fix for dirname(__FILE__) returning '/'

git-svn-id: http://dev.piwik.org/svn/trunk@1476 59fd770c-687e-43c8-a1e3-f5a4ff64c105

index.php

@@ -31,7 +31,7 @@ if(ini_get('session.save_handler') == 'user')
 	@ini_set('session.save_path', '');
 }
 
-define('PIWIK_DOCUMENT_ROOT', dirname(__FILE__));
+define('PIWIK_DOCUMENT_ROOT', dirname(__FILE__)=='/'?'':dirname(__FILE__));
 if(!defined('PIWIK_USER_PATH'))
 {
 	define('PIWIK_USER_PATH', PIWIK_DOCUMENT_ROOT);

piwik.php

@@ -17,7 +17,7 @@ $GLOBALS['PIWIK_TRACKER_DEBUG'] = false;
 define('PIWIK_TRACKER_MODE', true);
 error_reporting(E_ALL|E_NOTICE);
 
-define('PIWIK_DOCUMENT_ROOT', dirname(__FILE__));
+define('PIWIK_DOCUMENT_ROOT', dirname(__FILE__)=='/'?'':dirname(__FILE__));
 if(!defined('PIWIK_USER_PATH'))
 {
 	define('PIWIK_USER_PATH', PIWIK_DOCUMENT_ROOT);