[3.1.x] Fixed #31614 -- Fixed aliases ordering by OrderBy() expressions of combined queryset.

Backport of 2aac176e86204785f0f2ec4838049d8fed70870e from master

1 files changed, 17 insertions, 0 deletions

diff --git a/tests/queries/test_qs_combinators.py b/tests/queries/test_qs_combinators.py
index 1d159e1fed..bd8b0c309f 100644
--- a/tests/queries/test_qs_combinators.py
+++ b/tests/queries/test_qs_combinators.py
@@ -1,3 +1,5 @@
+import operator
+
 from django.db import DatabaseError, NotSupportedError, connection
 from django.db.models import Exists, F, IntegerField, OuterRef, Value
 from django.test import TestCase, skipIfDBFeature, skipUnlessDBFeature
@@ -115,6 +117,21 @@ class QuerySetSetOperationTests(TestCase):
         qs2 = Number.objects.filter(num__gte=2, num__lte=3)
         self.assertNumbersEqual(qs1.union(qs2).order_by(F('num').desc()), [3, 2, 1, 0])
 
+    def test_ordering_by_f_expression_and_alias(self):
+        qs1 = Number.objects.filter(num__lte=1).values(alias=F('other_num'))
+        qs2 = Number.objects.filter(num__gte=2, num__lte=3).values(alias=F('other_num'))
+        self.assertQuerysetEqual(
+            qs1.union(qs2).order_by(F('alias').desc()),
+            [10, 9, 8, 7],
+            operator.itemgetter('alias'),
+        )
+        Number.objects.create(num=-1)
+        self.assertQuerysetEqual(
+            qs1.union(qs2).order_by(F('alias').desc(nulls_last=True)),
+            [10, 9, 8, 7, None],
+            operator.itemgetter('alias'),
+        )
+
     def test_union_with_values(self):
         ReservedName.objects.create(name='a', order=2)
         qs1 = ReservedName.objects.all()