Copy doesn't work, report "Cannot set X11 selection owner"

[cadem]

Describe the bug
I run an application (SecureCRT), but when I execute to copy a text, copy does not work, the text is able to pasted.
In the server log, the following error message is reported:

qt.qpa.clipboard: QXcbClipboard::setMimeData: Cannot set X11 selection owner
qt.qpa.clipboard: QXcbClipboard::setMimeData: Cannot set X11 selection owner
qt.qpa.clipboard: QXcbClipboard::setMimeData: Cannot set X11 selection owner
qt.qpa.clipboard: QXcbClipboard::setMimeData: Cannot set X11 selection owner
qt.qpa.clipboard: QXcbClipboard::setMimeData: Cannot set X11 selection owner

But I run other application, vscode , its copy always works.
And SecureCRT copy works sometime, I don't when the securecrt doesn't work.

To Reproduce
Steps to reproduce the behavior:

1. xpra start :101 --start=SecureCRT
2. through xpra ui start
3. no

System Information (please complete the following information):

• Server OS: run xpra server on an ubuntu docker on ubuntu server
• Client OS: windows server 2022
• Xpra Server Version :xpra v6.2.1-r0
• Xpra Client Version :xpra v6.2.1

[totaam]

securecrt is not open-source.

Please try to reproduce this bug with any widely available open-source application.

[cadem]

I used lubuntu-desktop (apt install lubuntu-desktop) in the docker, there is QTerminal in lubuntu-desktop, QTerminal has the same problem with securecrt. But I use ms-edge browser, ms vscode, but these 2 apps have no problems.

[totaam]

I've tried with qterminal on Fedora and I can copy text in and out of the terminal without any problems.

I wanted to try it on Ubuntu 24.04, but it failed to download a gazillion dependencies it needed to install qterminal.
My guess is that this is not an xpra bug.

Please try a better distro, like Fedora: https://github.com/Xpra-org/xpra/wiki/Platforms#platforms

[Simba98]

Hi all,

This is a known Qt5 bug, not related to Xpra.
Please discuss this with the developer of secureCRT and push them to update the Qt framework.

https://bugreports.qt.io/browse/QTBUG-65888

[cadem]

It is maybe a Qt5 bug. But I provide one more information about this problem. If I run the apps in remote desktop (xrdp) or derectly in X11, copy in the apps always works well, but copy is broken when resarting apps in xpra.

[Simba98]

It is maybe a Qt5 bug. But I provide one more information about this problem. If I run the apps in remote desktop (xrdp) or derectly in X11, copy in the apps always works well, but copy is broken when resarting apps in xpra.

Hi Cadem,

I noticed that you are running Xpra inside docker on Ubuntu.

Could you provide your Ubuntu version?
I found a similar case with Xpra in maybe another application.

My guessing is it is due to PID, an alternative guessing is a timestamp.

1. Everytime I reboot my system, clipboard with Xpra always work.
2. Restarting the application, docker, docker daemon would not solve the issue.
3. If the issue happens, use other X11 Server with the application still working.
4. Currently, I set system max_pid to 32767. Seems like it is working well.

I look forward to your reply.

[leo-b]

I also just experienced this issue when running KDE konsole in an Xpra session on a Rocky Linux 9 system (qt5-qtbase-5.15.9-10.el9_4.x86_64).

It only appears in new sessions and only in Xpra sessions:
I reconnected to an old xpra session running to the same remote host that was started back in December with konsole and X11 selection still working.
Also ssh'ing to that remote host with X11 forwarding and starting konsole from that session still works fine.

[leo-b]

Are you running Rocky 9 in VM / docker?

No docker or VM is involved.

You mentioned old sessions, do you mean you can workaround it by stop Xpra and restart Xpra?

I was talking about this xpra session that had been started back in December from a Windows box:

"C:\Program Files\Xpra\Xpra_cmd.exe" start ssh://[email protected]:1022/100 --start-child=konsole --exit-with-children=yes --audio=no --webcam=no --input-method=uim --keyboard-layout=de --ssh="plink"

I disconnected from that session and recently re-connected to verify that cipboard operations are still working.

On the other hand I just started a new session using the same commandline to display 101. In that new session, selections do not work anymore.

[totaam]

Probably fixed in 3e25ef4

[leo-b]

Probably fixed in 3e25ef4

Cood catch!
Just tried with 6.3-r37228 and could successfully copy this version string out of a KDE konsole window! :-)

Thanks!