crc32 always returns unsigned. cleanup the code a bit and revert r61648 with

the proper fix.

diff --git a/Lib/test/test_zlib.py b/Lib/test/test_zlib.py
index 9cd5434ad609b341a16037d888f2542d4f84ebed..65e633bc4768f085de069e9bba6919be92171055 100644 (file)
--- 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 2b4b352f0dfbec4bb22fd49552fe86266a8cb233..e09255c2af00a67fe75b06d7753382f3fe72e7c7 100644 (file)
--- 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 551fd3e0a76b03a8a760dab1f2a0871e75ac463a..3426ccfd12118195fe4a102ff42f0606ffa94589 100644 (file)
--- 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);
 }