changeset:   80401:797de1864fd9
branch:      3.3
parent:      80398:e75945ac0bed
user:        Antoine Pitrou <solipsis@pitrou.net>
date:        Sun Nov 11 20:10:48 2012 +0100
files:       Lib/test/test_hash.py
description:
Add a test for hashing of unaligned memory buffers (from issue #16427).


diff -r e75945ac0bed -r 797de1864fd9 Lib/test/test_hash.py
--- a/Lib/test/test_hash.py	Sun Nov 11 19:40:49 2012 +0100
+++ b/Lib/test/test_hash.py	Sun Nov 11 20:10:48 2012 +0100
@@ -45,6 +45,16 @@
         self.same_hash(int(1.23e300), float(1.23e300))
         self.same_hash(float(0.5), complex(0.5, 0.0))
 
+    def test_unaligned_buffers(self):
+        # The hash function for bytes-like objects shouldn't have
+        # alignment-dependent results (example in issue #16427).
+        b = b"123456789abcdefghijklmnopqrstuvwxyz" * 128
+        for i in range(16):
+            for j in range(16):
+                aligned = b[i:128+j]
+                unaligned = memoryview(b)[i:128+j]
+                self.assertEqual(hash(aligned), hash(unaligned))
+
 
 _default_hash = object.__hash__
 class DefaultHash(object): pass