bpo-40792: Make the result of PyNumber_Index() always having exact type int. (GH-20443)

Previously, the result could have been an instance of a subclass of int.

Also revert bpo-26202 and make attributes start, stop and step of the range
object having exact type int.

Add private function _PyNumber_Index() which preserves the old behavior
of PyNumber_Index() for performance to use it in the conversion functions
like PyLong_AsLong().

2 files changed, 3 insertions, 3 deletions

diff --git a/Python/clinic/_warnings.c.h b/Python/clinic/_warnings.c.h
index 80ed2ae..ad6b9a8 100644
--- a/Python/clinic/_warnings.c.h
+++ b/Python/clinic/_warnings.c.h
@@ -45,7 +45,7 @@ warnings_warn(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObjec
     if (args[2]) {
         {
             Py_ssize_t ival = -1;
-            PyObject *iobj = PyNumber_Index(args[2]);
+            PyObject *iobj = _PyNumber_Index(args[2]);
             if (iobj != NULL) {
                 ival = PyLong_AsSsize_t(iobj);
                 Py_DECREF(iobj);
@@ -66,4 +66,4 @@ skip_optional_pos:
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=484e5ffe94edf0f0 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=eb9997fa998fdbad input=a9049054013a1b77]*/
diff --git a/Python/getargs.c b/Python/getargs.c
index 63afae2..524ad91 100644
--- a/Python/getargs.c
+++ b/Python/getargs.c
@@ -784,7 +784,7 @@ convertsimple(PyObject *arg, const char **p_format, va_list *p_va, int flags,
         PyObject *iobj;
         Py_ssize_t *p = va_arg(*p_va, Py_ssize_t *);
         Py_ssize_t ival = -1;
-        iobj = PyNumber_Index(arg);
+        iobj = _PyNumber_Index(arg);
         if (iobj != NULL) {
             ival = PyLong_AsSsize_t(iobj);
             Py_DECREF(iobj);