startswith and endswith don't accept None as slice index. Patch by Torsten Becker. (closes #11828)

4 files changed, 74 insertions, 64 deletions

diff --git a/Objects/bytearrayobject.c b/Objects/bytearrayobject.c
index 8aa770d..6fc229d 100644
--- a/Objects/bytearrayobject.c
+++ b/Objects/bytearrayobject.c
@@ -1082,8 +1082,8 @@ bytearray_find_internal(PyByteArrayObject *self, PyObject *args, int dir)
     Py_ssize_t start=0, end=PY_SSIZE_T_MAX;
     Py_ssize_t res;
 
-    if (!PyArg_ParseTuple(args, "O|O&O&:find/rfind/index/rindex", &subobj,
-        _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
+    if (!stringlib_parse_args_finds("find/rfind/index/rindex",
+                                    args, &subobj, &start, &end))
         return -2;
     if (_getbuffer(subobj, &subbuf) < 0)
         return -2;
@@ -1133,8 +1133,7 @@ bytearray_count(PyByteArrayObject *self, PyObject *args)
     Py_buffer vsub;
     PyObject *count_obj;
 
-    if (!PyArg_ParseTuple(args, "O|O&O&:count", &sub_obj,
-        _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
+    if (!stringlib_parse_args_finds("count", args, &sub_obj, &start, &end))
         return NULL;
 
     if (_getbuffer(sub_obj, &vsub) < 0)
@@ -1292,8 +1291,7 @@ bytearray_startswith(PyByteArrayObject *self, PyObject *args)
     PyObject *subobj;
     int result;
 
-    if (!PyArg_ParseTuple(args, "O|O&O&:startswith", &subobj,
-        _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
+    if (!stringlib_parse_args_finds("startswith", args, &subobj, &start, &end))
         return NULL;
     if (PyTuple_Check(subobj)) {
         Py_ssize_t i;
@@ -1332,8 +1330,7 @@ bytearray_endswith(PyByteArrayObject *self, PyObject *args)
     PyObject *subobj;
     int result;
 
-    if (!PyArg_ParseTuple(args, "O|O&O&:endswith", &subobj,
-        _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
+    if (!stringlib_parse_args_finds("endswith", args, &subobj, &start, &end))
         return NULL;
     if (PyTuple_Check(subobj)) {
         Py_ssize_t i;
diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index 334e356..616f390 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -1567,19 +1567,9 @@ bytes_find_internal(PyBytesObject *self, PyObject *args, int dir)
     const char *sub;
     Py_ssize_t sub_len;
     Py_ssize_t start=0, end=PY_SSIZE_T_MAX;
-    PyObject *obj_start=Py_None, *obj_end=Py_None;
 
-    if (!PyArg_ParseTuple(args, "O|OO:find/rfind/index/rindex", &subobj,
-        &obj_start, &obj_end))
-        return -2;
-    /* To support None in "start" and "end" arguments, meaning
-       the same as if they were not passed.
-    */
-    if (obj_start != Py_None)
-        if (!_PyEval_SliceIndex(obj_start, &start))
-        return -2;
-    if (obj_end != Py_None)
-        if (!_PyEval_SliceIndex(obj_end, &end))
+    if (!stringlib_parse_args_finds("find/rfind/index/rindex",
+                                    args, &subobj, &start, &end))
         return -2;
 
     if (PyBytes_Check(subobj)) {
@@ -1826,8 +1816,7 @@ bytes_count(PyBytesObject *self, PyObject *args)
     Py_ssize_t sub_len;
     Py_ssize_t start = 0, end = PY_SSIZE_T_MAX;
 
-    if (!PyArg_ParseTuple(args, "O|O&O&:count", &sub_obj,
-        _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
+    if (!stringlib_parse_args_finds("count", args, &sub_obj, &start, &end))
         return NULL;
 
     if (PyBytes_Check(sub_obj)) {
@@ -2648,8 +2637,7 @@ bytes_startswith(PyBytesObject *self, PyObject *args)
     PyObject *subobj;
     int result;
 
-    if (!PyArg_ParseTuple(args, "O|O&O&:startswith", &subobj,
-        _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
+    if (!stringlib_parse_args_finds("startswith", args, &subobj, &start, &end))
         return NULL;
     if (PyTuple_Check(subobj)) {
         Py_ssize_t i;
@@ -2689,8 +2677,7 @@ bytes_endswith(PyBytesObject *self, PyObject *args)
     PyObject *subobj;
     int result;
 
-    if (!PyArg_ParseTuple(args, "O|O&O&:endswith", &subobj,
-        _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
+    if (!stringlib_parse_args_finds("endswith", args, &subobj, &start, &end))
         return NULL;
     if (PyTuple_Check(subobj)) {
         Py_ssize_t i;
diff --git a/Objects/stringlib/find.h b/Objects/stringlib/find.h
index bf06530..4407d71 100644
--- a/Objects/stringlib/find.h
+++ b/Objects/stringlib/find.h
@@ -102,32 +102,33 @@ stringlib_contains_obj(PyObject* str, PyObject* sub)
 
 #endif /* STRINGLIB_STR */
 
-#ifdef FROM_UNICODE
-
 /*
 This function is a helper for the "find" family (find, rfind, index,
-rindex) of unicodeobject.c file, because they all have the same 
-behaviour for the arguments.
+rindex) and for count, startswith and endswith, because they all have
+the same behaviour for the arguments.
 
 It does not touch the variables received until it knows everything 
 is ok.
-
-Note that we receive a pointer to the pointer of the substring object,
-so when we create that object in this function we don't DECREF it,
-because it continues living in the caller functions (those functions, 
-after finishing using the substring, must DECREF it).
 */
 
+#define FORMAT_BUFFER_SIZE 50
+
 Py_LOCAL_INLINE(int)
-_ParseTupleFinds (PyObject *args, PyObject **substring, 
-                  Py_ssize_t *start, Py_ssize_t *end) {
-    PyObject *tmp_substring;
+stringlib_parse_args_finds(const char * function_name, PyObject *args,
+                           PyObject **subobj,
+                           Py_ssize_t *start, Py_ssize_t *end)
+{
+    PyObject *tmp_subobj;
     Py_ssize_t tmp_start = 0;
     Py_ssize_t tmp_end = PY_SSIZE_T_MAX;
     PyObject *obj_start=Py_None, *obj_end=Py_None;
+    char format[FORMAT_BUFFER_SIZE] = "O|OO:";
+    size_t len = strlen(format);
 
-    if (!PyArg_ParseTuple(args, "O|OO:find", &tmp_substring,
-         &obj_start, &obj_end))
+    strncpy(format + len, function_name, FORMAT_BUFFER_SIZE - len - 1);
+    format[FORMAT_BUFFER_SIZE - 1] = '\0';
+
+    if (!PyArg_ParseTuple(args, format, &tmp_subobj, &obj_start, &obj_end))
         return 0;
 
     /* To support None in "start" and "end" arguments, meaning
@@ -140,16 +141,44 @@ _ParseTupleFinds (PyObject *args, PyObject **substring,
         if (!_PyEval_SliceIndex(obj_end, &tmp_end))
             return 0;
 
-    tmp_substring = PyUnicode_FromObject(tmp_substring);
-    if (!tmp_substring)
-        return 0;
-
     *start = tmp_start;
     *end = tmp_end;
-    *substring = tmp_substring;
+    *subobj = tmp_subobj;
     return 1;
 }
 
+#undef FORMAT_BUFFER_SIZE
+
+#ifdef FROM_UNICODE
+
+/*
+Wraps stringlib_parse_args_finds() and additionally ensures that the
+first argument is a unicode object.
+
+Note that we receive a pointer to the pointer of the substring object,
+so when we create that object in this function we don't DECREF it,
+because it continues living in the caller functions (those functions, 
+after finishing using the substring, must DECREF it).
+*/
+
+Py_LOCAL_INLINE(int)
+stringlib_parse_args_finds_unicode(const char * function_name, PyObject *args,
+                                   PyUnicodeObject **substring,
+                                   Py_ssize_t *start, Py_ssize_t *end)
+{
+    PyObject *tmp_substring;
+
+    if(stringlib_parse_args_finds(function_name, args, &tmp_substring,
+                                  start, end)) {
+        tmp_substring = PyUnicode_FromObject(tmp_substring);
+        if (!tmp_substring)
+            return 0;
+        *substring = (PyUnicodeObject *)tmp_substring;
+        return 1;
+    }
+    return 0;
+}
+
 #endif /* FROM_UNICODE */
 
 #endif /* STRINGLIB_FIND_H */
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 6bffaea..877640d 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -7150,13 +7150,8 @@ unicode_count(PyUnicodeObject *self, PyObject *args)
     Py_ssize_t end = PY_SSIZE_T_MAX;
     PyObject *result;
 
-    if (!PyArg_ParseTuple(args, "O|O&O&:count", &substring,
-                          _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
-        return NULL;
-
-    substring = (PyUnicodeObject *)PyUnicode_FromObject(
-        (PyObject *)substring);
-    if (substring == NULL)
+    if (!stringlib_parse_args_finds_unicode("count", args, &substring,
+                                            &start, &end))
         return NULL;
 
     FIX_START_END(self);
@@ -7306,12 +7301,13 @@ Return -1 on failure.");
 static PyObject *
 unicode_find(PyUnicodeObject *self, PyObject *args)
 {
-    PyObject *substring;
+    PyUnicodeObject *substring;
     Py_ssize_t start;
     Py_ssize_t end;
     Py_ssize_t result;
 
-    if (!_ParseTupleFinds(args, &substring, &start, &end))
+    if (!stringlib_parse_args_finds_unicode("find", args, &substring,
+                                            &start, &end))
         return NULL;
 
     result = stringlib_find_slice(
@@ -7368,11 +7364,12 @@ static PyObject *
 unicode_index(PyUnicodeObject *self, PyObject *args)
 {
     Py_ssize_t result;
-    PyObject *substring;
+    PyUnicodeObject *substring;
     Py_ssize_t start;
     Py_ssize_t end;
 
-    if (!_ParseTupleFinds(args, &substring, &start, &end))
+    if (!stringlib_parse_args_finds_unicode("index", args, &substring,
+                                            &start, &end))
         return NULL;
 
     result = stringlib_find_slice(
@@ -8230,12 +8227,13 @@ Return -1 on failure.");
 static PyObject *
 unicode_rfind(PyUnicodeObject *self, PyObject *args)
 {
-    PyObject *substring;
+    PyUnicodeObject *substring;
     Py_ssize_t start;
     Py_ssize_t end;
     Py_ssize_t result;
 
-    if (!_ParseTupleFinds(args, &substring, &start, &end))
+    if (!stringlib_parse_args_finds_unicode("rfind", args, &substring,
+                                            &start, &end))
         return NULL;
 
     result = stringlib_rfind_slice(
@@ -8257,12 +8255,13 @@ Like S.rfind() but raise ValueError when the substring is not found.");
 static PyObject *
 unicode_rindex(PyUnicodeObject *self, PyObject *args)
 {
-    PyObject *substring;
+    PyUnicodeObject *substring;
     Py_ssize_t start;
     Py_ssize_t end;
     Py_ssize_t result;
 
-    if (!_ParseTupleFinds(args, &substring, &start, &end))
+    if (!stringlib_parse_args_finds_unicode("rindex", args, &substring,
+                                            &start, &end))
         return NULL;
 
     result = stringlib_rfind_slice(
@@ -8725,8 +8724,7 @@ unicode_startswith(PyUnicodeObject *self,
     Py_ssize_t end = PY_SSIZE_T_MAX;
     int result;
 
-    if (!PyArg_ParseTuple(args, "O|O&O&:startswith", &subobj,
-                          _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
+    if (!stringlib_parse_args_finds("startswith", args, &subobj, &start, &end))
         return NULL;
     if (PyTuple_Check(subobj)) {
         Py_ssize_t i;
@@ -8771,8 +8769,7 @@ unicode_endswith(PyUnicodeObject *self,
     Py_ssize_t end = PY_SSIZE_T_MAX;
     int result;
 
-    if (!PyArg_ParseTuple(args, "O|O&O&:endswith", &subobj,
-                          _PyEval_SliceIndex, &start, _PyEval_SliceIndex, &end))
+    if (!stringlib_parse_args_finds("endswith", args, &subobj, &start, &end))
         return NULL;
     if (PyTuple_Check(subobj)) {
         Py_ssize_t i;