Further GET vars are missing in language switch
The extension currently just uses the current
page id and
sys_language_uid to generate the new URL.
This will remove all existing
GET-Parameters on the current page. E.g. you are on a detail page with further parameters like the uid of a record for a further extension and change the system language using your extension, the other extension can break.
Because your extension will remove the other Parameters and the extension will no longer have a uid for show the record. Most extbase extensions will throw an exception.