Remove Connection and Transfer-Encoding headers from WSGI responses.

CHANGES.rst

@@ -11,6 +11,9 @@ https://zope.readthedocs.io/en/2.13/CHANGES.html
 Bugs Fixed
 ++++++++++
 
+- Remove `Connection` and `Transfer-Encoding` headers from WSGI responses.
+  According to PEP 333 WSGI applications must not emit hop-by-hop headers.
+
 - Removed docstrings from some methods to avoid publishing them.  From
   Products.PloneHotfix20160419.  [maurits]
 

src/ZPublisher/WSGIPublisher.py

@@ -34,28 +34,24 @@
 from ZPublisher.pubevents import PubStart, PubBeforeCommit, PubAfterTraversal
 from ZPublisher.Iterators import IUnboundStreamIterator, IStreamIterator
 
-_NOW = None     # overwrite for testing
+_NOW = None  # overwrite for testing
+
+
 def _now():
     if _NOW is not None:
         return _NOW
     return time.time()
 
+
 class WSGIResponse(HTTPResponse):
     """A response object for WSGI
 
     This Response object knows nothing about ZServer, but tries to be
     compatible with the ZServerHTTPResponse.
-
-    Most significantly, streaming is not (yet) supported.
     """
-    _streaming = _chunking = 0
+    _streaming = 0
     _http_version = None
     _server_version = None
-    _http_connection = None
-
-    # Set this value to 1 if streaming output in
-    # HTTP/1.1 should use chunked encoding
-    http_chunk = 0
 
     # Append any "cleanup" functions to this list.
     after_list = ()
@@ -68,8 +64,8 @@ def finalize(self):
         # set 204 (no content) status if 200 and response is empty
         # and not streaming
         if ('content-type' not in headers and
-            'content-length' not in headers and
-            not self._streaming and self.status == 200):
+                'content-length' not in headers and
+                not self._streaming and self.status == 200):
             self.setStatus('nocontent')
 
         # add content length if not streaming
@@ -78,25 +74,6 @@ def finalize(self):
         if content_length is None and not self._streaming:
             self.setHeader('content-length', len(body))
 
-        if self._http_version == '1.0':
-            if (self._http_connection == 'keep-alive' and
-                'content-length' in self.headers):
-                self.setHeader('Connection', 'Keep-Alive')
-            else:
-                self.setHeader('Connection', 'close')
-
-        # Close the connection if we have been asked to.
-        # Use chunking if streaming output.
-        if self._http_version == '1.1':
-            if self._http_connection == 'close':
-                self.setHeader('Connection', 'close')
-            elif not self.headers.has_key('content-length'):
-                if self.http_chunk and self._streaming:
-                    self.setHeader('Transfer-Encoding', 'chunked')
-                    self._chunking = 1
-                else:
-                    self.setHeader('Connection','close')
-
         return '%s %s' % (self.status, self.errmsg), self.listHeaders()
 
     def listHeaders(self):
@@ -114,17 +91,15 @@ def _unauthorized(self):
         if realm:
             self.setHeader('WWW-Authenticate', 'basic realm="%s"' % realm, 1)
 
-    def write(self,data):
+    def write(self, data):
         """ Add data to our output stream.
 
         HTML data may be returned using a stream-oriented interface.
         This allows the browser to display partial results while
         computation of a response to proceed.
         """
         if not self._streaming:
-
             notify(PubBeforeStreaming(self))
-
             self._streaming = 1
             self.stdout.flush()
 
@@ -148,14 +123,6 @@ def setBody(self, body, title='', is_error=0):
             HTTPResponse.setBody(self, body, title, is_error)
 
     def __str__(self):
-
-        # XXX Consider how we are to handle the cases this logic was trying
-        # to cover
-        #if self._wrote:
-        #    if self._chunking:
-        #        return '0\r\n\r\n'
-        #    else:
-        #        return ''
         raise NotImplementedError
 
 
@@ -256,7 +223,6 @@ def publish_module(environ, start_response,
     stderr = StringIO()
     response = _response_factory(stdout=stdout, stderr=stderr)
     response._http_version = environ['SERVER_PROTOCOL'].split('/')[1]
-    response._http_connection = environ.get('CONNECTION_TYPE', 'close')
     response._server_version = environ.get('SERVER_SOFTWARE')
 
     request = _request_factory(environ['wsgi.input'], environ, response)

src/ZPublisher/tests/test_WSGIPublisher.py

@@ -55,61 +55,6 @@ def test_finalize_skips_setting_content_length_if_missing_w_streaming(self):
         response.finalize()
         self.assertFalse(response.getHeader('Content-Length'))
 
-    def test_finalize_HTTP_1_0_keep_alive_w_content_length(self):
-        response = self._makeOne()
-        response._http_version = '1.0'
-        response._http_connection = 'keep-alive'
-        response.setBody('TESTING')
-        response.finalize()
-        self.assertEqual(response.getHeader('Connection'), 'Keep-Alive')
-
-    def test_finalize_HTTP_1_0_keep_alive_wo_content_length_streaming(self):
-        response = self._makeOne()
-        response._http_version = '1.0'
-        response._http_connection = 'keep-alive'
-        response._streaming = True
-        response.finalize()
-        self.assertEqual(response.getHeader('Connection'), 'close')
-
-    def test_finalize_HTTP_1_0_not_keep_alive_w_content_length(self):
-        response = self._makeOne()
-        response._http_version = '1.0'
-        response.setBody('TESTING')
-        response.finalize()
-        self.assertEqual(response.getHeader('Connection'), 'close')
-
-    def test_finalize_HTTP_1_1_connection_close(self):
-        response = self._makeOne()
-        response._http_version = '1.1'
-        response._http_connection = 'close'
-        response.finalize()
-        self.assertEqual(response.getHeader('Connection'), 'close')
-
-    def test_finalize_HTTP_1_1_wo_content_length_streaming_wo_http_chunk(self):
-        response = self._makeOne()
-        response._http_version = '1.1'
-        response._streaming = True
-        response.http_chunk = 0
-        response.finalize()
-        self.assertEqual(response.getHeader('Connection'), 'close')
-        self.assertEqual(response.getHeader('Transfer-Encoding'), None)
-        self.assertFalse(response._chunking)
-
-    def test_finalize_HTTP_1_1_wo_content_length_streaming_w_http_chunk(self):
-        response = self._makeOne()
-        response._http_version = '1.1'
-        response._streaming = True
-        response.http_chunk = 1
-        response.finalize()
-        self.assertEqual(response.getHeader('Connection'), None)
-
-    def test_finalize_HTTP_1_1_w_content_length_wo_chunk_wo_streaming(self):
-        response = self._makeOne()
-        response._http_version = '1.1'
-        response.setBody('TESTING')
-        response.finalize()
-        self.assertEqual(response.getHeader('Connection'), None)
-
     def test_listHeaders_skips_Server_header_wo_server_version_set(self):
         response = self._makeOne()
         response.setBody('TESTING')
@@ -187,18 +132,6 @@ def __len__(self):
         self.assertEqual(response.getHeader('Content-Length'),
                          '%d' % len(test_streamiterator.data))
 
-    #def test___str__already_wrote_not_chunking(self):
-    #    response = self._makeOne()
-    #    response._wrote = True
-    #    response._chunking = False
-    #    self.assertEqual(str(response), '')
-
-    #def test___str__already_wrote_w_chunking(self):
-    #    response = self._makeOne()
-    #    response._wrote = True
-    #    response._chunking = True
-    #    self.assertEqual(str(response), '0\r\n\r\n')
-
     def test___str___raises(self):
         response = self._makeOne()
         response.setBody('TESTING')