php app update: Invalid character in filename - php

Question

Problem when uploading php application which uses Wordpress
* version - 1.8.0
* language - php
* operating system - Windows 7
Update to the GAE shows the below error for many files. Tried renaming few files but the error pops for another file and so on. These are wordpress 3.5.1 files.
Error 400: --- begin server output ---
Invalid character in filename: __static__\wordpress/wp-includes/css/admin-bar.css
--- end server output ---
The app.yaml content:
-------------------------------------------
application: fargocricketclub
version: 1
runtime: php
api_version: 1
threadsafe: yes
handlers:
- url: /(.*\.(htm$|html$|css$|js$))
static_files: wordpress/\1
upload: wordpress/(.*\.(htm$|html$|css$|js$))
application_readable: true
- url: /wp-content/(.*\.(ico$|jpg$|png$|gif$))
static_files: wordpress/wp-content/\1
upload: wordpress/wp-content/(.*\.(ico$|jpg$|png$|gif$))
application_readable: true
- url: /(.*\.(ico$|jpg$|png$|gif$))
static_files: wordpress/\1
upload: wordpress/(.*\.(ico$|jpg$|png$|gif$))
- url: /wp-admin/(.+)
script: wordpress/wp-admin/\1
secure: always
- url: /wp-admin/
script: wordpress/wp-admin/index.php
secure: always
- url: /wp-login.php
script: wordpress/wp-login.php
secure: always
- url: /wp-cron.php
script: wordpress/wp-cron.php
login: admin
- url: /xmlrpc.php
script: wordpress/xmlrpc.php
- url: /(.+)?/?
script: wordpress/index.php

Answer 1

I believe that this is fixed in the 1.8.1 release of App Engine, using the solution proposed above to join the path using the OS specific path separator.

Answer 2

Issue seen in PHP & Python 1.8.1 deployments on Windows when using application_readable. Issue flagged: https://code.google.com/p/googleappengine/issues/detail?id=9558
Work around:
replaced os.path.join with posixpath.join in google\appengine\tools\appcfg.py