Suppose to have proxy settings configured to use automatic proxy via PAC script.
Because of this, also suppose connection to https://address1 is made through a proxy server, while connection to https://address2 is made directly.
Open konqueror (doesn't matter what html engine is used) then connect to https://address1. Now try to connect to https://address2, the request will fail.
To reproduce create a local proxy.pac file containing the following:
function FindProxyForURL(url, host) {
        if (shExpMatch(host, "*.kde.org")) {
                return "PROXY some.valid.proxy:port";
        }

        return "DIRECT";
}
and configure automatic proxy setting to use proxy.pac file.
Connect to https://bugs.kde.org (this should go through proxy), then try to do a request to another https url not in kde.org domain.