Checks whether an entity body is received by the server when sent via XHR send().
The client sends a single name/value pair as application/x-www-form-urlencoded, and the server checks for this name via Python CGI. I don't *think* there should be any problems with such a test - writing a more trustworthy one would be quite a bit more work though, at least with my current setup.
Note that IE seems to pass the GET test because it converts the method to POST (?!). That really means the test is indeterminate though.