On wayland the window icon is not set correctly

[bulldog98]

System Information

MultiMC version: git commit 66b0ed2

Operating System: Linux with Wayland

Summary of the issue or suggestion:
If you start MultiMc on Linux with wayland, the window will have the default wayland icon as icon

What should happen:
The window should have the MultiMc icon as icon

Steps to reproduce the issue (Add more if needed):

1. Compile MultiMc

2. Start it on wayland

3. Look for the icon of the window

Suspected cause:
As described in https://blog.martin-graesslin.com/blog/2015/07/porting-qt-applications-to-wayland/ the problem is that a wayland compositor (kinda equivalent to window manager) uses desktop files to get the icon of a window.

Logs/Screenshots:

Additional Info:

[peterix]

Cool. Then wayland is broken.

[L-as]

What compositor are you using? There is no standard protocol to set icons IIRC, though I may be wrong.

[bulldog98]

I'm using kwin

[31j]

The issue can be replicated on Gnome as well (3.x under wayland and 40.x), [using Mutter]

What compositor are you using? There is no standard protocol to set icons IIRC, though I may be wrong.

Don't most implementations have the compositor pull icons from .desktop files? Can't comment for Mir, Sway, Weston or anything more exotic but at least for kwin / Mutter this is what I think happens.

[redcathode]

For a quick and dirty fix, rename the multimc desktop file from multimc.desktop to org.multimc.multimc.desktop

[leo60228]

I believe QGuiApplication::setDesktopFileName is the intended solution to this issue.

[peterix]

That does not exist in Qt 5.4, which MultiMC targets.

[leo60228]

That's fair, but it might be getting time to bump that requirement (5.4's been EOL for nearly 5 years now). That's a separate concern from this issue, though.