gh-120298: Fix use-after-free in list_richcompare_impl

Lib/test/test_bisect.py

@@ -291,16 +291,6 @@ def __gt__(self, other):
         self.assertEqual(i1, 40)
         self.assertEqual(i2, 41)
 
-    def test_use_after_free_gh120298(self):
-        class evil(object):
-            def __lt__(self, other):
-                other.clear()
-                return NotImplemented
-
-        a = [[evil()]]
-        with self.assertRaises(TypeError):
-            self.module.insort_left(a, a)
-
 class TestBisectPython(TestBisect, unittest.TestCase):
     module = py_bisect
 

Lib/test/test_deque.py

@@ -782,18 +782,6 @@ def test_runtime_error_on_empty_deque(self):
         d.append(10)
         self.assertRaises(RuntimeError, next, it)
 
-    def test_use_after_free_gh120298(self):
-        class evil(object):
-            def __lt__(self, other):
-                other.pop()
-                return NotImplemented
-
-        a = [[[evil()]]]
-        b = deque(a[0])
-        c = deque(a)
-        with self.assertRaises(TypeError):
-            b < c
-
 class Deque(deque):
     pass
 

Lib/test/test_list.py

@@ -234,6 +234,17 @@ def __eq__(self, other):
         list4 = [1]
         self.assertFalse(list3 == list4)
 
+    def test_lt_operator_modifying_operand(self):
+        # See gh-120298
+        class evil(object):
+            def __lt__(self, other):
+                other.clear()
+                return NotImplemented
+
+        a = [[evil()]]
+        with self.assertRaises(TypeError):
+            a[0] < a
+
     @cpython_only
     def test_preallocation(self):
         iterable = [0] * 10