From: Neal Norwitz Date: Thu, 27 Jul 2006 04:04:50 +0000 (+0000) Subject: No functional change. Add comment and assert to describe why there cannot be overflo... X-Git-Tag: v2.5b3~142 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=37f694f21b0f5d5633516ccd8c15f4bd1822c470;p=python No functional change. Add comment and assert to describe why there cannot be overflow which was reported by Klocwork. Discussed on python-dev --- diff --git a/Modules/unicodedata.c b/Modules/unicodedata.c index 0660353a80..1b0be28fd2 100644 --- a/Modules/unicodedata.c +++ b/Modules/unicodedata.c @@ -395,6 +395,7 @@ unicodedata_decomposition(PyObject *self, PyObject *args) PyUnicodeObject *v; char decomp[256]; int code, index, count, i; + unsigned int prefix_index; if (!PyArg_ParseTuple(args, "O!:decomposition", &PyUnicode_Type, &v)) @@ -428,9 +429,15 @@ unicodedata_decomposition(PyObject *self, PyObject *args) /* XXX: could allocate the PyString up front instead (strlen(prefix) + 5 * count + 1 bytes) */ + /* Based on how index is calculated above and decomp_data is generated + from Tools/unicode/makeunicodedata.py, it should not be possible + to overflow decomp_prefix. */ + prefix_index = decomp_data[index] & 255; + assert(prefix_index < (sizeof(decomp_prefix)/sizeof(*decomp_prefix))); + /* copy prefix */ - i = strlen(decomp_prefix[decomp_data[index] & 255]); - memcpy(decomp, decomp_prefix[decomp_data[index] & 255], i); + i = strlen(decomp_prefix[prefix_index]); + memcpy(decomp, decomp_prefix[prefix_index], i); while (count-- > 0) { if (i)