[3.8] bpo-40417: Fix deprecation warning in PyImport_ReloadModule (py…

…thonGH-19750)

I can add another commit with the new test case I wrote to verify that the warning was being printed before my change, stopped printing after my change, and that the function does not return null after my change.

Automerge-Triggered-By: @brettcannon.
(cherry picked from commit f40bd46)

Co-authored-by: Robert Rouhani <robert.rouhani@gmail.com>

Misc/NEWS.d/next/Core and Builtins/2020-05-01-19-04-52.bpo-40417.Sti2lJ.rst

@@ -0,0 +1 @@
+Fix imp module deprecation warning when PyImport_ReloadModule is called. Patch by Robert Rouhani.

Python/import.c

@@ -1908,23 +1908,23 @@ PyImport_ImportModuleLevel(const char *name, PyObject *globals, PyObject *locals
 PyObject *
 PyImport_ReloadModule(PyObject *m)
 {
- _Py_IDENTIFIER(imp);
+ _Py_IDENTIFIER(importlib);
  _Py_IDENTIFIER(reload);
  PyObject *reloaded_module = NULL;
- PyObject *imp = _PyImport_GetModuleId(&PyId_imp);
- if (imp == NULL) {
+ PyObject *importlib = _PyImport_GetModuleId(&PyId_importlib);
+ if (importlib == NULL) {
  if (PyErr_Occurred()) {
  return NULL;
  }
 
- imp = PyImport_ImportModule("imp");
- if (imp == NULL) {
+ importlib = PyImport_ImportModule("importlib");
+ if (importlib == NULL) {
  return NULL;
  }
  }
 
- reloaded_module = _PyObject_CallMethodIdObjArgs(imp, &PyId_reload, m, NULL);
- Py_DECREF(imp);
+ reloaded_module = _PyObject_CallMethodIdObjArgs(importlib, &PyId_reload, m, NULL);
+ Py_DECREF(importlib);
  return reloaded_module;
 }