From: Kenneth Reitz <me@kennethreitz.com>
Date: Mon, 20 Feb 2012 17:30:12 +0000 (-0500)
Subject: Values can be none #433
X-Git-Tag: v0.10.3~10
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4f75f1f41d1301be93b7918ffb8140314ac5105d;p=services%2Fpython-requests.git

Values can be none #433
---

diff --git a/requests/utils.py b/requests/utils.py
index adb3414..97f5860 100644
--- a/requests/utils.py
+++ b/requests/utils.py
@@ -154,6 +154,8 @@ def header_expand(headers):
         # latin-1 is the most conservative encoding used on the web. Anyone
         # who needs more can encode to a byte-string before calling
         return headers.encode("latin-1")
+    elif headers is None:
+        return headers
 
     for i, (value, params) in enumerate(headers):