Re: GNUstep applications via ssh

[Fred Kiefer]

Andreas Höschler wrote:
> Hi all,
> 
> I am trying to run a GNUstep application on one host and displaying it
> on another tunnelling X11 throught ssh. Actually I am using Sun Secure
> Global Desktop which allows to do exactly that.
> 
> application server            SGD Server                Native SGD client
> ==============            =========                ==============
> GNUstep            <- ssh ->    tarantella        <- protocol->    MacOSX
> 
> The X11 stuff has to go from the application server to the SGD server.
> In my special case these two processes are running on the same machine.
> SGD allows to access X applications via telnet or ssh. When I use telnet
> for the conenction method it works. If I use ssh it does not. While
> trying to start Terminal.app (other GNUstep applications behave equally)
> I get the following
> 
> 2007-08-28 13:43:31.029 Terminal[23395] Loading 3 user defined AppKit
> bundles
> 2007-08-28 13:43:31.050 Terminal[23395]
> 2007-08-28 13:43:31.054 Terminal[23395]
> 2007-08-28 13:43:31.086 Terminal[23395]
> Xlib:  extension "MIT-SHM" missing on display "localhost:12.0".
> 2007-08-28 13:43:32.117 Terminal[23395] Waited for a second, but the X
> system never made the window visible
> 2007-08-28 13:43:32.120 Terminal[23395] Failed to determine offsets for
> style 1
> 2007-08-28 13:43:32.137 Terminal[23395] Failed to determine offsets for
> style 2
> 2007-08-28 13:43:32.140 Terminal[23395] Failed to determine offsets for
> style 3
> 2007-08-28 13:43:32.143 Terminal[23395] Failed to determine offsets for
> style 4
> 2007-08-28 13:43:32.146 Terminal[23395] Failed to determine offsets for
> style 5
> 2007-08-28 13:43:32.149 Terminal[23395] Failed to determine offsets for
> style 6
> 2007-08-28 13:43:32.151 Terminal[23395] Failed to determine offsets for
> style 7
> 2007-08-28 13:43:32.153 Terminal[23395] Failed to determine offsets for
> style 8
> 2007-08-28 13:43:32.156 Terminal[23395] Failed to determine offsets for
> style 9
> 2007-08-28 13:43:32.158 Terminal[23395] Failed to determine offsets for
> style 10
> 2007-08-28 13:43:32.160 Terminal[23395] Failed to determine offsets for
> style 11
> 2007-08-28 13:43:32.162 Terminal[23395] Failed to determine offsets for
> style 12
> 2007-08-28 13:43:32.164 Terminal[23395] Failed to determine offsets for
> style 13
> 2007-08-28 13:43:32.166 Terminal[23395] Failed to determine offsets for
> style 14
> 2007-08-28 13:43:32.169 Terminal[23395] Failed to determine offsets for
> style 15
> 2007-08-28 13:43:32.263 Terminal[23395] _appIconInit <NSIconWindow:
> 0x183848>
> 2007-08-28 13:43:32.364 Terminal[23395] WARNING: Failed to retrieve
> MenuServer application proxy
> 2007-08-28 13:43:32.364 Terminal[23395] registerAsServiceProvider Terminal
> 2007-08-28 13:43:32.684 Terminal[23395]
> 2007-08-28 13:43:32.684 Terminal[23395] activateIgnoringOtherApps 1
> _app_is_active 0 .....
> 2007-08-28 13:43:32.685 Terminal[23395] posting
> NSApplicationWillBecomeActiveNotification...
> 2007-08-28 13:43:32.685 Terminal[23395] WARNING: Failed to retrieve
> MenuServer application proxy
> 2007-08-28 13:43:32.700 Terminal[23395] <TerminalApplication: 0x181e28>
> _app_is_active = YES
> 2007-08-28 13:43:32.700 Terminal[23395] _unhide_on_activation 1
> 2007-08-28 13:43:32.701 Terminal[23395] No key on activation NSMenu:
> Terminal (Normal) <NSMenuPanel: 0x2033e8>
> 2007-08-28 13:43:32.701 Terminal[23395] GSServerForWindow: <XGServer:
> 0x227638>
> 2007-08-28 13:43:32.790 Terminal[23395] posting
> NSApplicationDidBecomeActiveNotification...
> 2007-08-28 13:43:32.793 Terminal[23395] activateIgnoringOtherApps 1
> _app_is_active 1 Done!
> 2007-08-28 13:43:32.805 Terminal[23395] styleoffsets ... guessing offsets
> 2007-08-28 13:43:32.805 Terminal[23395] styleoffsets ... guessing offsets
> ...
> 
> Then the whole session (window maker) dies and I am back at the login
> panel (actually ttwebtop).
> I suppose "Xlib:  extension "MIT-SHM" missing on display
> "localhost:12.0"" is important here. I am using art. What does this
> message try to tell me? Window Maker comes up fine. I can also start
> (successfully) other X apps (xterm,..), but no GNUstep apps. Any idea
> why this fails?
> 

That X is not able to use shared memory between the two systems is not
too surprising and should also not be the reason of your problem.
It could be that the code in _checkStyle: (in file XGServerWindow) is
causing it. Here we take the screen 0 to create our temporary windows.
The method windowlist also uses screen 0. Using defScreen here seems
like the better option. I will implement this.

Fred