TYPO3 Core

IMHO 1 case is not covered.

It is very close to

            'first HTTP_X_FORWARDED_HOST from configured proxy' => [
                [
                    'HTTP_HOST' => '',
                    'REMOTE_ADDR' => '123.123.123.123',
                    'HTTP_X_FORWARDED_HOST' => 'www.domain1.com, www.domain2.com,'
                ],
                [
                    'reverseProxyIP' => '123.123.123.123',
                    'reverseProxyHeaderMultiValue' => 'first',
                ],
                'www.domain1.com',
            ],

, but with a set HTTP_HOST. The result shall be the same.