From 8b2c1ac06d3d1cf99661f4af75030abb456e1665 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Anssi=20K=C3=A4=C3=A4ri=C3=A4inen?= <akaariai@gmail.com>
Date: Tue, 28 Jan 2014 21:36:57 +0200
Subject: [PATCH] Added tests for m2m queries with custom pk on the end models

It seems this case was fixed somewhere between 1.5.x and 1.6.x. I added
tests as I wasn't able to find any tests for these cases. Refs #21879
---
 tests/queries/models.py |  6 ++++++
 tests/queries/tests.py  | 15 ++++++++++++++-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/tests/queries/models.py b/tests/queries/models.py
index cc952e8bfc..b38f672ea6 100644
--- a/tests/queries/models.py
+++ b/tests/queries/models.py
@@ -258,6 +258,12 @@ class CustomPk(models.Model):
 class Related(models.Model):
     custom = models.ForeignKey(CustomPk)
 
+
+class CustomPkTag(models.Model):
+    id = models.CharField(max_length=20, primary_key=True)
+    custom_pk = models.ManyToManyField(CustomPk)
+    tag = models.CharField(max_length=20)
+
 # An inter-related setup with a model subclass that has a nullable
 # path to another model, and a return path from that model.
 
diff --git a/tests/queries/tests.py b/tests/queries/tests.py
index b303d5f603..6bf90cdbf9 100644
--- a/tests/queries/tests.py
+++ b/tests/queries/tests.py
@@ -27,7 +27,7 @@ from .models import (
     BaseA, FK1, Identifier, Program, Channel, Page, Paragraph, Chapter, Book,
     MyObject, Order, OrderItem, SharedConnection, Task, Staff, StaffUser,
     CategoryRelationship, Ticket21203Parent, Ticket21203Child, Person,
-    Company, Employment)
+    Company, Employment, CustomPk, CustomPkTag)
 
 
 class BaseQuerysetTest(TestCase):
@@ -3243,3 +3243,16 @@ class ForeignKeyToBaseExcludeTests(TestCase):
             SpecialCategory.objects.filter(categoryitem__id=c1.pk),
             [sc1], lambda x: x
         )
+
+
+class ReverseM2MCustomPkTests(TestCase):
+    def test_ticket_21879(self):
+        cpt1 = CustomPkTag.objects.create(id='cpt1', tag='cpt1')
+        cp1 = CustomPk.objects.create(name='cp1', extra='extra')
+        cp1.custompktag_set.add(cpt1)
+        self.assertQuerysetEqual(
+            CustomPk.objects.filter(custompktag=cpt1), [cp1],
+            lambda x: x)
+        self.assertQuerysetEqual(
+            CustomPkTag.objects.filter(custom_pk=cp1), [cpt1],
+            lambda x: x)