[WaylandBackend] Gamescope spams with icons sets, causing plasmashell to freeze

[OlegAckbar]

Is there an existing issue for this?

• I have searched the existing issues

Are you using any gamescope patches or a forked version of gamescope?

• The issue occurs on upstream gamescope without any modifications

Current Behavior

On KWin 6.3+ with xdg-toplevel-icon support Gamescope constantly sets application icon with frequency depending on framerate which causes plasmashell to freeze and then to crash when fd limit is reached.
So far I only experience this when playing games with Proton, native Linux applications seem to work.

Steps To Reproduce

1. Launch any Proton game
2. Try to interact with plasmashell

Hardware information

Processors: 16 × AMD Ryzen 7 9800X3D 8-Core Processor
Memory: 62.5 ГиБ of RAM
Graphics Processor: AMD Radeon RX 6700 XT
Manufacturer: ASUS

Software information

Operating System: Arch Linux 
KDE Plasma Version: 6.3.1
KDE Frameworks Version: 6.11.0
Qt Version: 6.8.2
Kernel Version: 6.13.3-2-cachyos (64-bit)
Graphics Platform: Wayland
[gamescope] [Info]  console: gamescope version 3.16.1-43-g0a09639d (gcc 14.2.1)

Which gamescope backends have the issue you are reporting?

• Wayland (default for nested gamescope)
• DRM (default for embedded gamescope, i.e. gamescope-session)
• SDL
• OpenVR

Logging, screenshots, or anything else

Relevant issue on kde buzilla: https://bugs.kde.org/show_bug.cgi?id=499917
Compressed log of gamescope running proton game with WAYLAND_DEBUG=1: https://bugs.kde.org/attachment.cgi?id=178691

[matte-schwartz]

Notably, both from the KDE issue comments and my own testing, mangoapp must be visible for some portion of time in order to trigger this issue.