1 files changed, 31 insertions, 2 deletions
diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
index de13f22..e6c17a2 100644
--- a/Lib/test/test_sys.py
+++ b/Lib/test/test_sys.py
@@ -1,9 +1,12 @@
 # -*- coding: iso-8859-1 -*-
 import unittest, test.test_support
 from test.script_helper import assert_python_ok, assert_python_failure
-import sys, os, cStringIO
-import struct
+import cStringIO
+import gc
 import operator
+import os
+import struct
+import sys
 
 class SysModuleTest(unittest.TestCase):
 
@@ -754,6 +757,32 @@ class SizeofTest(unittest.TestCase):
         check(xrange(1), size('3l'))
         check(xrange(66000), size('3l'))
 
+    def check_slots(self, obj, base, extra):
+        expected = sys.getsizeof(base) + struct.calcsize(extra)
+        if gc.is_tracked(obj) and not gc.is_tracked(base):
+            expected += struct.calcsize('3P')  # PyGC_Head
+        self.assertEqual(sys.getsizeof(obj), expected)
+
+    def test_slots(self):
+        # check all subclassable types defined in Objects/ that allow
+        # non-empty __slots__
+        check = self.check_slots
+        class BA(bytearray):
+            __slots__ = 'a', 'b', 'c'
+        check(BA(), bytearray(), '3P')
+        class D(dict):
+            __slots__ = 'a', 'b', 'c'
+        check(D(x=[]), {'x': []}, '3P')
+        class L(list):
+            __slots__ = 'a', 'b', 'c'
+        check(L(), [], '3P')
+        class S(set):
+            __slots__ = 'a', 'b', 'c'
+        check(S(), set(), '3P')
+        class FS(frozenset):
+            __slots__ = 'a', 'b', 'c'
+        check(FS(), frozenset(), '3P')
+
     def test_pythontypes(self):
         # check all types defined in Python/
         size = test.test_support.calcobjsize