Consider sending the first wl_surface.preferred_buffer_scale = 1

[YaLTeR]

While wl_surface.preferred_buffer_scale is defined to default to 1, GNOME sends the initial preferred_buffer_scale(1), so clients may start to rely on it.

For example, Kitty was relying on this: kovidgoyal/kitty#8236 Though admittedly, it was to work around suboptimal behavior in other compositors, and it's just been changed in Kitty in a way that shouldn't affect Smithay any more.

In any case, it should be a simple change in Smithay, and it's just one event at initial configure, so maybe it's best to send it. The relevant code:

smithay/src/wayland/compositor/mod.rs

Lines 413 to 422 in 953959e

	// NOTE we insert default for checks below to work properly.
	let mut storage = data
	.data_map
	.get_or_insert(|| RefCell::new(SuggestedSurfaceState::default()))
	.borrow_mut();
	if storage.scale != scale {
	surface.preferred_buffer_scale(scale);
	storage.scale = scale;
	}

Note that GNOME does not send the initial preferred_buffer_transform if it's Normal.

[kchibisov]

You only mention the wl_surface v6, but you should account for fractional as well, which is other place.

[YaLTeR]

Fractional already sends initial scale = 1, at least on niri

[kchibisov]

Hm, indeed, I guess the issue is that identifying when you'd need to send it initially, and I think it's when you assign the scale.

[Drakulix]

I guess wouldn't cause any harm to send an initial scale value, even if it is 1, as long as downstream has the option to send a different value for the initial configure. PRs welcome.