Issue 2682 - Fix GAE dispatcher default port handling

modules/rietveld/files/wrapper.py

 #!/usr/bin/env python
 
 from ConfigParser import SafeConfigParser
 import hashlib
 import hmac
 import json
 import os
 import re
 import sys
 import urllib
@@ skipping 185 matching lines @@
 
     response.set_email(email)
     response.set_user_id(user_id)
     response.set_auth_domain(user_service_stub._DEFAULT_AUTH_DOMAIN)
     response.set_is_admin(is_admin)
     response.set_client_id(client_id)
     response.add_scopes(OAUTH2_SCOPE)
 
   user_service_stub.UserServiceStub._Dynamic_GetOAuthUser = _Dynamic_GetOAuthUser
 
+def dispatch_tasks_to_user_port():
+  """
+  By default, the dispatcher assumes port 80 for target authorities that
+  only contain a hostname but no port part. This hard-coded behavior is
+  altered in function dispatch_tasks_to_user_port() so that the port given
+  as --port option to the appserver-script is used instead. Without this
+  monkey-patch, dispatching tasks from an application run behind a HTTP
+  proxy server on port 80 will fail, because applications will omit the
+  default port when addressing resources.
+  """
+  from google.appengine.tools.devappserver2.dispatcher import Dispatcher
+  from google.appengine.api import request_info
+
+  resolve_target = Dispatcher._resolve_target
+
+  def callback(dispatcher, authority, path):
+    hostname, port = authority.split(":") if ":" in authority else (authority, dispatcher._port)
+    new_authority = "%s:%d" % (hostname, port)
+    result = resolve_target(dispatcher, new_authority, path)
+    return result
+
+  Dispatcher._resolve_target = callback
 
 if __name__ == '__main__':
   engine_dir = '/opt/google_appengine'
   storage_path = '/var/lib/rietveld'
 
   script_name, script_file = setup_paths(engine_dir)
   adjust_server_id()
   fix_request_scheme()
 
   if script_name == 'dev_appserver.py':
     config = read_config(os.path.join(storage_path, 'config.ini'))
 
     set_storage_path(storage_path)
     replace_runtime()
     protect_cookies(config.get('main', 'cookie_secret'))
     enable_oauth2(
       config.get('oauth2', 'client_id'),
       config.get('oauth2', 'client_secret'),
       config.get('main', 'admins').split()
     )
+    dispatch_tasks_to_user_port()
 
   execfile(script_file)