bpo-36763: _PyInitError always use int for exitcode (GH-13360)

We cannot use "unsigned int" for exitcode on Windows, since
Py_Main() and _Py_RunMain() always return an "int".

Changes:

* _PyPathConfig_ComputeSysPath0() now returns -1 if an exception is
  raised.
* pymain_run_python() no longer uses _PyInitError but display the
  exception and set exitcode to 1 in case of error.
* Fix _Py_RunMain(): return an exitcode rather than calling
  exit() on pymain_run_python() failure.
* _Py_ExitInitError() no longer uses ExitProcess() on Windows, use
  exit() on all platforms.
* _Py_ExitInitError() now fails with a fatal error if 'err' is not an
  error not an exit.

1 files changed, 4 insertions, 7 deletions

diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index 4e74e0b..a173eb3 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -2124,18 +2124,15 @@ Py_FatalError(const char *msg)
 void _Py_NO_RETURN
 _Py_ExitInitError(_PyInitError err)
 {
-    assert(_Py_INIT_FAILED(err));
     if (_Py_INIT_IS_EXIT(err)) {
-#ifdef MS_WINDOWS
-        ExitProcess(err.exitcode);
-#else
         exit(err.exitcode);
-#endif
     }
-    else {
-        assert(_Py_INIT_IS_ERROR(err));
+    else if (_Py_INIT_IS_ERROR(err)) {
         fatal_error(err._func, err.err_msg, 1);
     }
+    else {
+        Py_FatalError("_Py_ExitInitError() must not be called on success");
+    }
 }
 
 /* Clean up and exit */