Wikimedia Bugzilla is closed!

I have a very simple test case:
		$user->setEmail( $email );
		$user->setPassword( $password );
		$status = $user->addToDatabase();

		if ( !$status->isOK() ) {
			throw new MWException( $status->getWikiText() );
		}

		// Need to have an id first
		$user->addGroup( 'translate-sandboxed' );
		var_dump( $user->getGroups() ); die();

This prints:
array(2) {
  [0]=>
  string(19) "translate-sandboxed"
  [1]=>
  string(19) "translate-sandboxed"
}

It should return it only once.