request.folder no longer ends with os.sep

examples/app.example.yaml

@@ -1,7 +1,7 @@
 #  For Google App Engine deployment, copy this file to app.yaml
 #  and edit as required
-#  See http://code.google.com/appengine/docs/python/config/appconfig.html
+#  See https://cloud.google.com/appengine/docs/standard/python/config/appref
-#  and http://web2py.com/book/default/chapter/11?search=app.yaml
+#  and http://www.web2py.com/book/default/chapter/13#Deploying-on-Google-App-Engine
 
 application: yourappname
 version: 1

gluon/main.py

@@ -357,7 +357,7 @@ def wsgibase(environ, responder):
 
                 request.update(
                     client=client,
-                    folder=abspath('applications', app) + os.sep,
+                    folder=abspath('applications', app),
                     ajax=x_req_with == 'xmlhttprequest',
                     cid=env.http_web2py_component_element,
                     is_local=(env.remote_addr in local_hosts and client == env.remote_addr),