[1.2.X] Fixed #15161 - Corrected handling of ManyToManyField with through table using to_field on its ForeignKeys. Thanks to adehnert for the report.

Backport of r15330 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@15331 bcc190cf-cafb-0310-a4f2-bffc1f526a37

2 files changed, 43 insertions, 1 deletions

diff --git a/tests/regressiontests/m2m_through_regress/models.py b/tests/regressiontests/m2m_through_regress/models.py
index ec87985765..121ef22470 100644
--- a/tests/regressiontests/m2m_through_regress/models.py
+++ b/tests/regressiontests/m2m_through_regress/models.py
@@ -53,3 +53,25 @@ class Through(ThroughBase):
 class B(models.Model):
     b_text = models.CharField(max_length=20)
     a_list = models.ManyToManyField(A, through=Through)
+
+
+# Using to_field on the through model
+class Car(models.Model):
+    make = models.CharField(max_length=20, unique=True)
+    drivers = models.ManyToManyField('Driver', through='CarDriver')
+
+    def __unicode__(self, ):
+        return self.make
+
+class Driver(models.Model):
+    name = models.CharField(max_length=20, unique=True)
+
+    def __unicode__(self, ):
+        return self.name
+
+class CarDriver(models.Model):
+    car = models.ForeignKey('Car', to_field='make')
+    driver = models.ForeignKey('Driver', to_field='name')
+
+    def __unicode__(self, ):
+        return u"pk=%s car=%s driver=%s" % (str(self.pk), self.car, self.driver)
diff --git a/tests/regressiontests/m2m_through_regress/tests.py b/tests/regressiontests/m2m_through_regress/tests.py
index 2eaf8861fc..a79651a4a1 100644
--- a/tests/regressiontests/m2m_through_regress/tests.py
+++ b/tests/regressiontests/m2m_through_regress/tests.py
@@ -7,7 +7,8 @@ from django.core import management
 from django.contrib.auth.models import User
 from django.test import TestCase
 
-from models import Person, Group, Membership, UserMembership
+from models import (Person, Group, Membership, UserMembership,
+                    Car, Driver, CarDriver)
 
 
 class M2MThroughTestCase(TestCase):
@@ -118,6 +119,25 @@ class M2MThroughTestCase(TestCase):
             ]
         )
 
+
+class ToFieldThroughTests(TestCase):
+    def setUp(self):
+        self.car = Car.objects.create(make="Toyota")
+        self.driver = Driver.objects.create(name="Ryan Briscoe")
+        CarDriver.objects.create(car=self.car, driver=self.driver)
+
+    def test_to_field(self):
+        self.assertQuerysetEqual(
+            self.car.drivers.all(),
+            ["<Driver: Ryan Briscoe>"]
+            )
+
+    def test_to_field_reverse(self):
+        self.assertQuerysetEqual(
+            self.driver.car_set.all(),
+            ["<Car: Toyota>"]
+            )
+
 class ThroughLoadDataTestCase(TestCase):
     fixtures = ["m2m_through"]