Fixed #32455 -- Allowed right combining Q() with boolean expressions.

django/db/models/query_utils.py

@@ -40,7 +40,7 @@ class Q(tree.Node):
         super().__init__(children=[*args, *sorted(kwargs.items())], connector=_connector, negated=_negated)
 
     def _combine(self, other, conn):
-        if not isinstance(other, Q):
+        if not(isinstance(other, Q) or getattr(other, 'conditional', False) is True):
             raise TypeError(other)
 
         # If the other Q() is empty, ignore it and just use `self`.

tests/expressions/tests.py

@@ -815,6 +815,14 @@ class BasicExpressionsTests(TestCase):
             Employee.objects.filter(Exists(is_poc) | Q(salary__lt=15)),
             [self.example_inc.ceo, self.max],
         )
+        self.assertCountEqual(
+            Employee.objects.filter(Q(salary__gte=30) & Exists(is_ceo)),
+            [self.max],
+        )
+        self.assertCountEqual(
+            Employee.objects.filter(Q(salary__lt=15) | Exists(is_poc)),
+            [self.example_inc.ceo, self.max],
+        )
 
     def test_boolean_expression_combined_with_empty_Q(self):
         is_poc = Company.objects.filter(point_of_contact=OuterRef('pk'))
@@ -822,7 +830,9 @@ class BasicExpressionsTests(TestCase):
         self.gmbh.save()
         tests = [
             Exists(is_poc) & Q(),
+            Q() & Exists(is_poc),
             Exists(is_poc) | Q(),
+            Q() | Exists(is_poc),
         ]
         for conditions in tests:
             with self.subTest(conditions):