Ticket #16715: wrong-join-test-r16910.patch

tests/regressiontests/model_inheritance_select_related/tests.py

@@ -2 +2 @@
 
 from django.test import TestCase
 
-from models import Restaurant, Person
+from models import Chain, Place, Restaurant, Franchise, FranchiseChainOptional, Person
 
 
 class ModelInheritanceSelectRelatedTests(TestCase):
@@ -27 +27 @@
 
         jane = Person.objects.order_by("name").select_related("favorite_restaurant")[0]
         self.assertEqual(jane.favorite_restaurant.name, "Craft")
+
+    def test_select_related_foreign_key(self):
+        # Regression test for #16715 (1/2)
+        c = Chain.objects.create()
+        p = Place.objects.create(name="SomePlace")
+        f = Franchise.objects.create(name="SomeFranchise", chain=c)
+
+        self.assertEqual(len(Place.objects.all()), 2)
+        self.assertEqual(len(Place.objects.select_related("franchise")), 2)
+        # In 16715 the following query silently dropped the place that
+        # was not a franchise due to selecting an INNER JOIN instead
+        # of LEFT OUTER JOIN when joining the Franchise and Chain
+        # tables.
+        self.assertEqual(len(Place.objects.select_related("franchise__chain")), 2)
+
+    def test_select_related_foreign_key_null(self):
+        # Regression test for #16715 (2/2)
+        c = Chain.objects.create()
+        p = Place.objects.create(name="SomePlace")
+        f = FranchiseChainOptional.objects.create(name="SomeFranchise", chain=c)
+
+        self.assertEqual(len(Place.objects.all()), 2)
+        self.assertEqual(len(Place.objects.select_related("franchisechainoptional")), 2)
+        # In 16715 the following query works as expected as attribute
+        # null=True on the chain foreign key forces the join back to
+        # LEFT OUTER JOIN in any case.
+        self.assertEqual(len(Place.objects.select_related("franchisechainoptional__chain")), 2)

tests/regressiontests/model_inheritance_select_related/models.py

@@ -5 +5 @@
 
 from django.db import models
 
+
+class Chain(models.Model):
+    pass
+
+
 class Place(models.Model):
     name = models.CharField(max_length=50)
 
@@ -14 +19 @@
     def __unicode__(self):
         return u"%s the place" % self.name
 
+
 class Restaurant(Place):
     serves_sushi = models.BooleanField()
     serves_steak = models.BooleanField()
@@ -21 +27 @@
     def __unicode__(self):
         return u"%s the restaurant" % self.name
 
+
+class Franchise(Place):
+    chain = models.ForeignKey(Chain)
+
+    def __unicode__(self):
+        return u"%s the franchise" % self.name
+
+class FranchiseChainOptional(Place):
+    chain = models.ForeignKey(Chain, null=True)
+
+    def __unicode__(self):
+        return u"%s the franchise (chain optional)" % self.name
+
+
 class Person(models.Model):
     name = models.CharField(max_length=50)
     favorite_restaurant = models.ForeignKey(Restaurant)