After finding that basePath points to /mysite/htdocs/myapp/protected/ rather than the expected "the root directory of the application", which /protected/ is NOT in my opinion, I searched high and low to find that there is not a property that points to the true application root directory.
For example, if my entry script resides in /mysite/htdocs/myapp/ then a property that returns that value would be very useful when creating features such as file uploads.
We have properties for all other essential file system paths, why not this one?