How to validate google webmaster tools with diazo
On the CMS Plone I'm used to validate google webmaster tools by adding in ZMI the file provided by Google during the validation process.

But once you have activated a diazo theme, Plone add doctype header.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml">
Google can't validate this and warn you about this:

To fix this there is a simple solution. grab the content of this file and create a Script (Python) in ZMI with id (filename Google has given to you, something like googlexxx.html)
Paste this code replacing CONTENT by the content of the file:
res = "CONTENT"
context.REQUEST.response.setHeader('X-Theme-Disabled', 'True')
return res
That way plone.app.theming will do nothing and your site will be validated by Google.
This apply also to any content/view you want to be not themed by diazo and is documented in plone.app.theming.
