Server Side Wayland Decorations Resize on Non-resizable Applications

[tarek-y-ismail]

Steps to reproduce

1. Run a non-resizable application, making sure it uses its Wayland backend
2. Try dragging the corners or edges

Expected behavior: Decorations shouldn't resize. Additionally, the cursor shouldn't change.
Current behavior: The cursor indicates that edges and corners are resizable. And on dragging, decorations resize creating a blank area.

Note: This was confirmed on two SDL2 applications (neverputt, defendguin). It doesn't seem to occur on SDL3 examples (game-snake, camera-read-and-draw), so it might be SDL2 specific. Suggestions for/Reproductions on other non-SDL applications are welcome

[tarek-y-ismail]

After a bunch of investigation, it turns out that this was a bug with SDL2 not calling xdg_toplevel::set_{min,max}_size (see bug report at sway and SDL fix PR)

What's weird though is that GNOME somehow works around this? I'm not sure how or why..

[Saviq]

What's weird though is that GNOME somehow works around this? I'm not sure how or why.

Well, it's just that we treat no min/max size as unbounded, while GNOME treat it as if min/max was set to the preferred size? Or they've a quirk of some kind.

There's nothing in https://wayland.app/protocols/xdg-shell that I can see that would say which behaviour is appropriate - it's left to the compositor to decide, so IMO this bug can be closed on our side.