Fixed #17429 -- Ensured that `Meta.ordering=None` works the same if it were an…

Fixed #17429 -- Ensured that `Meta.ordering=None` works the same if it were an empty list. Thanks to self[at]dicos[dot]ru for the report and to bigkevmcd for the patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@17334 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/sql/compiler.py

@@ -347,7 +347,9 @@ class SQLCompiler(object):
         elif not self.query.default_ordering:
             ordering = self.query.order_by
         else:
-            ordering = self.query.order_by or self.query.model._meta.ordering
+            ordering = (self.query.order_by
+                        or self.query.model._meta.ordering
+                        or [])
         qn = self.quote_name_unless_alias
         qn2 = self.connection.ops.quote_name
         distinct = self.query.distinct

tests/regressiontests/queries/tests.py

@@ -830,6 +830,17 @@ class Queries1Tests(BaseQuerysetTest):
             1
         )
 
+    def test_ticket17429(self):
+        """
+        Ensure that Meta.ordering=None works the same as Meta.ordering=[]
+        """
+        original_ordering = Tag._meta.ordering
+        Tag._meta.ordering = None
+        self.assertQuerysetEqual(
+            Tag.objects.all(),
+            ['<Tag: t1>', '<Tag: t2>', '<Tag: t3>', '<Tag: t4>', '<Tag: t5>'],
+        )
+        Tag._meta.ordering = original_ordering
 
 class Queries2Tests(TestCase):
     def setUp(self):