WordPress Version: 6.1
/**
* Retrieves a canonical form of the provided charset appropriate for passing to PHP
* functions such as htmlspecialchars() and charset HTML attributes.
*
* @since 3.6.0
* @access private
*
* @see https://core.trac.wordpress.org/ticket/23688
*
* @param string $charset A charset name.
* @return string The canonical form of the charset.
*/
function _canonical_charset($charset)
{
if ('utf-8' === strtolower($charset) || 'utf8' === strtolower($charset)) {
return 'UTF-8';
}
if ('iso-8859-1' === strtolower($charset) || 'iso8859-1' === strtolower($charset)) {
return 'ISO-8859-1';
}
return $charset;
}