From ee4b9ce598242078500205e2c9d8564384c3fd32 Mon Sep 17 00:00:00 2001
From: Thomas Kluyver <thomas@kluyver.me.uk>
Date: Thu, 3 Nov 2016 09:43:13 -0700
Subject: [PATCH] Allow None for post_save_hook

See gh-1868
---
 notebook/services/contents/filemanager.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/notebook/services/contents/filemanager.py b/notebook/services/contents/filemanager.py
index 2b7415bc0..cd8634313 100644
--- a/notebook/services/contents/filemanager.py
+++ b/notebook/services/contents/filemanager.py
@@ -93,7 +93,7 @@ class FileContentsManager(FileManagerMixin, ContentsManager):
 
         self.post_save_hook = _post_save_script
 
-    post_save_hook = Any(None, config=True,
+    post_save_hook = Any(None, config=True, allow_none=True,
         help="""Python callable or importstring thereof
 
         to be called on the path of a file just saved.