Fixed #22550 -- Prohibited QuerySet.last()/reverse() after slicing.

2 files changed, 9 insertions, 1 deletions

diff --git a/tests/ordering/tests.py b/tests/ordering/tests.py
index de49626cf4..ff749331b9 100644
--- a/tests/ordering/tests.py
+++ b/tests/ordering/tests.py
@@ -203,6 +203,14 @@ class OrderingTests(TestCase):
             attrgetter("headline")
         )
 
+    def test_no_reordering_after_slicing(self):
+        msg = 'Cannot reverse a query once a slice has been taken.'
+        qs = Article.objects.all()[0:2]
+        with self.assertRaisesMessage(TypeError, msg):
+            qs.reverse()
+        with self.assertRaisesMessage(TypeError, msg):
+            qs.last()
+
     def test_extra_ordering(self):
         """
         Ordering can be based on fields included from an 'extra' clause
diff --git a/tests/queries/tests.py b/tests/queries/tests.py
index b69ea84345..b2d5ef5e95 100644
--- a/tests/queries/tests.py
+++ b/tests/queries/tests.py
@@ -731,10 +731,10 @@ class Queries1Tests(TestCase):
                 q.extra(select={'foo': "1"}),
                 []
             )
+            self.assertQuerysetEqual(q.reverse(), [])
             q.query.low_mark = 1
             with self.assertRaisesMessage(AssertionError, 'Cannot change a query once a slice has been taken'):
                 q.extra(select={'foo': "1"})
-            self.assertQuerysetEqual(q.reverse(), [])
             self.assertQuerysetEqual(q.defer('meal'), [])
             self.assertQuerysetEqual(q.only('meal'), [])