Add test for pickling new-style class with custom metaclass.

Lib/test/pickletester.py

@@ -24,6 +24,12 @@ class initarg(C):
     def __getinitargs__(self):
         return self.a, self.b
 
+class metaclass(type):
+    pass
+
+class use_metaclass(object):
+    __metaclass__ = metaclass
+
 # break into multiple strings to avoid confusing font-lock-mode
 DATA = """(lp1
 I0
@@ -236,6 +242,12 @@ class AbstractPickleTests(unittest.TestCase):
     def test_getinitargs(self):
         pass
 
+    def test_metaclass(self):
+        a = use_metaclass()
+        s = self.dumps(a)
+        b = self.loads(s)
+        self.assertEqual(a.__class__, b.__class__)
+
 class AbstractPickleModuleTests(unittest.TestCase):
 
     def test_dump_closed_file(self):