Some Qt-based applications open "another" icon under Gnome

[Dave Jones]

I'm unsure if this is a bug in the affected applications, or in the gnome dock itself. Under Ubuntu 23.10 (mantic) and 24.04 (noble), running Quassel, Veusz, or OpenSCAD from a pinned icon on the left bar results in the pinned icon appearing "idle" (not running), and a second icon appearing below those that are pinned which apparently represents the running instance.

Pressing the idle application icon (or pressing the Super+N shortcut for it) runs *another* instance of the application rather than switching to the running instance. The "extra" icon also cannot be pinned (and occasionally strange "copies" of it are left lying around if one tries to drag it to the pinned icon locations).

This may be because these are all Qt-based applications, but I also run KeepassXC (another Qt application) without such issues (other than unusual window borders and icons which appear on both applications), hence why I'm unsure this is an issue in these applications or in the gnome dock. I'll attach a screenshot demonstrating the issue.

[Daniel van Vugt (vanvugt)]

Sounds like https://github.com/micheleg/dash-to-dock/issues/651

[Dave Jones (waveform)]

Hmm, it certainly sounds similar in some aspects: if I click on the pinned icon for Quassel after it's already launched, it does launch another instance. However, I'm not using multiple monitors, or multiple workspaces, and currently it only occurs with Quassel. Firefox and terminal are unaffected.

[Dave Jones (waveform)]

This seems to be something to do with the version of the dash under mantic, and with the fact it's running under Wayland specifically. A similar issue came up on the Pi forums, and included an excellent minimal reproduction case (which I'll include here for simplicity). Notably, the issue does *not* occur (with either this reproduction case, or with quassel) under Xorg, only under a Wayland session:

~/.local/bin/stopwatch:

  #!/bin/bash
  echo "STOP"
  echo "Watch"
  read

~/.local/share/applications/stopwatch.desktop:

  [Desktop Entry]
  Version=1.0
  Type=Application
  Terminal=false
  Icon=StopWatch
  Name=StopWatch
  Exec=gnome-terminal --class=StopWatchTerminal -- /home/ubuntu/.local/bin/stopwatch
  StartupWMClass=StopWatchTerminal

Adjust the /home/ubuntu/ path as necessary. Pin the "StopWatch" application to the dash and launch it; under Xorg a dot appears next to the pinned application. Under Wayland, an additional "gnome-terminal-server" icon appears on the dash.

[Dave Jones (waveform)]

Oh, and the issue on the Pi forums is here: https://forums.raspberrypi.com/viewtopic.php?p=2167317