[1.2.X] Fixed #12687 -- fixed an issue with aggregates and counts in conjunction with annotations where the QuerySet was provably empty. Backport of [14586].

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@14587 bcc190cf-cafb-0310-a4f2-bffc1f526a37

1 files changed, 18 insertions, 0 deletions

diff --git a/tests/regressiontests/aggregation_regress/tests.py b/tests/regressiontests/aggregation_regress/tests.py
index 58d0b2748f..2429ffec94 100644
--- a/tests/regressiontests/aggregation_regress/tests.py
+++ b/tests/regressiontests/aggregation_regress/tests.py
@@ -641,6 +641,24 @@ class AggregationTests(TestCase):
             lambda: Book.objects.annotate(mean_age=Avg('authors__age')).annotate(Avg('mean_age'))
         )
 
+    def test_empty_filter_count(self):
+        self.assertEqual(
+            Author.objects.filter(id__in=[]).annotate(Count("friends")).count(),
+            0
+        )
+
+    def test_empty_filter_aggregate(self):
+        self.assertEqual(
+            Author.objects.filter(id__in=[]).annotate(Count("friends")).aggregate(Count("pk")),
+            {"pk__count": None}
+        )
+
+    def test_annotate_and_join(self):
+        self.assertEqual(
+            Author.objects.annotate(c=Count("friends__name")).exclude(friends__name="Joe").count(),
+            Author.objects.count()
+        )
+
     if run_stddev_tests():
         def test_stddev(self):
             self.assertEqual(