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Date: Tue, 28 Mar 2006 09:37:28 +0200
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: Sshd: problem with X11 passthru
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On Mar 27 18:55, David Picton wrote:
> I have encountered a problem with the sshd server when the client
> specifies X11 passthru i.e. ssh -Y or ssh -X.
> 
> The allocation of virtual displays doesn't work correctly if two or
> more X11-enabled sessions run at the same time.
> 
> As I understand it, the server should give each session a unique
> display number under these circumstances:  localhost:10.0,
> localhost:11.0, localhost:12.0 etc.
> 
> Instead, all the sessions have DISPLAY=localhost:10.0 at the same
> time.  This causes a variety of problems - loss of access to the X
> server (due to changed Magic Cookie authorization on the server when a
> new client connects), or the appearance of windows on the wrong server
> (if two different clients connect).
> 
> (Note that setting up Magic Cookie authorization on the client machine
> makes no difference to this bug.  It prevents the client-side warning
> about 'fake authorization' but it doesn't cure any of the server-side
> problems!)

I don't see anything Cygwin specific here.  You should ask your
question on a mailing list or newsgroup dedicated to OpenSSH.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat

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