=models.CASCADE)
        role = models.ForeignKey('Role', related_name='+')

        class Meta:
                unique_together = ('dealercontact','role')

        pass

class Role(models.Model):

        name = models.CharField(db_index=True, max_length=100)

        class Meta:
                ordering = ('name',)

        pass