From 88440960f9f430581ba5766aee1f0712ac96cb54 Mon Sep 17 00:00:00 2001 From: "Gregory P. Smith" Date: Tue, 25 Mar 2008 06:12:45 +0000 Subject: [PATCH] A stab in the dark attempt to fix the alpha/tru64 buildbot problem and add more test coverage of valid inputs to zlib.crc32. --- Lib/tarfile.py | 4 ++-- Lib/test/test_zlib.py | 9 +++++++++ 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/Lib/tarfile.py b/Lib/tarfile.py index 92fdb7b9d95..4991ae1b60d 100644 --- a/Lib/tarfile.py +++ b/Lib/tarfile.py @@ -420,7 +420,7 @@ class _Stream: except ImportError: raise CompressionError("zlib module is not available") self.zlib = zlib - self.crc = zlib.crc32("") + self.crc = zlib.crc32("") & 0xffffffffL if mode == "r": self._init_read_gz() else: @@ -458,7 +458,7 @@ class _Stream: """Write string s to the stream. """ if self.comptype == "gz": - self.crc = self.zlib.crc32(s, self.crc) + self.crc = self.zlib.crc32(s, self.crc) & 0xffffffffL self.pos += len(s) if self.comptype != "tar": s = self.cmp.compress(s) diff --git a/Lib/test/test_zlib.py b/Lib/test/test_zlib.py index 9f0fe18c074..0c96842c77a 100644 --- a/Lib/test/test_zlib.py +++ b/Lib/test/test_zlib.py @@ -53,6 +53,15 @@ class ChecksumTestCase(unittest.TestCase): self.assertEqual(binascii.crc32(foo), zlib.crc32(foo)) self.assertEqual(binascii.crc32('spam'), zlib.crc32('spam')) + def test_negative_crc_iv_input(self): + # The range of valid input values for the crc state should be + # -2**31 through 2**32-1 to allow inputs artifically constrained + # to a signed 32-bit integer. + self.assertEqual(zlib.crc32('ham', -1), zlib.crc32('ham', 0xffffffffL)) + self.assertEqual(zlib.crc32('spam', -3141593), + zlib.crc32('spam', 0xffd01027L)) + self.assertEqual(zlib.crc32('spam', -(2**31)), + zlib.crc32('spam', (2**31))) class ExceptionTestCase(unittest.TestCase):