From 22e75c1691e67a487d90166c37f3cf08531226ac Mon Sep 17 00:00:00 2001
From: Ivan Pogrebkov <chezhik@gmail.com>
Date: Fri, 26 Jan 2018 10:55:44 +0300
Subject: [PATCH] Insert null values fix

https://stackoverflow.com/questions/42601950/how-to-store-a-null-value-in-mongodb-via-mongoengine
---
 mongoengine/base/document.py | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/mongoengine/base/document.py b/mongoengine/base/document.py
index 658d0c79..956e9b0e 100644
--- a/mongoengine/base/document.py
+++ b/mongoengine/base/document.py
@@ -337,11 +337,10 @@ class BaseDocument(object):
                 value = field.generate()
                 self._data[field_name] = value
 
-            if value is not None:
-                if use_db_field:
-                    data[field.db_field] = value
-                else:
-                    data[field.name] = value
+            if use_db_field:
+                data[field.db_field] = value
+            else:
+                data[field.name] = value
 
         # Only add _cls if allow_inheritance is True
         if not self._meta.get('allow_inheritance'):