Force zlib.crc32 and zlib.adler32 to return a signed integer on all platforms

regardless of the native sizeof(long) used in the integer object.

This somewhat odd behavior of returning a signed is maintained in 2.x for
compatibility reasons of always returning an integer rather than a long object.

Fixes Issue1202 for Python 2.6

1 files changed, 9 insertions, 0 deletions

diff --git a/Lib/test/test_zlib.py b/Lib/test/test_zlib.py
index 13926e1..7c7ef26 100644
--- a/Lib/test/test_zlib.py
+++ b/Lib/test/test_zlib.py
@@ -38,6 +38,15 @@ class ChecksumTestCase(unittest.TestCase):
         self.assertEqual(zlib.crc32("penguin"), zlib.crc32("penguin", 0))
         self.assertEqual(zlib.adler32("penguin"),zlib.adler32("penguin",1))
 
+    def test_abcdefghijklmnop(self):
+        """test issue1202 compliance: signed crc32, adler32 in 2.x"""
+        foo = 'abcdefghijklmnop'
+        # explicitly test signed behavior
+        self.assertEqual(zlib.crc32(foo), -1808088941)
+        self.assertEqual(zlib.crc32('spam'), 1138425661)
+        self.assertEqual(zlib.adler32(foo+foo), -721416943)
+        self.assertEqual(zlib.adler32('spam'), 72286642)
+
 
 
 class ExceptionTestCase(unittest.TestCase):