When JPATH_ROOT is an empty string –i.e. we run inside a chroot jail–…

… JPath::check() always raises error 20 (snooping out of bounds). By definition of the chroot jail, we can snoop out of bounds in this case. Therefore this check should always succeed. Ergo the proposed change.

libraries/joomla/filesystem/path.php

@@ -177,7 +177,7 @@ public static function check($path, $ds = DIRECTORY_SEPARATOR)
 		}
 
 		$path = JPath::clean($path);
-		if (strpos($path, JPath::clean(JPATH_ROOT)) !== 0)
+		if (!empty(JPATH_ROOT) && strpos($path, JPath::clean(JPATH_ROOT)) !== 0)
 		{
 			// Don't translate
 			JError::raiseError(20, 'JPath::check Snooping out of bounds @ ' . $path);