Author: neal.norwitz Date: Tue Aug 22 00:21:19 2006 New Revision: 51450 Modified: python/trunk/Lib/test/test_unicode.py python/trunk/Misc/ACKS python/trunk/Objects/unicodeobject.c Log: Patch #1541585: fix buffer overrun when performing repr() on a unicode string in a build with wide unicode (UCS-4) support. This code could be improved, so add an XXX comment. Modified: python/trunk/Lib/test/test_unicode.py ============================================================================== --- python/trunk/Lib/test/test_unicode.py (original) +++ python/trunk/Lib/test/test_unicode.py Tue Aug 22 00:21:19 2006 @@ -92,6 +92,10 @@ "\\xfe\\xff'") testrepr = repr(u''.join(map(unichr, xrange(256)))) self.assertEqual(testrepr, latin1repr) + # Test repr works on wide unicode escapes without overflow. + self.assertEqual(repr(u"\U00010000" * 39 + u"\uffff" * 4096), + repr(u"\U00010000" * 39 + u"\uffff" * 4096)) + def test_count(self): string_tests.CommonTest.test_count(self) Modified: python/trunk/Misc/ACKS ============================================================================== --- python/trunk/Misc/ACKS (original) +++ python/trunk/Misc/ACKS Tue Aug 22 00:21:19 2006 @@ -365,6 +365,7 @@ Soren Larsen Piers Lauder Ben Laurie +Simon Law Chris Lawrence Christopher Lee Inyeol Lee Modified: python/trunk/Objects/unicodeobject.c ============================================================================== --- python/trunk/Objects/unicodeobject.c (original) +++ python/trunk/Objects/unicodeobject.c Tue Aug 22 00:21:19 2006 @@ -2040,7 +2040,32 @@ static const char *hexdigit = "0123456789abcdef"; - repr = PyString_FromStringAndSize(NULL, 2 + 6*size + 1); + /* XXX(nnorwitz): rather than over-allocating, it would be + better to choose a different scheme. Perhaps scan the + first N-chars of the string and allocate based on that size. + */ + /* Initial allocation is based on the longest-possible unichr + escape. + + In wide (UTF-32) builds '\U00xxxxxx' is 10 chars per source + unichr, so in this case it's the longest unichr escape. In + narrow (UTF-16) builds this is five chars per source unichr + since there are two unichrs in the surrogate pair, so in narrow + (UTF-16) builds it's not the longest unichr escape. + + In wide or narrow builds '\uxxxx' is 6 chars per source unichr, + so in the narrow (UTF-16) build case it's the longest unichr + escape. + */ + + repr = PyString_FromStringAndSize(NULL, + 2 +#ifdef Py_UNICODE_WIDE + + 10*size +#else + + 6*size +#endif + + 1); if (repr == NULL) return NULL; @@ -2065,15 +2090,6 @@ #ifdef Py_UNICODE_WIDE /* Map 21-bit characters to '\U00xxxxxx' */ else if (ch >= 0x10000) { - Py_ssize_t offset = p - PyString_AS_STRING(repr); - - /* Resize the string if necessary */ - if (offset + 12 > PyString_GET_SIZE(repr)) { - if (_PyString_Resize(&repr, PyString_GET_SIZE(repr) + 100)) - return NULL; - p = PyString_AS_STRING(repr) + offset; - } - *p++ = '\\'; *p++ = 'U'; *p++ = hexdigit[(ch >> 28) & 0x0000000F]; @@ -2086,8 +2102,8 @@ *p++ = hexdigit[ch & 0x0000000F]; continue; } -#endif - /* Map UTF-16 surrogate pairs to Unicode \UXXXXXXXX escapes */ +#else + /* Map UTF-16 surrogate pairs to '\U00xxxxxx' */ else if (ch >= 0xD800 && ch < 0xDC00) { Py_UNICODE ch2; Py_UCS4 ucs; @@ -2112,6 +2128,7 @@ s--; size++; } +#endif /* Map 16-bit characters to '\uxxxx' */ if (ch >= 256) {