X-Spam-Check-By: sourceware.org Message-ID: <2fc802c00603270955m5aab74d9s592c663ff905bae4@mail.gmail.com> Date: Mon, 27 Mar 2006 18:55:14 +0100 From: "David Picton" To: cygwin AT cygwin DOT com Subject: Sshd: problem with X11 passthru MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Disposition: inline Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com Delivered-To: mailing list cygwin AT cygwin DOT com Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by delorie.com id k2RHtLkO001838 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!) -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/