Fixed #17002 -- Allowed using a ManyToManyField through model that inherits another.

2 files changed, 80 insertions, 0 deletions

diff --git a/tests/m2m_through_regress/models.py b/tests/m2m_through_regress/models.py
index 10dcddfc58..adde24dcf9 100644
--- a/tests/m2m_through_regress/models.py
+++ b/tests/m2m_through_regress/models.py
@@ -94,3 +94,32 @@ class CarDriver(models.Model):
 
     def __str__(self):
         return "pk=%s car=%s driver=%s" % (str(self.pk), self.car, self.driver)
+
+
+# Through models using multi-table inheritance
+class Event(models.Model):
+    name = models.CharField(max_length=50, unique=True)
+    people = models.ManyToManyField('Person', through='IndividualCompetitor')
+    special_people = models.ManyToManyField(
+        'Person',
+        through='ProxiedIndividualCompetitor',
+        related_name='special_event_set',
+    )
+    teams = models.ManyToManyField('Group', through='CompetingTeam')
+
+
+class Competitor(models.Model):
+    event = models.ForeignKey(Event, models.CASCADE)
+
+
+class IndividualCompetitor(Competitor):
+    person = models.ForeignKey(Person, models.CASCADE)
+
+
+class CompetingTeam(Competitor):
+    team = models.ForeignKey(Group, models.CASCADE)
+
+
+class ProxiedIndividualCompetitor(IndividualCompetitor):
+    class Meta:
+        proxy = True
diff --git a/tests/m2m_through_regress/test_multitable.py b/tests/m2m_through_regress/test_multitable.py
new file mode 100644
index 0000000000..f07af40f6d
--- /dev/null
+++ b/tests/m2m_through_regress/test_multitable.py
@@ -0,0 +1,51 @@
+from __future__ import unicode_literals
+
+from django.test import TestCase
+
+from .models import (
+    CompetingTeam, Event, Group, IndividualCompetitor, Membership, Person,
+)
+
+
+class MultiTableTests(TestCase):
+    @classmethod
+    def setUpTestData(cls):
+        cls.alice = Person.objects.create(name='Alice')
+        cls.bob = Person.objects.create(name='Bob')
+        cls.chris = Person.objects.create(name='Chris')
+        cls.dan = Person.objects.create(name='Dan')
+        cls.team_alpha = Group.objects.create(name='Alpha')
+        Membership.objects.create(person=cls.alice, group=cls.team_alpha)
+        Membership.objects.create(person=cls.bob, group=cls.team_alpha)
+        cls.event = Event.objects.create(name='Exposition Match')
+        IndividualCompetitor.objects.create(event=cls.event, person=cls.chris)
+        IndividualCompetitor.objects.create(event=cls.event, person=cls.dan)
+        CompetingTeam.objects.create(event=cls.event, team=cls.team_alpha)
+
+    def test_m2m_query(self):
+        result = self.event.teams.all()
+        self.assertCountEqual(result, [self.team_alpha])
+
+    def test_m2m_reverse_query(self):
+        result = self.chris.event_set.all()
+        self.assertCountEqual(result, [self.event])
+
+    def test_m2m_query_proxied(self):
+        result = self.event.special_people.all()
+        self.assertCountEqual(result, [self.chris, self.dan])
+
+    def test_m2m_reverse_query_proxied(self):
+        result = self.chris.special_event_set.all()
+        self.assertCountEqual(result, [self.event])
+
+    def test_m2m_prefetch_proxied(self):
+        result = Event.objects.filter(name='Exposition Match').prefetch_related('special_people')
+        with self.assertNumQueries(2):
+            self.assertCountEqual(result, [self.event])
+            self.assertEqual(sorted([p.name for p in result[0].special_people.all()]), ['Chris', 'Dan'])
+
+    def test_m2m_prefetch_reverse_proxied(self):
+        result = Person.objects.filter(name='Dan').prefetch_related('special_event_set')
+        with self.assertNumQueries(2):
+            self.assertCountEqual(result, [self.dan])
+            self.assertEqual([event.name for event in result[0].special_event_set.all()], ['Exposition Match'])