Hmmm. That prevents an immediate crash, but may cause other problems. Here is a better fix: change lines 45,46 to:
if settings.APPEND_SLASH: if (len(old_url[1]) > 0): if (old_url[1][-1] != '/' and ('.' not in old_url[1].split('/')[-1]): new_url[1] = new_url[1] + '/' else: new_url[1] = '/' That should do it...