Ensure Grouping._with_binary_element_type() maintains class

Fixed regression where use of the :meth:`.Operators.in_` method with a
:class:`_sql.Select` object against a non-table-bound column would produce
an ``AttributeError``, or more generally using a :class:`_sql.ScalarSelect`
that has no datatype in a binary expression would produce invalid state.

Fixes: #6181
Change-Id: I1ddea433b3603fdab8f489bff571b512a6ffc66b

1 files changed, 16 insertions, 0 deletions

diff --git a/test/sql/test_operators.py b/test/sql/test_operators.py
index f6a13f8ca..0d7f331e0 100644
--- a/test/sql/test_operators.py
+++ b/test/sql/test_operators.py
@@ -1973,6 +1973,22 @@ class InTest(fixtures.TestBase, testing.AssertsCompiledSQL):
             checkparams={"myid_1": [1, 2, 3]},
         )
 
+    def test_scalar_subquery_wo_type(self):
+        """ test for :ticket:`6181` """
+
+        m = MetaData()
+        t = Table("t", m, Column("a", Integer))
+
+        # the scalar subquery of this will have no type; coercions will
+        # want to call _with_binary_element_type(); that has to return
+        # a scalar select
+        req = select(column("scan"))
+
+        self.assert_compile(
+            select(t.c.a).where(t.c.a.in_(req)),
+            "SELECT t.a FROM t WHERE t.a IN (SELECT scan)",
+        )
+
 
 class MathOperatorTest(fixtures.TestBase, testing.AssertsCompiledSQL):
     __dialect__ = "default"