Fixes Issue 1401. When redirected, a possible POST get converted

to GET, so it loses its payload. So, it also must lose the
headers related to the payload (if it has no content any more,
it shouldn't indicate content length and type).

Lib/test/test_urllib2.py

@@ -822,6 +822,8 @@ class HandlerTests(unittest.TestCase):
                 method = getattr(h, "http_error_%s" % code)
                 req = Request(from_url, data)
                 req.add_header("Nonsense", "viking=withhold")
+                if data is not None:
+                    req.add_header("Content-Length", str(len(data)))
                 req.add_unredirected_header("Spam", "spam")
                 try:
                     method(req, MockFile(), code, "Blah",
@@ -834,6 +836,13 @@ class HandlerTests(unittest.TestCase):
                     self.assertEqual(o.req.get_method(), "GET")
                 except AttributeError:
                     self.assert_(not o.req.has_data())
+
+                # now it's a GET, there should not be headers regarding content
+                # (possibly dragged from before being a POST)
+                headers = [x.lower() for x in o.req.headers]
+                self.assertTrue("content-length" not in headers)
+                self.assertTrue("content-type" not in headers)
+
                 self.assertEqual(o.req.headers["Nonsense"],
                                  "viking=withhold")
                 self.assert_("Spam" not in o.req.headers)

Lib/urllib2.py

@@ -534,8 +534,11 @@ class HTTPRedirectHandler(BaseHandler):
             # do the same.
             # be conciliant with URIs containing a space
             newurl = newurl.replace(' ', '%20')
+            newheaders = dict((k,v) for k,v in req.headers.items()
+                              if k.lower() not in ("content-length", "content-type")
+                             )
             return Request(newurl,
-                           headers=req.headers,
+                           headers=newheaders,
                            origin_req_host=req.get_origin_req_host(),
                            unverifiable=True)
         else: