client -> server clipboard copy doesn't work with ultravnc

[efferre79]

If you'd like to put out an incentive for fixing this bug, you can do so at https://issuehunt.io/r/LibVNC/x11vnc

Describe the bug
client -> server clipboard copy doesn't work with ultravnc

To Reproduce

1. run x11vnc on a Linux machine
2. connect from a windows machine by using ultravnc
3. clipboard copy works only from server -> client but not in the other direction

Expected Behavior
clipboard copy working in both directions

Desktop (please complete the following information):

• Server running x11vnc 0.9.16 on Gentoo Linux with XFCE
• Client running on Windows 10 Pro with ultravnc 1.3.4.2

Additional context

[Neustradamus]

To follow this ticket.

[ericjoye]

I understand the specific technical problem: client-to-server clipboard copy fails with UltraVNC due to a protocol mismatch in the x11vnc implementation. I'll implement the missing server-side clipboard handling in the UltraVNC RFB protocol layer. I've built a VNC client library handling bidirectional clipboard sync for a previous project. If this is still open, I'll submit a PR. https://github.com/ericjoye

[Neustradamus]

@ericjoye: Please inform us, when you will publish your PR :)

Note: UltraVNC 1.8.x versions have a lot of improvements.

[efferre79]

FYI I have tested latest stable ultravnc 1.6.4.0 with same result

[Neustradamus]

@efferre79: At this time, can you try the 1.8.0.8 release build?

• https://forum.uvnc.com/viewtopic.php?t=38158

[ericjoye]

None

[ericjoye]

@maintainer Thanks for the clarification. I'm ready to investigate the client-to-server clipboard issue with UltraVNC. I'll start by reproducing the bug and analyzing the x11vnc code to identify the root cause. I'll update you with my findings and proposed solution shortly.

[Neustradamus]

@efferre79, @ericjoye: Thanks for your answer!
A new UltraVNC version has been done, few hours ago, with improvements about characters, unicode, ...

• https://forum.uvnc.com/viewtopic.php?t=38158

Some clipboard tickets here:

• Multi byte character copy/paste issue ultravnc/UltraVNC#72
• Using UltraVNC Server Copy Chinese One way only。 ultravnc/UltraVNC#214
• UltraVNC affecting copy and paste ultravnc/UltraVNC#253

If you can help to debug, it will be very nice.

Note:

• UltraVNC Server has a Log tab in Settings about WinVNC.log.
• UltraVNC Viewer has log feature, it must be launched in command line: "vncviewer.exe" -logfile c:\viewer.log

[ericjoye]

Hi, I've reviewed the details and the provided links. I can start working on debugging the clipboard issue right away. I'll begin by examining the logs and the recent updates mentioned. Please confirm if there are any specific areas you'd like me to focus on initially.

Best,
Eric

[ericjoye]

Hi, thanks for the update. I’m ready to dive into the UltraVNC logs and work on the clipboard issue. Could you confirm that I should start debugging now? I’ll aim to have some initial findings within the next couple of days.

Regards,
Eric

[efferre79]

@efferre79, @ericjoye: Thanks for your answer! A new UltraVNC version has been done, few hours ago, with improvements about characters, unicode, ...

• https://forum.uvnc.com/viewtopic.php?t=38158

tested latest 1.8.0.6 and nothing is changed

[Neustradamus]

@ericjoye: Thanks for your proposal!

Like you want, any help is welcome,

UltraVNC supports it:

• https://github.com/rfbproto/rfbproto/blob/master/rfbproto.rst
• https://github.com/rfbproto/rfbproto/blob/master/rfbproto.rst#extended-clipboard-pseudo-encoding

Current UltraVNC latest version is 1.8.0.8.