From e50c61bc866ff4358e6ef320b4f1f31b979bd45e 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] removing Content-Type and Transfer-Encoding headers on
 redirect

---
 requests/sessions.py   |  7 ++++---
 tests/test_requests.py | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/requests/sessions.py b/requests/sessions.py
index 8d8d9105..bcbcc880 100644
--- a/requests/sessions.py
+++ b/requests/sessions.py
@@ -140,9 +140,10 @@ class SessionRedirectMixin(object):
 
             # 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:
+                    prepared_request.headers.pop(header, None)
                 prepared_request.body = None
 
             headers = prepared_request.headers
diff --git a/tests/test_requests.py b/tests/test_requests.py
index efbc7ed0..3f791334 100755
--- a/tests/test_requests.py
+++ b/tests/test_requests.py
@@ -221,6 +221,41 @@ class TestRequests:
         assert r.history[0].status_code == 303
         assert r.history[0].is_redirect
 
+    def test_header_and_body_removal_on_redirect(self, httpbin):
+        purged_headers = ('Content-Length', 'Content-Type')
+        ses = requests.Session()
+        req = requests.Request('POST', httpbin('post'), data={'test': '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 is None
+        for header in purged_headers:
+            assert header not in next_resp.request.headers
+
+    def test_transfer_enc_removal_on_redirect(self, httpbin):
+        purged_headers = ('Transfer-Encoding', 'Content-Type')
+        ses = requests.Session()
+        req = requests.Request('POST', httpbin('post'), data=(b'x' for x in range(1)))
+        prep = ses.prepare_request(req)
+        assert 'Transfer-Encoding' in prep.headers
+        resp = ses.send(prep)
+
+        # Mimic a redirect response
+        resp.status_code = 302
+        resp.headers['location'] = 'get'
+
+        # Run request through resolve_redirect
+        next_resp = next(ses.resolve_redirects(resp, prep))
+        assert next_resp.request.body is 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'}