SF 643115:  Set._update() had a special case for dictionaries which allowed
non-true values to leak in.  This threw-off equality testing which depends
on the underlying dictionaries having both the same keys and values.
diff --git a/Lib/test/test_sets.py b/Lib/test/test_sets.py
index 9bc3eeb..f80d58e 100644
--- a/Lib/test/test_sets.py
+++ b/Lib/test/test_sets.py
@@ -179,6 +179,9 @@
     def setUp(self):
         self.set = Set((2, 4, 6))
 
+    def test_eq(self):              # SF bug 643115
+        self.assertEqual(self.set, Set({2:1,4:3,6:5}))
+
     def test_union_subset(self):
         result = self.set | Set([2])
         self.assertEqual(result, Set((2, 4, 6)))