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