2 files changed, 50 insertions, 0 deletions
diff --git a/Lib/test/_test_multiprocessing.py b/Lib/test/_test_multiprocessing.py
index b2d656ab428..6b1b1677910 100644
--- a/Lib/test/_test_multiprocessing.py
+++ b/Lib/test/_test_multiprocessing.py
@@ -247,6 +247,30 @@ class _TestProcess(BaseTestCase):
         self.assertEqual(current.ident, os.getpid())
         self.assertEqual(current.exitcode, None)
 
+    def test_args_argument(self):
+        # bpo-45735: Using list or tuple as *args* in constructor could
+        # achieve the same effect.
+        args_cases = (1, "str", [1], (1,))
+        args_types = (list, tuple)
+
+        test_cases = itertools.product(args_cases, args_types)
+
+        for args, args_type in test_cases:
+            with self.subTest(args=args, args_type=args_type):
+                q = self.Queue(1)
+                # pass a tuple or list as args
+                p = self.Process(target=self._test_args, args=args_type((q, args)))
+                p.daemon = True
+                p.start()
+                child_args = q.get()
+                self.assertEqual(child_args, args)
+                p.join()
+                close_queue(q)
+
+    @classmethod
+    def _test_args(cls, q, arg):
+        q.put(arg)
+
     def test_daemon_argument(self):
         if self.TYPE == "threads":
             self.skipTest('test not appropriate for {}'.format(self.TYPE))
diff --git a/Lib/test/test_threading.py b/Lib/test/test_threading.py
index 4830571474b..16c6934c6d4 100644
--- a/Lib/test/test_threading.py
+++ b/Lib/test/test_threading.py
@@ -123,6 +123,32 @@ class ThreadTests(BaseTestCase):
             thread = threading.Thread(target=func)
             self.assertEqual(thread.name, "Thread-5 (func)")
 
+    def test_args_argument(self):
+        # bpo-45735: Using list or tuple as *args* in constructor could
+        # achieve the same effect.
+        num_list = [1]
+        num_tuple = (1,)
+
+        str_list = ["str"]
+        str_tuple = ("str",)
+
+        list_in_tuple = ([1],)
+        tuple_in_list = [(1,)]
+
+        test_cases = (
+            (num_list, lambda arg: self.assertEqual(arg, 1)),
+            (num_tuple, lambda arg: self.assertEqual(arg, 1)),
+            (str_list, lambda arg: self.assertEqual(arg, "str")),
+            (str_tuple, lambda arg: self.assertEqual(arg, "str")),
+            (list_in_tuple, lambda arg: self.assertEqual(arg, [1])),
+            (tuple_in_list, lambda arg: self.assertEqual(arg, (1,)))
+        )
+
+        for args, target in test_cases:
+            with self.subTest(target=target, args=args):
+                t = threading.Thread(target=target, args=args)
+                t.start()
+
     @cpython_only
     def test_disallow_instantiation(self):
         # Ensure that the type disallows instantiation (bpo-43916)