From d874b8fe39c5aa5078556806183aa5b6c4f1cde2 Mon Sep 17 00:00:00 2001
From: Benjamin Peterson <benjamin@python.org>
Date: Wed, 1 Mar 2017 23:36:01 -0800
Subject: [PATCH] fix subprocess on Windows

---
 Lib/subprocess.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Lib/subprocess.py b/Lib/subprocess.py
index 23e9bd328c1281..76c340c87970aa 100644
--- a/Lib/subprocess.py
+++ b/Lib/subprocess.py
@@ -988,7 +988,7 @@ def _execute_child(self, args, executable, preexec_fn, close_fds,
                                          int(not close_fds),
                                          creationflags,
                                          env,
-                                         os.fspath(cwd),
+                                         os.fspath(cwd) if cwd is not None else None,
                                          startupinfo)
             finally:
                 # Child is launched. Close the parent's copy of those pipe