Created attachment 112827 [details] Screen recording of the bug I have a pinned Virtualbox icon in my Icons-Only task Manager. When I click on it, Virtualbox launches but creates a new button for all of its windows. the new button has a different icon, depending on how may windows are open. Screen recording attached. The issue reminds me a bit of https://bugs.kde.org/show_bug.cgi?id=393787 This behavior is new to Kubuntu 18.04 with Virtualbox 5.2.10. I did not see it with the older version of Virtualbox bundled with Kubuntu 17.10. I was using the same Plasma version in both Ubuntu versions.
Created attachment 112828 [details] `xprop` output of Virtualbox's main window
Created attachment 112829 [details] `xprop` output of a Virtualbox VM window
Created attachment 112830 [details] virtualbox.desktop file
Upstream Ubuntu bug that I filed, in case there's any relevant information in there: https://bugs.launchpad.net/ubuntu/+source/virtualbox/+bug/1769417
$ (master) ps aux | grep -i virt nate 13657 0.0 0.1 178460 13612 ? S 07:13 0:00 /usr/lib/virtualbox/VBoxXPCOMIPCD nate 13662 0.2 0.3 972528 25240 ? Sl 07:13 0:01 /usr/lib/virtualbox/VBoxSVC --auto-shutdown nate 13682 29.4 15.4 4013988 1243356 ? Sl 07:13 2:59 /usr/lib/virtualbox/VirtualBox --comment Neon 2 --startvm 35dc1492-14b5-4be8-af1b-ea5b3dadf0f8 --no-startvm-errormsgbox nate 14157 0.0 0.0 16504 1068 pts/3 S+ 07:24 0:00 grep --color=auto -i virt
Thanks. This is an application bug. The WM_CLASS for the two windows is "VirtualBox Manager" and "VirtualBox Machine" respectively, which doesn't match the .desktop file name (virtualbox). The .desktop file also doesn't contain a StartupWMClass key that maps to either. The executables names in the process command line also don't map to the Exec= key of the .desktop file. This should be reported to VirtualBox upstream because it's just plain super broken. In the meantime, we can add hack-around mappings to taskmanagerrulesrc: https://phabricator.kde.org/D13060
https://www.virtualbox.org/ticket/12534 claims this should be fixed, but we can still add the mappings if people still use versions where this is a problem.
It's still the same in the VirtualBox packaged in Fedora 28. The alleged fix is six months old though and I don't know their release cycle.
Fixed with https://phabricator.kde.org/D13060