dont' override SERVER_* by the Host header

Gunicorn shouln't override the SERVER_* by the Host header. The client
will take care about it during the URL reconstruction if needed.

Since the spec don't support unix sockets, Gunicorn is using the HOST
heeader when available to create viable SERVER_* if possible so the
application and framworks will be happy. When the Host Header is not
available (SocketPath, '') is returned.

fix #628

gunicorn/http/wsgi.py

@@ -78,17 +78,22 @@ def proxy_environ(req):
 def create(req, sock, client, server, cfg):
     resp = Response(req, sock, cfg)
 
+    # set initial environ
     environ = default_environ(req, sock, cfg)
 
+    # default variables
+    host = None
     url_scheme = "https" if cfg.is_ssl else "http"
     script_name = os.environ.get("SCRIPT_NAME", "")
 
+    # set secure_headers
     secure_headers = cfg.secure_scheme_headers
     if client and not isinstance(client, string_types):
         if ('*' not in cfg.forwarded_allow_ips
                 and client[0] not in cfg.forwarded_allow_ips):
             secure_headers = {}
 
+    # add the headers tot the environ
     for hdr_name, hdr_value in req.headers:
         if hdr_name == "EXPECT":
             # handle expect
@@ -97,8 +102,8 @@ def create(req, sock, client, server, cfg):
         elif secure_headers and (hdr_name in secure_headers and
               hdr_value == secure_headers[hdr_name]):
             url_scheme = "https"
-        elif hdr_name == "HOST":
+        elif hdr_name == 'HOST':
-            server = hdr_value
+            host = hdr_value
         elif hdr_name == "SCRIPT_NAME":
             script_name = hdr_value
         elif hdr_name == "CONTENT-TYPE":
@@ -113,8 +118,10 @@ def create(req, sock, client, server, cfg):
             hdr_value = "%s,%s" % (environ[key], hdr_value)
         environ[key] = hdr_value
 
+    # set the url schejeme
     environ['wsgi.url_scheme'] = url_scheme
 
+    # set the REMOTE_* keys in environ
     # authors should be aware that REMOTE_HOST and REMOTE_ADDR
     # may not qualify the remote addr:
     # http://www.ietf.org/rfc/rfc3875
@@ -124,26 +131,42 @@ def create(req, sock, client, server, cfg):
         environ['REMOTE_ADDR'] = client[0]
         environ['REMOTE_PORT'] = str(client[1])
 
+    # handle the SERVER_*
+    # Normally only the application should use the Host header but since the
+    # WSGI spec doesn't support unix sockets, we are using it to create
+    # viable SERVER_* if possible.
     if isinstance(server, string_types):
         server = server.split(":")
         if len(server) == 1:
-            if url_scheme == "http":
+            # unix socket
-                server.append("80")
+            if host and host is not None:
-            elif url_scheme == "https":
+                server = host.split(':')
-                server.append("443")
+                if len(server) == 1:
+                    if url_scheme == "http":
+                        server.append(80),
+                    elif url_scheme == "https":
+                        server.append(443)
+                    else:
+                        server.append('')
             else:
+                # no host header given which means that we are not behind a
+                # proxy, so append an empty port.
                 server.append('')
     environ['SERVER_NAME'] = server[0]
     environ['SERVER_PORT'] = str(server[1])
 
+    # set the path and script name
     path_info = req.path
     if script_name:
         path_info = path_info.split(script_name, 1)[1]
     environ['PATH_INFO'] = unquote_to_wsgi_str(path_info)
     environ['SCRIPT_NAME'] = script_name
 
+    # override the environ with the correct remote and server address if
+    # we are behind a proxy using the proxy protocol.
     environ.update(proxy_environ(req))
 
+    print(environ)
     return resp, environ