From 2727503bc9c7df0093d8920713fdb5ae4db65a98 Mon Sep 17 00:00:00 2001 From: "Gregory P. Smith" Date: Thu, 20 Mar 2008 06:20:09 +0000 Subject: crc32 always returns unsigned. cleanup the code a bit and revert r61648 with the proper fix. --- Lib/test/test_zlib.py | 4 ++-- Modules/binascii.c | 28 ++++++++-------------------- Modules/zlibmodule.c | 12 ++++++------ 3 files changed, 16 insertions(+), 28 deletions(-) diff --git a/Lib/test/test_zlib.py b/Lib/test/test_zlib.py index 9cd5434..65e633b 100644 --- a/Lib/test/test_zlib.py +++ b/Lib/test/test_zlib.py @@ -42,14 +42,14 @@ class ChecksumTestCase(unittest.TestCase): def test_crc32_adler32_unsigned(self): foo = 'abcdefghijklmnop' # explicitly test signed behavior - self.assertEqual(zlib.crc32(foo), -1808088941) + self.assertEqual(zlib.crc32(foo), 2486878355) self.assertEqual(zlib.crc32('spam'), 1138425661) self.assertEqual(zlib.adler32(foo+foo), 3573550353) self.assertEqual(zlib.adler32('spam'), 72286642) def test_same_as_binascii_crc32(self): foo = 'abcdefghijklmnop' - crc = -1808088941 + crc = 2486878355 self.assertEqual(binascii.crc32(foo), crc) self.assertEqual(zlib.crc32(foo), crc) self.assertEqual(binascii.crc32('spam'), zlib.crc32('spam')) diff --git a/Modules/binascii.c b/Modules/binascii.c index 2b4b352..e09255c 100644 --- a/Modules/binascii.c +++ b/Modules/binascii.c @@ -898,33 +898,21 @@ static PyObject * binascii_crc32(PyObject *self, PyObject *args) { /* By Jim Ahlstrom; All rights transferred to CNRI */ unsigned char *bin_data; - unsigned long crc = 0UL; /* initial value of CRC */ + unsigned int crc = 0; /* initial value of CRC */ Py_ssize_t len; - long result; + unsigned int result; - if ( !PyArg_ParseTuple(args, "s#|k:crc32", &bin_data, &len, &crc) ) + if ( !PyArg_ParseTuple(args, "s#|I:crc32", &bin_data, &len, &crc) ) return NULL; crc = ~ crc; -#if SIZEOF_LONG > 4 - /* only want the trailing 32 bits */ - crc &= 0xFFFFFFFFUL; -#endif - while (len--) - crc = crc_32_tab[(crc ^ *bin_data++) & 0xffUL] ^ (crc >> 8); + while (len--) { + crc = crc_32_tab[(crc ^ *bin_data++) & 0xff] ^ (crc >> 8); /* Note: (crc >> 8) MUST zero fill on left */ + } - result = (long)(crc ^ 0xFFFFFFFFUL); -#if SIZEOF_LONG > 4 - /* Extend the sign bit. This is one way to ensure the result is the - * same across platforms. The other way would be to return an - * unbounded unsigned long, but the evidence suggests that lots of - * code outside this treats the result as if it were a signed 4-byte - * integer. - */ - result |= -(result & (1L << 31)); -#endif - return PyLong_FromLong(result); + result = (crc ^ 0xFFFFFFFF); + return PyLong_FromUnsignedLong(result & 0xffffffff); } diff --git a/Modules/zlibmodule.c b/Modules/zlibmodule.c index 551fd3e..3426ccf 100644 --- a/Modules/zlibmodule.c +++ b/Modules/zlibmodule.c @@ -915,14 +915,14 @@ PyDoc_STRVAR(adler32__doc__, static PyObject * PyZlib_adler32(PyObject *self, PyObject *args) { - uLong adler32val = adler32(0L, Z_NULL, 0); + unsigned int adler32val = adler32(0L, Z_NULL, 0); Byte *buf; int len; - if (!PyArg_ParseTuple(args, "s#|k:adler32", &buf, &len, &adler32val)) + if (!PyArg_ParseTuple(args, "s#|I:adler32", &buf, &len, &adler32val)) return NULL; adler32val = adler32(adler32val, buf, len); - return PyLong_FromUnsignedLong(adler32val & 0xffffffff); + return PyLong_FromUnsignedLong(adler32val & 0xffffffffU); } PyDoc_STRVAR(crc32__doc__, @@ -934,13 +934,13 @@ PyDoc_STRVAR(crc32__doc__, static PyObject * PyZlib_crc32(PyObject *self, PyObject *args) { - uLong crc32val = crc32(0L, Z_NULL, 0); + unsigned int crc32val = crc32(0L, Z_NULL, 0); Byte *buf; int len; - if (!PyArg_ParseTuple(args, "s#|k:crc32", &buf, &len, &crc32val)) + if (!PyArg_ParseTuple(args, "s#|I:crc32", &buf, &len, &crc32val)) return NULL; crc32val = crc32(crc32val, buf, len); - return PyLong_FromLong(crc32val & 0xffffffff); + return PyLong_FromUnsignedLong(crc32val & 0xffffffffU); } -- cgit v0.12