Package: nx-libs Version: 3.5.0.27 Severity: normal
If you run a VirtualBox VM with its display running under X2Go, the VM's clipboard sharing fails to work in either direction.
You cannot copy and paste text between the VM and an app running under X2Go server, nor can you copy and paste text between the VM and an app running on the X2Go Client system.
(I believe VirtualBox VMs use SDL to interact with the X server, which in this case is nxagent. This differs from the VirtualBox GUI, which is written in QT.)
Specifically, when the X sesssion starts on the guest, a VirtualBox-provided script for X calls "VBoxClient --clipboard" to start the clipboard service. The service runs as the user logged into the guest. However, this service fails to stay running, and thus the clipboard sharing does not work.
If you launch the VirtualBox VM on the local X.org X server, the guest's clipboard service stays running and clipboard sharing works. You can also launch the VM in RDP headless mode from x2go (so the VM does not render its display to any nxagent). In this use case, the clipboard service stays running and clipboard sharing works.
The strange part is that the configuration of the host affects the behavior of the guest. It makes sense though because it's a bug in the guest's code to integrate with the host.
Also, when you do call "VBoxClient --clipboard", it returns 0. And if you call it after the X11 session has already started, the problem still occurs.
In x2goclient, I tried turning on and off the following setting, but it had no effect: Options -> Settings -> X-Server settings -> do not use primary clipboard
My theory is that this is a bug in nx-libs, and that the bug is probably related to nx-libs being forked from such an old X.org codebase. It is worth looking into whether other SDL apps have clipboard trouble with X2Go on Ubuntu 14.04. (It's also worth testing an older release of Ubuntu as the host OS, since it would have an older release of SDL.)
Host system:
OS: Ubuntu 14.04.1 64-bit with latest bugfix & security updates nxagent: 2:3.5.0.27-0~446~ubuntu14.04.1 x2goserver: 4.0.1.15-0~847~ubuntu14.04.1 x2goserver-xsession: 4.0.1.15-0~847~ubuntu14.04.1 VirtualBox 4.3.14 (from download.virtualbox.org)
"Shared Clipboard" is set to "Bidirectional" for the VM
$ cat /etc/x2go/x2goagent.options | grep -v '^#' | grep -v '^$' X2GO_NXAGENT_DEFAULT_OPTIONS="" X2GO_NXAGENT_DEFAULT_OPTIONS+=" -extension XFIXES" X2GO_NXAGENT_DEFAULT_OPTIONS+=" -nolisten tcp"
Guest OS:
Ubuntu 12.04.5 64-bit with precise HWE stack, the virtual kernel, and all the latest bugfix & security updates OS-provided XFCE virtualbox-guest-dkms: 4.1.12-dfsg-2ubuntu0.6 virtualbox-guest-utils: 4.1.12-dfsg-2ubuntu0.6 virtualbox-guest-x11: 4.1.12-dfsg-2ubuntu0.6 Configured according to: https://github.com/mikedep333/duckpan-vagrant/tree/duckduckhack-vm The aforementioned script is: /etc/X11/Xsession.d/98vboxadd-xclient (I'm sure a different script would be used for distros like CentOS which lack the /etc/X11/Xsession.d/ folder).
Client system:
Windows 8.1 64-bit with Update 1 and all the minor/monthly updates available X2GoClient 4.0.2.1+hotfix1+build3