TYPO3 Core

Generation of an absolute TypoLink with a non-standard port fails (On TYPO3 7.6 it works as excepted).

In 7.6 there was an additional check (ContentObjectRenderer)

$tsfe->config['config']['typolinkCheckRootline']

that not on our Installation not matched and so target domain is set to current domain here:

// If no domain records are defined, use current domain:
$currentUrlScheme = parse_url($this->getEnvironmentVariable('TYPO3_REQUEST_URL'), PHP_URL_SCHEME);
if ($targetDomain === '' && ($conf['forceAbsoluteUrl'] || $absoluteUrlScheme !== $currentUrlScheme)) {
     $targetDomain = $currentDomain;
}

As result: $currentDomain and $targetDomain are equals and contains the port.

In 8.7 and 9.x the typolinkCheckRootline was removed in PageLinkBuilder, so currentDomain set to the sys_domain-Record, which should not contains the port. This means, that $currentDomain != $targetDomain, so PageLinkBuilder build the url, but missed the port