cmsRootPath does correctly determine root path if an "includes" directory exists at higher levels

The function cmsRootPath in CRM/Utils/System/Drupal.php starts at the root path and stops as soon as it finds any directory that has a /includes directory. This means, if you have a setup like I have:

/var/www --> This is the root of my live site
/var/www/includes --> This is the Drupal includes directory of my live site
/var/www/test --> This is the root of my test site
/var/www/test/includes ---> This is the includes directory of my test site.

Then cmsRootPath returns /var/www for both the live site (correct) and the test site (incorrect... should be /var/www/test).

I see two options to fix this bug:

(1) Simply use $_SERVER['DOCUMENT_ROOT'] instead of the complicated traversing of the path in the script.

(2) If (1) is not an option for some reason (maybe non-Apache web servers?), then I have attached a patch that causes the function to traverse the tree the other direction. I am not a CiviCRM developer, so I cannot guarantee the quality of the patch. I have tested it on my installation (Apache / php 5.2) and it seems to work. I have not tested in a Windows environment.

Basically, cmsRootPath needs to work from the deepest levels up to search for /includes.