From 551d9f11e571eac495674f1c23cfd0dfa8af2cb7 Mon Sep 17 00:00:00 2001
From: Maximilian Hils <git@maximilianhils.com>
Date: Fri, 18 Sep 2015 18:05:50 +0200
Subject: [PATCH] experimental: don't interfere with headers

---
 netlib/http/http1/assemble.py    | 20 +++++---------------
 netlib/http/models.py            | 21 ++++-----------------
 test/http/http1/test_assemble.py | 11 +----------
 test/http/test_models.py         | 11 +++++++----
 4 files changed, 17 insertions(+), 46 deletions(-)

diff --git a/netlib/http/http1/assemble.py b/netlib/http/http1/assemble.py
index b65a6be03..c2b60a0ff 100644
--- a/netlib/http/http1/assemble.py
+++ b/netlib/http/http1/assemble.py
@@ -10,7 +10,8 @@ def assemble_request(request):
     if request.body == CONTENT_MISSING:
         raise HttpException("Cannot assemble flow with CONTENT_MISSING")
     head = assemble_request_head(request)
-    return head + request.body
+    body = b"".join(assemble_body(request.headers, [request.body]))
+    return head + body
 
 
 def assemble_request_head(request):
@@ -23,7 +24,8 @@ def assemble_response(response):
     if response.body == CONTENT_MISSING:
         raise HttpException("Cannot assemble flow with CONTENT_MISSING")
     head = assemble_response_head(response)
-    return head + response.body
+    body = b"".join(assemble_body(response.headers, [response.body]))
+    return head + body
 
 
 def assemble_response_head(response):
@@ -74,20 +76,12 @@ def _assemble_request_line(request, form=None):
 
 def _assemble_request_headers(request):
     headers = request.headers.copy()
-    for k in request._headers_to_strip_off:
-        headers.pop(k, None)
     if b"host" not in headers and request.scheme and request.host and request.port:
         headers[b"Host"] = utils.hostport(
             request.scheme,
             request.host,
             request.port
         )
-
-    # If content is defined (i.e. not None or CONTENT_MISSING), we always
-    # add a content-length header.
-    if request.body or request.body == b"":
-        headers[b"Content-Length"] = str(len(request.body)).encode("ascii")
-
     return bytes(headers)
 
 
@@ -100,8 +94,4 @@ def _assemble_response_line(response):
 
 
 def _assemble_response_headers(response):
-    headers = response.headers.copy()
-    for k in response._headers_to_strip_off:
-        headers.pop(k, None)
-
-    return bytes(headers)
+    return bytes(response.headers)
diff --git a/netlib/http/models.py b/netlib/http/models.py
index bc681de39..ff854b135 100644
--- a/netlib/http/models.py
+++ b/netlib/http/models.py
@@ -92,7 +92,10 @@ class Headers(MutableMapping, object):
         self.update(headers)
 
     def __bytes__(self):
-        return b"\r\n".join(b": ".join(field) for field in self.fields) + b"\r\n"
+        if self.fields:
+            return b"\r\n".join(b": ".join(field) for field in self.fields) + b"\r\n"
+        else:
+            return b""
 
     if six.PY2:
         __str__ = __bytes__
@@ -224,16 +227,6 @@ class Message(object):
 
 
 class Request(Message):
-    # This list is adopted legacy code.
-    # We probably don't need to strip off keep-alive.
-    _headers_to_strip_off = [
-        'Proxy-Connection',
-        'Keep-Alive',
-        'Connection',
-        'Transfer-Encoding',
-        'Upgrade',
-    ]
-
     def __init__(
             self,
             form_in,
@@ -467,12 +460,6 @@ class Request(Message):
 
 
 class Response(Message):
-    _headers_to_strip_off = [
-        'Proxy-Connection',
-        'Alternate-Protocol',
-        'Alt-Svc',
-    ]
-
     def __init__(
             self,
             http_version,
diff --git a/test/http/http1/test_assemble.py b/test/http/http1/test_assemble.py
index cdc8bda90..2d250909f 100644
--- a/test/http/http1/test_assemble.py
+++ b/test/http/http1/test_assemble.py
@@ -79,15 +79,10 @@ def test_assemble_request_headers():
     r = treq(body=b"")
     r.headers[b"Transfer-Encoding"] = b"chunked"
     c = _assemble_request_headers(r)
-    assert b"Content-Length" in c
-    assert b"Transfer-Encoding" not in c
+    assert b"Transfer-Encoding" in c
 
     assert b"Host" in _assemble_request_headers(treq(headers=Headers()))
 
-    assert b"Proxy-Connection" not in _assemble_request_headers(
-        treq(headers=Headers(Proxy_Connection="42"))
-    )
-
 
 def test_assemble_response_headers():
     # https://github.com/mitmproxy/mitmproxy/issues/186
@@ -95,7 +90,3 @@ def test_assemble_response_headers():
     r.headers["Transfer-Encoding"] = b"chunked"
     c = _assemble_response_headers(r)
     assert b"Transfer-Encoding" in c
-
-    assert b"Proxy-Connection" not in _assemble_response_headers(
-        tresp(headers=Headers(Proxy_Connection=b"42"))
-    )
diff --git a/test/http/test_models.py b/test/http/test_models.py
index c3ab4d0fc..6970a6e42 100644
--- a/test/http/test_models.py
+++ b/test/http/test_models.py
@@ -442,13 +442,16 @@ class TestHeaders(object):
 
     def test_str(self):
         headers = Headers(Host="example.com")
-        assert bytes(headers) == "Host: example.com\r\n"
+        assert bytes(headers) == b"Host: example.com\r\n"
 
         headers = Headers([
-            ["Host", "example.com"],
-            ["Accept", "text/plain"]
+            [b"Host", b"example.com"],
+            [b"Accept", b"text/plain"]
         ])
-        assert str(headers) == "Host: example.com\r\nAccept: text/plain\r\n"
+        assert bytes(headers) == b"Host: example.com\r\nAccept: text/plain\r\n"
+
+        headers = Headers()
+        assert bytes(headers) == b""
 
     def test_setitem(self):
         headers = Headers()