Fixed #26706 -- Made RelatedManager modification methods clear prefetch_related() cache.

3 files changed, 80 insertions, 1 deletions

diff --git a/tests/many_to_many/tests.py b/tests/many_to_many/tests.py
index 86ffe816eb..2d35266f46 100644
--- a/tests/many_to_many/tests.py
+++ b/tests/many_to_many/tests.py
@@ -518,6 +518,40 @@ class ManyToManyTests(TestCase):
         self.assertQuerysetEqual(self.a4.publications.all(), [])
         self.assertQuerysetEqual(self.p2.article_set.all(), ['<Article: NASA finds intelligent life on Earth>'])
 
+    def test_clear_after_prefetch(self):
+        a4 = Article.objects.prefetch_related('publications').get(id=self.a4.id)
+        self.assertQuerysetEqual(a4.publications.all(), ['<Publication: Science News>'])
+        a4.publications.clear()
+        self.assertQuerysetEqual(a4.publications.all(), [])
+
+    def test_remove_after_prefetch(self):
+        a4 = Article.objects.prefetch_related('publications').get(id=self.a4.id)
+        self.assertQuerysetEqual(a4.publications.all(), ['<Publication: Science News>'])
+        a4.publications.remove(self.p2)
+        self.assertQuerysetEqual(a4.publications.all(), [])
+
+    def test_add_after_prefetch(self):
+        a4 = Article.objects.prefetch_related('publications').get(id=self.a4.id)
+        self.assertEqual(a4.publications.count(), 1)
+        a4.publications.add(self.p1)
+        self.assertEqual(a4.publications.count(), 2)
+
+    def test_set_after_prefetch(self):
+        a4 = Article.objects.prefetch_related('publications').get(id=self.a4.id)
+        self.assertEqual(a4.publications.count(), 1)
+        a4.publications.set([self.p2, self.p1])
+        self.assertEqual(a4.publications.count(), 2)
+        a4.publications.set([self.p1])
+        self.assertEqual(a4.publications.count(), 1)
+
+    def test_add_then_remove_after_prefetch(self):
+        a4 = Article.objects.prefetch_related('publications').get(id=self.a4.id)
+        self.assertEqual(a4.publications.count(), 1)
+        a4.publications.add(self.p1)
+        self.assertEqual(a4.publications.count(), 2)
+        a4.publications.remove(self.p1)
+        self.assertQuerysetEqual(a4.publications.all(), ['<Publication: Science News>'])
+
     def test_inherited_models_selects(self):
         """
         #24156 - Objects from child models where the parent's m2m field uses
diff --git a/tests/many_to_one/models.py b/tests/many_to_one/models.py
index 05491e99f1..abc9c7d826 100644
--- a/tests/many_to_one/models.py
+++ b/tests/many_to_one/models.py
@@ -43,7 +43,7 @@ class City(models.Model):
 
 @python_2_unicode_compatible
 class District(models.Model):
-    city = models.ForeignKey(City, models.CASCADE)
+    city = models.ForeignKey(City, models.CASCADE, related_name='districts', null=True)
     name = models.CharField(max_length=50)
 
     def __str__(self):
diff --git a/tests/many_to_one/tests.py b/tests/many_to_one/tests.py
index 20f2e0d56d..0de6973bb8 100644
--- a/tests/many_to_one/tests.py
+++ b/tests/many_to_one/tests.py
@@ -624,3 +624,48 @@ class ManyToOneTests(TestCase):
         # doesn't exist should be an instance of a subclass of `AttributeError`
         # refs #21563
         self.assertFalse(hasattr(Article(), 'reporter'))
+
+    def test_clear_after_prefetch(self):
+        c = City.objects.create(name='Musical City')
+        District.objects.create(name='Ladida', city=c)
+        city = City.objects.prefetch_related('districts').get(id=c.id)
+        self.assertQuerysetEqual(city.districts.all(), ['<District: Ladida>'])
+        city.districts.clear()
+        self.assertQuerysetEqual(city.districts.all(), [])
+
+    def test_remove_after_prefetch(self):
+        c = City.objects.create(name='Musical City')
+        d = District.objects.create(name='Ladida', city=c)
+        city = City.objects.prefetch_related('districts').get(id=c.id)
+        self.assertQuerysetEqual(city.districts.all(), ['<District: Ladida>'])
+        city.districts.remove(d)
+        self.assertQuerysetEqual(city.districts.all(), [])
+
+    def test_add_after_prefetch(self):
+        c = City.objects.create(name='Musical City')
+        District.objects.create(name='Ladida', city=c)
+        d2 = District.objects.create(name='Ladidu')
+        city = City.objects.prefetch_related('districts').get(id=c.id)
+        self.assertEqual(city.districts.count(), 1)
+        city.districts.add(d2)
+        self.assertEqual(city.districts.count(), 2)
+
+    def test_set_after_prefetch(self):
+        c = City.objects.create(name='Musical City')
+        District.objects.create(name='Ladida', city=c)
+        d2 = District.objects.create(name='Ladidu')
+        city = City.objects.prefetch_related('districts').get(id=c.id)
+        self.assertEqual(city.districts.count(), 1)
+        city.districts.set([d2])
+        self.assertQuerysetEqual(city.districts.all(), ['<District: Ladidu>'])
+
+    def test_add_then_remove_after_prefetch(self):
+        c = City.objects.create(name='Musical City')
+        District.objects.create(name='Ladida', city=c)
+        d2 = District.objects.create(name='Ladidu')
+        city = City.objects.prefetch_related('districts').get(id=c.id)
+        self.assertEqual(city.districts.count(), 1)
+        city.districts.add(d2)
+        self.assertEqual(city.districts.count(), 2)
+        city.districts.remove(d2)
+        self.assertEqual(city.districts.count(), 1)