[ticket/11997] Add remove_web_root_path() in order to prevent incorrect URLs

Adding a call to this method to the redirect function will make sure that we
do not end up with incorrect URLs after using append_sid().

PHPBB3-11997

phpBB/includes/functions.php

@@ -2708,7 +2708,7 @@ function redirect($url, $return = false, $disable_cd_check = false)
 			}
 		}
 
-		$url = generate_board_url() . '/' . $url;
+		$url = generate_board_url() . '/' . $phpbb_path_helper->remove_web_root_path($url);
 	}
 
 	// Clean URL and check if we go outside the forum directory