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

1 files changed, 48 insertions, 19 deletions

diff --git a/Objects/stringlib/find.h b/Objects/stringlib/find.h
index f915296c..ce615dc 100644
--- a/Objects/stringlib/find.h
+++ b/Objects/stringlib/find.h
@@ -93,32 +93,33 @@ stringlib_contains_obj(PyObject* str, PyObject* sub)
 
 #endif /* STRINGLIB_WANT_CONTAINS_OBJ */
 
-#if STRINGLIB_IS_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
@@ -131,16 +132,44 @@ _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
+
+#if STRINGLIB_IS_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 /* STRINGLIB_IS_UNICODE */
 
 #endif /* STRINGLIB_FIND_H */