app-functions-fn.fs.php.diff

diff --git a/app/functions/fn.fs.php b/app/functions/fn.fs.php
index 87d88b7..f28a5fe 100644
--- a/app/functions/fn.fs.php
+++ b/app/functions/fn.fs.php
@@ -308,7 +308,7 @@ function fn_get_file_type($filename, $not_available_result = 'application/octet-
 
     $types = fn_get_ext_mime_types('ext');
 
-    $ext = fn_get_file_ext($filename);
+    $ext = fn_strtolower(fn_get_file_ext($filename));
 
     if (!empty($types[$ext])) {
         $file_type = $types[$ext];
@@ -665,12 +665,7 @@ function fn_rm($source, $delete_root = true, $pattern = '')
  */
 function fn_get_file_ext($filename)
 {
-    $i = strrpos($filename, '.');
-    if ($i === false) {
-        return '';
-    }
-
-    return substr($filename, $i + 1);
+    return (string)pathinfo($filename, PATHINFO_EXTENSION);
 }
 
 /**