Hi Corinna,

Thanks for your advice.

On Fri, 8 Mar 2019 15:11:18 +0100 Corinna Vinschen wrote:
> > In Linux, connect() in the client returns befor the
> > server calls accept(). However, in cygwin, connect()
> > does not return until the server calls accept().
> 
> This is a result of the handshake to exchange credentials for
> getpeereid().  To workaround this issue, try building screen
> with a tweak.  Server and as client should call
> 
>   setsockopt (sock, SOL_SOCKET, SO_PEERCRED, NULL, 0);
> 
> before calling accept or connect.

Following your advice, I tried the patch attached and
confirmed the problem regarding -Q option is solved.

-- 
Takashi Yano <takashi.yano@nifty.ne.jp>