Trent Mick:

Fix the string methods that implement slice-like semantics with
optional args (count, find, endswith, etc.) to properly handle
indeces outside [INT_MIN, INT_MAX]. Previously the "i" formatter
for PyArg_ParseTuple was used to get the indices. These could overflow.

This patch changes the string methods to use the "O&" formatter with
the slice_index() function from ceval.c which is used to do the same
job for Python code slices (e.g. 'abcabcabc'[0:1000000000L]). slice_index()
is renamed _PyEval_SliceIndex() and is now exported. As well, the return
values for success/fail were changed to make slice_index directly
usable as required by the "O&" formatter.

[GvR: shouldn't a similar patch be applied to unicodeobject.c?]

diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index c94ee88d4be9c8e0d20c2ffbb5757bb15bb21a6f..f17fbf1a062ec69f3d9590c461a6ad0293546e29 100644 (file)
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -822,8 +822,8 @@ string_find_internal(self, args, dir)
        int n, i = 0, last = INT_MAX;
        PyObject *subobj;
 
-       if (!PyArg_ParseTuple(args, "O|ii:find/rfind/index/rindex", 
-                             &subobj, &i, &last))
+       if (!PyArg_ParseTuple(args, "O|O&O&:find/rfind/index/rindex", 
+               &subobj, _PyEval_SliceIndex, &i, _PyEval_SliceIndex, &last))
                return -2;
        if (PyString_Check(subobj)) {
                sub = PyString_AS_STRING(subobj);
@@ -1194,8 +1194,10 @@ string_count(self, args)
        int m, r;
        PyObject *subobj;
 
-       if (!PyArg_ParseTuple(args, "O|ii:count", &subobj, &i, &last))
+       if (!PyArg_ParseTuple(args, "O|O&O&:count", &subobj,
+               _PyEval_SliceIndex, &i, _PyEval_SliceIndex, &last))
                return NULL;
+
        if (PyString_Check(subobj)) {
                sub = PyString_AS_STRING(subobj);
                n = PyString_GET_SIZE(subobj);
@@ -1617,7 +1619,8 @@ string_startswith(self, args)
        int end = -1;
        PyObject *subobj;
 
-       if (!PyArg_ParseTuple(args, "O|ii:startswith", &subobj, &start, &end))
+       if (!PyArg_ParseTuple(args, "O|O&O&:startswith", &subobj,
+               _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
                return NULL;
        if (PyString_Check(subobj)) {
                prefix = PyString_AS_STRING(subobj);
@@ -1671,7 +1674,8 @@ string_endswith(self, args)
        int lower, upper;
        PyObject *subobj;
 
-       if (!PyArg_ParseTuple(args, "O|ii:endswith", &subobj, &start, &end))
+       if (!PyArg_ParseTuple(args, "O|O&O&:endswith", &subobj,
+               _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
                return NULL;
        if (PyString_Check(subobj)) {
                suffix = PyString_AS_STRING(subobj);