TYPO3 Core

// use default scheme if needed

if (

// check for BE preview

!(t3lib_div::_GP('authCode') && t3lib_div::_GP('eID') === 'linkhandlerPreview') &&

// check for absolute URL with scheme

!(isset($conf['forceAbsoluteUrl.']['scheme']) && $conf['forceAbsoluteUrl.']['scheme']) &&

// check for page default url_scheme and general default config

$page['url_scheme'] == 0 && strlen($GLOBALS['TSFE']->config['config']['defaultUrlScheme']) > 0

) {

if ($GLOBALS['TSFE']->config['config']['defaultUrlScheme'] === 'http') {

$page['url_scheme'] = t3lib_utility_http::SCHEME_HTTP;

} else {

$page['url_scheme'] = t3lib_utility_http::SCHEME_HTTPS;

}

}