Fixed #15709 - Duplicated group_by condition

Thanks to ziangsong for report, and to mk for the patch

git-svn-id: http://code.djangoproject.com/svn/django/trunk@16180 bcc190cf-cafb-0310-a4f2-bffc1f526a37

1 files changed, 6 insertions, 0 deletions

diff --git a/tests/regressiontests/aggregation_regress/tests.py b/tests/regressiontests/aggregation_regress/tests.py
index 0bb68991ea..14104210af 100644
--- a/tests/regressiontests/aggregation_regress/tests.py
+++ b/tests/regressiontests/aggregation_regress/tests.py
@@ -462,6 +462,12 @@ class AggregationTests(TestCase):
             lambda b: b.name
         )
 
+        # Regression for #15709 - Ensure each group_by field only exists once
+        # per query
+        qs = Book.objects.values('publisher').annotate(max_pages=Max('pages')).order_by()
+        grouping, gb_params = qs.query.get_compiler(qs.db).get_grouping()
+        self.assertEqual(len(grouping), 1)
+
     def test_duplicate_alias(self):
         # Regression for #11256 - duplicating a default alias raises ValueError.
         self.assertRaises(ValueError, Book.objects.all().annotate, Avg('authors__age'), authors__age__avg=Avg('authors__age'))