[3.0.x] Fixed #31607 -- Fixed evaluated Subquery equality.

Regression in 691def10a0197d83d2d108bd9043b0916d0f09b4.

Backport of a125da6a7c79b1d4c55677d0bed6f9b1d7d77353 from master

1 files changed, 19 insertions, 0 deletions

diff --git a/tests/expressions/tests.py b/tests/expressions/tests.py
index 66e19291b2..58682afd82 100644
--- a/tests/expressions/tests.py
+++ b/tests/expressions/tests.py
@@ -512,6 +512,25 @@ class BasicExpressionsTests(TestCase):
             Employee.objects.exclude(company_point_of_contact_set=None).values('pk')
         )
 
+    def test_subquery_eq(self):
+        qs = Employee.objects.annotate(
+            is_ceo=Exists(Company.objects.filter(ceo=OuterRef('pk'))),
+            is_point_of_contact=Exists(
+                Company.objects.filter(point_of_contact=OuterRef('pk')),
+            ),
+            small_company=Exists(
+                queryset=Company.objects.filter(num_employees__lt=200),
+            ),
+        ).filter(is_ceo=True, is_point_of_contact=False, small_company=True)
+        self.assertNotEqual(
+            qs.query.annotations['is_ceo'],
+            qs.query.annotations['is_point_of_contact'],
+        )
+        self.assertNotEqual(
+            qs.query.annotations['is_ceo'],
+            qs.query.annotations['small_company'],
+        )
+
     def test_in_subquery(self):
         # This is a contrived test (and you really wouldn't write this query),
         # but it is a succinct way to test the __in=Subquery() construct.