Fixed #12247 -- Corrected the way update queries are processed when the update only refers to attributes on a base class. Thanks to jsmullyan for the report, and matiasb for the fix.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12910 bcc190cf-cafb-0310-a4f2-bffc1f526a37

tests/modeltests/update/tests.py

@@ -0,0 +1,49 @@
+from django.test import TestCase
+
+from models import A, B, D
+
+class SimpleTest(TestCase):
+    def setUp(self):
+        self.a1 = A.objects.create()
+        self.a2 = A.objects.create()
+        for x in range(20):
+            B.objects.create(a=self.a1)
+            D.objects.create(a=self.a1)
+
+    def test_nonempty_update(self):
+        """
+        Test that update changes the right number of rows for a nonempty queryset
+        """
+        num_updated = self.a1.b_set.update(y=100)
+        self.failUnlessEqual(num_updated, 20)
+        cnt = B.objects.filter(y=100).count()
+        self.failUnlessEqual(cnt, 20)
+
+    def test_empty_update(self):
+        """
+        Test that update changes the right number of rows for an empty queryset
+        """
+        num_updated = self.a2.b_set.update(y=100)
+        self.failUnlessEqual(num_updated, 0)
+        cnt = B.objects.filter(y=100).count()
+        self.failUnlessEqual(cnt, 0)
+
+    def test_nonempty_update_with_inheritance(self):
+        """
+        Test that update changes the right number of rows for an empty queryset
+        when the update affects only a base table
+        """
+        num_updated = self.a1.d_set.update(y=100)
+        self.failUnlessEqual(num_updated, 20)
+        cnt = D.objects.filter(y=100).count()
+        self.failUnlessEqual(cnt, 20)
+
+    def test_empty_update_with_inheritance(self):
+        """
+        Test that update changes the right number of rows for an empty queryset
+        when the update affects only a base table
+        """
+        num_updated = self.a2.d_set.update(y=100)
+        self.failUnlessEqual(num_updated, 0)
+        cnt = D.objects.filter(y=100).count()
+        self.failUnlessEqual(cnt, 0)