Fixed #13935, added support for using QuerySet.dates across related fields. Thanks to valyagolev for his work on the patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@14461 bcc190cf-cafb-0310-a4f2-bffc1f526a37

tests/regressiontests/dates/tests.py

@@ -0,0 +1,81 @@
+from datetime import datetime
+
+from django.test import TestCase
+
+from models import Article, Comment, Category
+
+
+class DatesTests(TestCase):
+    def test_related_model_traverse(self):
+        a1 = Article.objects.create(
+            title="First one",
+            pub_date=datetime(2005, 7, 28),
+        )
+        a2 = Article.objects.create(
+            title="Another one",
+            pub_date=datetime(2010, 7, 28),
+        )
+        a3 = Article.objects.create(
+            title="Third one, in the first day",
+            pub_date=datetime(2005, 7, 28),
+        )
+
+        a1.comments.create(
+            text="Im the HULK!",
+            pub_date=datetime(2005, 7, 28),
+        )
+        a1.comments.create(
+            text="HULK SMASH!",
+            pub_date=datetime(2005, 7, 29),
+        )
+        a2.comments.create(
+            text="LMAO",
+            pub_date=datetime(2010, 7, 28),
+        )
+        a3.comments.create(
+            text="+1",
+            pub_date=datetime(2005, 8, 29),
+        )
+
+        c = Category.objects.create(name="serious-news")
+        c.articles.add(a1, a3)
+
+        self.assertQuerysetEqual(
+            Comment.objects.dates("article__pub_date", "year"), [
+                datetime(2005, 1, 1),
+                datetime(2010, 1, 1),
+            ],
+            lambda d: d,
+        )
+        self.assertQuerysetEqual(
+            Comment.objects.dates("article__pub_date", "month"), [
+                datetime(2005, 7, 1),
+                datetime(2010, 7, 1),
+            ],
+            lambda d: d
+        )
+        self.assertQuerysetEqual(
+            Comment.objects.dates("article__pub_date", "day"), [
+                datetime(2005, 7, 28),
+                datetime(2010, 7, 28),
+            ],
+            lambda d: d
+        )
+        self.assertQuerysetEqual(
+            Article.objects.dates("comments__pub_date", "day"), [
+                datetime(2005, 7, 28),
+                datetime(2005, 7, 29),
+                datetime(2005, 8, 29),
+                datetime(2010, 7, 28),
+            ],
+            lambda d: d
+        )
+        self.assertQuerysetEqual(
+            Article.objects.dates("comments__approval_date", "day"), []
+        )
+        self.assertQuerysetEqual(
+            Category.objects.dates("articles__pub_date", "day"), [
+                datetime(2005, 7, 28),
+            ],
+            lambda d: d,
+        )