Clipboard isn't updated from VNC-client, behaves oddly in general

[vermgit]

Describe the bug
My goal is to use the clipboard in both ways server -> client and client -> server. In the current version:

• the update server -> client works, but the content of the clipboard is sent automatically
• the other ways does not work at all
• the log seems to suggest that the clipboard handling lands in an infinite loop somehow

To Reproduce
Start x11vnc:

$ x11vnc -auth guess -debug_sel -nodpms -xdamage -repeat -rfbauth /home/nas/.vnc/passwd -rfbport 5900 -shared

Note that it doesn't make a difference to add -noxkb.

Simply wait, no need to press any keys or other activity. The logging of clipboard starts itself and never ends.

Copying something on the client into the clipboard doesn't seem to appear on the server.

Expected Behavior

• server accepts clipboard from client
• server doesn't send clipboard content to the client for no reason
• -debug_sel shows consistent output of single copy&paste actions (at least that would make sense to me)

Screenshots / Log-File
See enclosed log-file x11vnc.log

Desktop (please complete the following information):

• OS and version: XUbuntu 24.04 LTS (both client and server)
• Xorg version used: X.Org X Server 1.21.1.11
• Wayland version used: -
• x11vnc version: 0.9.16
• client: tigervnc-viewer 1.13.1+dfsg-2build2

Additional context
In my case on the server the word "team" is in the clipboard and the word "the" was selected with the mouse earlier. At the point of starting x11vnc no word is selected (but, having "the" selected doesn't change the log). The server then sends "the" as the content of the clipboard and my client sets the clipboard to that. In other words the server sets the client's clipboard even though no intended copy&paste activity occurred on the server.

I also installed autocutsel on both machines to see if I can make it work with it or it shows more that I can add here, but it doesn't.

Recently I updated both machines from XUbuntu 22.04 LTS. With the various current versions of the programs in that release it all had worked fine.

The general idea is to use x11vnc as a systemd-service.

[Martii]

Similar here in Kubuntu 24.04.x (core is Ubuntu just like others but using X11 still instead of Wayland).

Host client clipboard entries never appear on server clipboard (x11nvc). However server target clipboard does copy back to host client. Did work in 22.04.xx client to 22.04.xx server and 24.04.x client to 22.04.xx server.

Unfortunately normal 22.04 is EOLing around April so migrations are in progress and pulling hair out without bi-directional clipboard that used to work.

Tiger's vnc viewer is also set with AcceptClipboard=1 -SendClipboard=1 since the olden days.

Also found my distro's package is a few releases behind https://github.com/TigerVNC/tigervnc/releases

[Xist12gh]

Fixed by: LibVNC/libvncserver#639
At least Debian12 is still using 0.9.14 without this patch. Should be fixed when 0.9.15 is packaged. Maybe create a Bug for libvncserver in Debian or Ubuntu.
As far as I recon, 0.9.13 used in Debian11 does not support UTF8 Clipboard, which would explain the sudden change in behaviour

Also refer to #77
Maybe someone can implement UTF8 Clipboard now?

Edit: possibly the same issue in https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1034056

[Martii]

At least Debian12 is still using 0.9.14 without this patch. Should be fixed when 0.9.15 is packaged.

Certainly is unfortunate that their versioning range is around this packages range. 😸 Took me a moment to figure out you probably meant LibVNCServer-0.9.15.

Hope this change bubbles to this package soon. I really miss having bi-directional clipboard access.

$ loginctl show-session $(loginctl | grep $(whoami) | awk '{print $1}') -p Type
Type=x11

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 24.04.2 LTS
Release:        24.04
Codename:       noble

$ apt-cache policy libvncserver1
libvncserver1:
  Installed: 0.9.14+dfsg-1build2
  Candidate: 0.9.14+dfsg-1build2
  Version table:
 *** 0.9.14+dfsg-1build2 500
        500 http://us.archive.ubuntu.com/ubuntu noble/main amd64 Packages
        100 /var/lib/dpkg/status

$ apt-cache policy libvncclient1 
libvncclient1:
  Installed: 0.9.14+dfsg-1build2
  Candidate: 0.9.14+dfsg-1build2
  Version table:
 *** 0.9.14+dfsg-1build2 500
        500 http://us.archive.ubuntu.com/ubuntu noble/main amd64 Packages
        100 /var/lib/dpkg/status

$ apt-cache policy x11vnc
x11vnc:
  Installed: 0.9.16-10
  Candidate: 0.9.16-10
  Version table:
 *** 0.9.16-10 500
        500 http://us.archive.ubuntu.com/ubuntu noble/universe amd64 Packages
        100 /var/lib/dpkg/status

$ apt-cache policy tigervnc-viewer
tigervnc-viewer:
  Installed: (none)
  Candidate: 1.13.1+dfsg-2build2
  Version table:
     1.13.1+dfsg-2build2 500
        500 http://us.archive.ubuntu.com/ubuntu noble/universe amd64 Packages

$ apt-cache policy xtigervncviewer 
xtigervncviewer:
  Installed: 1.14.1-1ubuntu1
  Candidate: 1.14.1-1ubuntu1
  Version table:
 *** 1.14.1-1ubuntu1 100
        100 /var/lib/dpkg/status

Hmm... an update at https://sourceforge.net/projects/tigervnc/files/stable/1.15.0/ via https://github.com/TigerVNC/tigervnc/releases/tag/v1.15.0 .

$ apt-cache policy xtigervncviewer
xtigervncviewer:
  Installed: 1.15.0-1ubuntu1
  Candidate: 1.15.0-1ubuntu1
  Version table:
 *** 1.15.0-1ubuntu1 100
        100 /var/lib/dpkg/status

... no change in x11vnc's behavior.

[Xist12gh]

If you're in a hurry you can try what I've done:

Get the patch file of the pull request here https://patch-diff.githubusercontent.com/raw/LibVNC/libvncserver/pull/639.patch

Get the deb file source apt-get source libvncserver
Make sure you got the build deps apt-get build-dep libvncserver and apt install quilt

I had to remove the occurrences of include/ and src/ from the patch file using a text editor so it could be applied it to the package source.

Then apply it to the package patch set by quilt import 639.patch and try to apply with quilt push

Create a new changelog entry with dch -n and build your shiny new deb file with dpkg-buildpackage -uc -us -b

[sergiomb2]

we also have #255

I will check LibVNC/libvncserver#639