bpo-42008: Fix internal _random.Random() seeding for the one argument case (GH-22668)

diff --git a/Lib/test/test_random.py b/Lib/test/test_random.py
index 327bfa3..e7f911d 100644
--- a/Lib/test/test_random.py
+++ b/Lib/test/test_random.py
@@ -414,6 +414,15 @@ def test_bug_41052(self):
             r = _random.Random()
             self.assertRaises(TypeError, pickle.dumps, r, proto)
 
+    @test.support.cpython_only
+    def test_bug_42008(self):
+        # _random.Random should call seed with first element of arg tuple
+        import _random
+        r1 = _random.Random()
+        r1.seed(8675309)
+        r2 = _random.Random(8675309)
+        self.assertEqual(r1.random(), r2.random())
+
     def test_bug_1727780(self):
         # verify that version-2-pickles can be loaded
         # fine, whether they are created on 32-bit or 64-bit