From 20a2b5ac71f1d6ce674ca2633172ef5964ec9c38 Mon Sep 17 00:00:00 2001
From: Nate Prewitt <Nate.Prewitt@gmail.com>
Date: Wed, 10 Aug 2016 11:02:26 -0600
Subject: [PATCH] #3490 removing Content-Type and Transfer-Encoding headers on
 redirect

---
 requests/sessions.py   |  7 +++++--
 tests/test_requests.py | 18 ++++++++++++++++++
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/requests/sessions.py b/requests/sessions.py
index 8d8d9105b8..eafdb0b810 100644
--- a/requests/sessions.py
+++ b/requests/sessions.py
@@ -140,8 +140,11 @@ def resolve_redirects(self, resp, req, stream=False, timeout=None,
 
             # https://github.com/kennethreitz/requests/issues/1084
             if resp.status_code not in (codes.temporary_redirect, codes.permanent_redirect):
-                if 'Content-Length' in prepared_request.headers:
-                    del prepared_request.headers['Content-Length']
+                # https://github.com/kennethreitz/requests/issues/3490
+                purged_headers = ('Content-Length', 'Content-Type', 'Transfer-Encoding')
+                for header in purged_headers:
+                    if header in prepared_request.headers:
+                        del prepared_request.headers[header]
 
                 prepared_request.body = None
 
diff --git a/tests/test_requests.py b/tests/test_requests.py
index efbc7ed0bd..d1ddf393e8 100755
--- a/tests/test_requests.py
+++ b/tests/test_requests.py
@@ -221,6 +221,24 @@ def test_http_303_doesnt_change_head_to_get(self, httpbin):
         assert r.history[0].status_code == 303
         assert r.history[0].is_redirect
 
+    def test_header_removal_on_redirect(self, httpbin):
+        purged_headers = ('Content-Length', 'Content-Type', 'Transfer-Encoding')
+        data = {'test': 'data'}
+        ses = requests.Session()
+        req = requests.Request('POST', httpbin('post'), data=data)
+        prep = ses.prepare_request(req)
+        resp = ses.send(prep)
+
+        # Mimic a redirect response
+        resp.status_code = 302
+        resp.headers['location'] = 'get'
+
+        # Run request through resolve_redirects
+        next_resp = next(ses.resolve_redirects(resp, prep))
+        assert next_resp.request.body == None
+        for header in purged_headers:
+            assert header not in next_resp.request.headers
+
     def test_HTTP_200_OK_GET_WITH_PARAMS(self, httpbin):
         heads = {'User-agent': 'Mozilla/5.0'}