Index: includes/file.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/file.inc,v
retrieving revision 1.169
diff -r1.169 file.inc
1880,1882c1880,1885
<   foreach ($mapping as $ext_preg => $mime_match) {
<     if (preg_match('!\.(' . $ext_preg . ')$!i', $filename)) {
<       return $mime_match;
---
> 
>   $last_dot = strrpos($filename, '.');
>   if ($last_dot !== FALSE) {
>     $ext = drupal_strtolower(drupal_substr($filename, $last_dot+1, drupal_strlen($filename)-$last_dot));
>     if (isset($mapping[$ext])) {
>       return $mapping[$ext];
1927c1930
<  */
\ No newline at end of file
---
>  */