From 26f723e4e63185b35b2f11285f50cfc3ac52b8fc Mon Sep 17 00:00:00 2001
From: Harrison Gregg <hcg28@cornell.edu>
Date: Sun, 30 Apr 2017 19:07:29 -0400
Subject: [PATCH] Allow formdata value to be None to drop field generated from
 response

---
 scrapy/http/request/form.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scrapy/http/request/form.py b/scrapy/http/request/form.py
index 905d8412f..d9d178a3e 100644
--- a/scrapy/http/request/form.py
+++ b/scrapy/http/request/form.py
@@ -135,7 +135,7 @@ def _get_inputs(form, formdata, dont_click, clickdata, response):
         if clickable and clickable[0] not in formdata and not clickable[0] is None:
             values.append(clickable)
 
-    values.extend(formdata.items())
+    values.extend((k, v) for k, v in formdata.items() if v is not None)
     return values