[3.0.x] Fixed #31109 -- Disabled grouping by aliases on QuerySet.exists().

Clearing the SELECT clause in Query.has_results was orphaning GROUP BY
references to it.

Thanks Thierry Bastian for the report and Baptiste Mispelon for the
bisect.

Regression in fb3f034f1c63160c0ff13c609acd01c18be12f80.

Backport of 720de4d0441fcfdb543051389c70efbe66ed962a from master

1 files changed, 10 insertions, 0 deletions

diff --git a/tests/aggregation/tests.py b/tests/aggregation/tests.py
index 5ba2e180e0..efc0a72c86 100644
--- a/tests/aggregation/tests.py
+++ b/tests/aggregation/tests.py
@@ -1139,6 +1139,16 @@ class AggregateTestCase(TestCase):
             list(publisher_qs)
         self.assertEqual(ctx[0]['sql'].count('SELECT'), 2)
 
+    def test_aggregation_subquery_annotation_exists(self):
+        latest_book_pubdate_qs = Book.objects.filter(
+            publisher=OuterRef('pk')
+        ).order_by('-pubdate').values('pubdate')[:1]
+        publisher_qs = Publisher.objects.annotate(
+            latest_book_pubdate=Subquery(latest_book_pubdate_qs),
+            count=Count('book'),
+        )
+        self.assertTrue(publisher_qs.exists())
+
     @skipUnlessDBFeature('supports_subqueries_in_group_by')
     def test_group_by_subquery_annotation(self):
         """