Description:
------------
when using domain relative urls with curl, this worked on php5 and also on php7.0

we are in the process of testing our software with php7.2 and see that we get a error in this case "<url> malformed".

I agree using the CURLOPT_URL option without absolute urls is not ideal, but since it worked in the past I would at least not expect a BC break with this behaviour in the php7.* series

Test script:
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        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, '/mytest');
        curl_exec($ch);
        
        $error = '';
        if (curl_errno($ch) != 0) {
            $error = curl_error($ch);
        }


var_dump($error);