Index: Lib/difflib.py
===================================================================
--- Lib/difflib.py	(Revision 85136)
+++ Lib/difflib.py	(Arbeitskopie)
@@ -526,8 +526,8 @@
             non_adjacent.append((i1, j1, k1))
 
         non_adjacent.append( (la, lb, 0) )
-        self.matching_blocks = non_adjacent
-        return map(Match._make, self.matching_blocks)
+        self.matching_blocks = map(Match._make, non_adjacent)
+        return self.matching_blocks
 
     def get_opcodes(self):
         """Return list of 5-tuples describing how to turn a into b.
Index: Lib/test/test_difflib.py
===================================================================
--- Lib/test/test_difflib.py	(Revision 85136)
+++ Lib/test/test_difflib.py	(Arbeitskopie)
@@ -181,10 +181,21 @@
         self.assertEqual(list(cd)[0:2], ["*** Original", "--- Current"])
 
 
+class TestMatchingBlocks(unittest.TestCase):
+    def test_matching_blocks_deterministic(self):
+        s = difflib.SequenceMatcher(None, ['a', 'b', 'c'], ['b', 'c', 'a'])
+        ret1 = s.get_matching_blocks()
+        ret2 = s.get_matching_blocks()
+
+        self.assertEqual(ret1, ret2)
+        for match_idx in range(len(ret1)):
+	    self.assertEqual(type(ret1[match_idx]), type(ret2[match_idx]))
+
+
 def test_main():
     difflib.HtmlDiff._default_prefix = 0
     Doctests = doctest.DocTestSuite(difflib)
-    run_unittest(TestSFpatches, TestSFbugs, TestOutputFormat, Doctests)
+    run_unittest(TestSFpatches, TestSFbugs, TestOutputFormat, TestMatchingBlocks, Doctests)
 
 if __name__ == '__main__':
     test_main()