Description:
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I use PHP via FastCGI on Win2008R2 IIS 7.5
Via "Process Monitor" I can see that the first time I access a php page, the
PHP-CGI.exe opens the php-file and then walks up the directory tree up to the
root.
It traverses/opens all directories till it reaches the Root-Folder (e.g. d:\)
This causes a huge performance impact when the PHP process doesnt have
permissions to travers the root-folder (or a folder outside the webroot).

Starting a webpage with redaxo e.g. lasts about 50 seconds instead of 1 or 2 seconds as many file includes/(accesses take place.

user_ini.filename is disabled (but PHP should anyway stop at the webroot).
safe_mode and open_basedir are off / not used

Test script:
---------------
- Create test.php with just one echo line
- Use PHP-CGI.exe via FastCGI on Windows 2008R2
- Open "Process monitor" and apply filter for php-cgi.exe
- Open test.php via browser
- See in process monitor how the process accesses not only test.php
  but also walks up the directory tree and traverses all parent folders
  till it reaches the root
- To test the performance impact you can delete the folder permission
  on the parent folders of the webroot and open the page several times
  (e.g. via curl and a loop)

Expected result:
----------------
PHP-cgi.exe should not travers folders outside the webroot.

Actual result:
--------------
PHP-cgi.exe opens/traverses all parent folders of the webroot up to the root.