Add extra stuff to the WSGI environ sent during invites

Also set SERVER_NAME and SERVER_PORT for consistency, and set up a
vendor CKAN key to be able to identify the environ as one of the ones
used for sending the WSGI invites. This is needed so the `is_flask`
function correctly returns the relevant value based on the request
environ.

ckan/common.py

@@ -31,7 +31,9 @@ def is_flask():
     Currently using the presence of `flask.request`, though we may want to
     change that for something more robust.
     '''
-    if flask.request:
+    if (flask.request and
+            (flask.request.environ.get('ckan.app') == 'flask_app' or
+             flask.request.environ.get('ckan.wsgiparty.setup'))):
         return True
     else:
         return False

ckan/config/middleware/__init__.py

@@ -99,12 +99,19 @@ def send_invitations(self, apps):
         PATH = '/__invite__/'
         # We need to send an environ tailored to `ckan.site_url`, otherwise
         # Flask will return a 404 for the invite path (as we are using
-        # SERVER_NAME). Existance of `ckan.site_url` in config has already
-        # been checked.
+        # SERVER_NAME on Flask config). Existance of `ckan.site_url` in config
+        # has already been checked.
+        # Also add a key to be able to identify this request environ as a WSGI
+        # party setup one.
         parts = urlparse.urlparse(config.get('ckan.site_url'))
         environ_overrides = {
-            'HTTP_HOST': parts.netloc,
+            'HTTP_HOST': str(parts.netloc),
+            'SERVER_NAME': str(parts.hostname),
+            'ckan.wsgiparty.setup': True,
         }
+        if parts.port:
+            environ_overrides['SERVER_PORT'] = str(parts.port)
+
         for app_name, app in apps.items():
             environ = create_environ(PATH, environ_overrides=environ_overrides)
             environ[self.partyline_key] = self.operator_class(self)