reason : Drupal is using basename() function on filename extracting. But basename function with php5 is not safe locale. If you use utf-8 encoding on cjk like charset, basename will not work exatly.
solution : First. don't use php5, and use php4.
Second. make locale indepent basename function (ex: drupal_basename() )
function drupal_basename($path,$prefix = '') {
$path = preg_replace('|^.+[\\/]|', '', $path);
if ($prefix) {
$path = preg_replace('|'. preg_quote($prefix) .'$|', '', $path);
}
return $path;
}
I changed pattern '|^.+[\\/]|' to '/([^\/]+)\//'.
function drupal_basename($path,$suffix = '') {
$path = preg_replace('/([^\/]+)\//', '', $path);
if ($suffix) {
$path = preg_replace('/'.preg_quote($suffix).'$/', '', $path);
}
return $path;
}
And replace three files to use drupal_basename function.
* file.inc
* common.inc
* locale.inc
Reference : http://drupal.org/node/278425