From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NJyGO-00071R-6k for qemu-devel@nongnu.org; Sun, 13 Dec 2009 18:54:08 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NJyGJ-00070H-Kh for qemu-devel@nongnu.org; Sun, 13 Dec 2009 18:54:07 -0500 Received: from [199.232.76.173] (port=34511 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NJyGJ-00070A-Io for qemu-devel@nongnu.org; Sun, 13 Dec 2009 18:54:03 -0500 Received: from mail-yw0-f171.google.com ([209.85.211.171]:35205) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NJyGJ-0006DZ-7l for qemu-devel@nongnu.org; Sun, 13 Dec 2009 18:54:03 -0500 Received: by ywh1 with SMTP id 1so2353887ywh.18 for ; Sun, 13 Dec 2009 15:54:02 -0800 (PST) Message-ID: <4B257E97.6000904@codemonkey.ws> Date: Sun, 13 Dec 2009 17:53:59 -0600 From: Anthony Liguori MIME-Version: 1.0 Subject: Re: [Qemu-devel] Question on QEMU's VNC Server hextile implementation References: <575929515.1599781260738392519.JavaMail.root@zmail05.collab.prod.int.phx2.redhat.com> In-Reply-To: <575929515.1599781260738392519.JavaMail.root@zmail05.collab.prod.int.phx2.redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Yaniv Kaul Cc: qemu-devel@nongnu.org Yaniv Kaul wrote: > According to the RFB protocol, section 6.6.4 (hextile encoding), regarding the 'ForegroundSpecified' bit, it says: 'If this bit is set then the SubrectsColoured bit must be zero.'. > It doesn't seem QEMU's VNC server does that. In fact, it looks like both bits are set. > I've verified against a different VNC server, and I didn't see this happening. > (it may be a Wireshark dissector bug, of course). > Yes, this definitely goes against the wording in the specification. It's also wasting bits on the wire. I'll work up a patch on Monday. I checked the real vnc client to make sure it handles this combination and it does. I think the reason the spec forbids this is that a SubrectsColoured invalidates the foreground color. Having the two is therefore not a useful combination because the foreground color won't actually be used for anything. We do invalidate the foreground color correctly but we're just sending out useless data so removing it's a good idea. Thanks for catching this! Regards, Anthony Liguori > TIA, > Y. > > >