Clipboard sharing with wayland guest not working

[sledgehammer999]

Host: Windows 10
Guest: EndeavourOS (Arch based) with Plasma 6
Virtualbox version: 7.1.10
Guest additions version: 7.1.10

Problem description

Pasting from host to guest (wayland) -> works
Pasting from guest (x11) to host -> works
Pasting from guest (wayland) to host -> doesn't work

Pinpointing the problem

I did some debugging and the problem is that this check is always false:

virtualbox/src/VBox/Additions/x11/VBoxClient/wayland-helper-dcp.cpp

Line 831 in ecf221f

if (uFmt != g_DcpCtx.Session.clip.uFmt.defaults())

Small description of the codeflow:

1. vbcl_wayland_hlp_dcp_gh_clip_report_cb() waits on g_DcpCtx.Session.clip.uFmt and, if successful, it sets Session.clip.pvClipboardBuf and Session.clip.cbClipboardBuf (via a call to vbcl_wayland_hlp_dcp_receive_offer())
2. vbcl_wayland_hlp_dcp_gh_clip_read_join_cb() sets g_DcpCtx.Session.clip.uFmt and waits on Session.clip.pvClipboardBuf and Session.clip.cbClipboardBuf
3. vbcl_wayland_hlp_dcp_gh_clip_read_join_cb() is called after vbcl_wayland_hlp_dcp_gh_clip_report_cb()

This is a cyclic dependency that results in all those values being empty (defaulted) when read.

I think there is a logic problem here. vbcl_wayland_hlp_dcp_gh_clip_report_cb() does 2 actions that are meant to be distinct. It both reports to the host that clipboard data is available AND copies the clipboard data to internal buffers. The latter fails because it doesn't know which format the host expects at this point.
The data should be copied only after the host requests them.

[ArrayBolt3]

I'm encountering this with VirtualBox 7.2 with a Debian 13 guest with the labwc compositor.

Any known workarounds? Is there some way to get the guest utilities to connect to an Xwayland server within the guest instead?

[galitsyn-oracle]

Hi guys,

This is know issue with combination Windows host + Plasma guest. This is planned to be fixed. If switching to Gnome inside guest is an option -- that could be a workaround.

[ArrayBolt3]

@galitsyn-oracle Awesome. For what it's worth, I'm seeing this with a Plasma host and labwc guest, not sure if that's helpful. Thank you!

[shmerl]

This is know issue with combination Windows host + Plasma guest

I hit this issue, thanks for the heads up that you are working on it.