[Volume] Volume module breaks default sink

[donovanglover]

Describe the bug
Was trying out the volume module and looks like pipewire sinks get messed up when connecting new devices.

To Reproduce
Steps to reproduce the behavior:

1. Have an external monitor with audio output
2. Plug in headphones
3. Default sink changes to external monitor instead of headphones
4. Unplugging the headphones and killing ironbar results in the external monitor continuing to be the default sink

Expected behavior
Should maintain the same audio switching as when ironbar isn't being used

System information:

• Distro: NixOS unstable
• Compositor: Hyprland
• Ironbar version: 58190ab

Additional context
Causes pcieport 0000:00:08.1: PME: Spurious native interrupt! errors when connecting headphones

[JakeStanger]

Should maintain the same audio switching as when ironbar isn't being used

To confirm, the expected behaviour would be that it switches to the newly plugged in device right?

[donovanglover]

Ideally ironbar doesn't switch anything at all since I'm using switch-on-connect already

[JakeStanger]

I've not been able to replicate this using pipewire-pulse at all. In my own testing:

• On my desktop, (dis)connecting audio devices makes no difference. Audio playback continues where it was, the default remains the same and so ironbar's state also remains the same.
• On my laptop, monitor/headphones get treated as a single two-port device and switching is instant, but does not show in ironbar.

In neither scenario did I get any errors or other logs from the audio server or ironbar.

I'm suspicious that it could be switch-on-connect or another program/option causing problems. Ironbar does not ever try to change the default device unless you select an option from the popup dropdown, so I think it's less likely to be the cause, at least with a generic/default setup.

If you're able to confirm, and if not provide more information and more detailed repro steps I'll keep investigating.