CI redirect() HTTP code 303 auto-detection

redirect_303.patch

diff --git a/system/helpers/url_helper.php b/system/helpers/url_helper.php
index 40ce807..add7f72 100644
--- a/system/helpers/url_helper.php
+++ b/system/helpers/url_helper.php
@@ -526,7 +526,7 @@ if ( ! function_exists('redirect'))
         * @param       int
         * @return      string
         */
-       function redirect($uri = '', $method = 'auto', $http_response_code = 302)
+       function redirect($uri = '', $method = 'auto', $code = NULL)
        {
                if ( ! preg_match('#^https?://#i', $uri))
                {
@@ -538,14 +538,21 @@ if ( ! function_exists('redirect'))
                {
                        $method = 'refresh';
                }
+               elseif ($method !== 'refresh' && (empty($code) OR ! is_numeric($code)))
+               {
+                       $code = (isset($_SERVER['REQUEST_METHOD'], $_SERVER['SERVER_PROTOCOL'])
+                                       && $_SERVER['REQUEST_METHOD'] === 'POST'
+                                       && $_SERVER['SERVER_PROTOCOL'] === 'HTTP/1.1')
+                               ? 303 : 302;
+               }
 
-               switch($method)
+               switch ($method)
                {
                        case 'refresh':
                                header('Refresh:0;url='.$uri);
                                break;
                        default:
-                               header('Location: '.$uri, TRUE, $http_response_code);
+                               header('Location: '.$uri, TRUE, $code);
                                break;
                }
                exit;