core-bundle/src/Resources/contao/library/Contao/Idna.php
public static function decode($strDomain)
	{
		if ($strDomain == '')
		{
			return '';
		}

		$objPunycode = new Punycode();

		try
		{
			return $objPunycode->decode($strDomain);
		}
		catch (LabelOutOfBoundsException $e)
		{
			return '';
		}
	}
public static function decode($strDomain)
	{
		if ($strDomain == '')
		{
			return '';
		}

		$objPunycode = new Punycode();

		try
		{
			return $objPunycode->decode($strDomain);
		}
		catch (LabelOutOfBoundsException $e)
		{
			return '';
		}
	}
Decode an internationalized domain name

@param string $strDomain The domain name

@return string The decoded domain name