(Duplicated)wayland: do not require sRGB transfer support for HDR

[drbermejor]

Summary

This relaxes the Wayland color-management capability check by no longer requiring WP_COLOR_MANAGER_V1_TRANSFER_FUNCTION_SRGB before exposing HDR support to clients.

Motivation

On KDE Plasma/KWin 6.7, nested gamescope sees HDR enabled on the host compositor, but refuses to expose HDR formats to clients because the sRGB transfer function is not advertised in the way gamescope currently expects.

Before this change, gamescope reports:

cv_hdr_enabled: true
bExposeHDRSupport: false
server hdr output enabled: false
hdr formats exposed to client: false

After this change, on the same system, gamescope reports:

cv_hdr_enabled: true
bExposeHDRSupport: true
server hdr output enabled: true
hdr formats exposed to client: true
colorspace: VK_COLOR_SPACE_HDR10_ST2084_EXT

Tested Setup

System:

CachyOS
KDE Plasma/KWin 6.7.0
Wayland session
AMD Radeon RX 9070 XT, RADV
DisplayPort HDR display at 2560x1440@180 Hz
HDR enabled in KDE display settings

Game/application tested:

Dune Awakening / DuneSandbox-Win64-Shipping.exe
Steam app id: 1172710

Launch options used:

PROTON_ENABLE_HDR=1 ENABLE_HDR_WSI=1 ENABLE_GAMESCOPE_WSI=1 DXVK_HDR=1 gamescope -f -W 2560 -H 1440 -w 2560 -h 1440 -r 180 --hdr-enabled --adaptive-sync -- %command%

Also tested with the same gamescope launch path using both:

Proton Experimental
proton-cachyos-slr / cachyos-11.0-20260601-slr

With both Proton builds, after this patch gamescope exposes HDR successfully:

server hdr output enabled:     true
hdr formats exposed to client: true
colorspace: VK_COLOR_SPACE_HDR10_ST2084_EXT

The game log also keeps HDR enabled instead of reporting unsupported HDR output:

r.HDR.EnableHDROutput ... Value remains '1'

Before this patch, the same game and launch options reached gamescope, but HDR was not exposed to the client:

server hdr output enabled:     false
hdr formats exposed to client: false
colorspace: VK_COLOR_SPACE_SRGB_NONLINEAR_KHR

Related

Refs: #2221

[matte-schwartz]

we have #2222 which looks to be the exact same fix

[drbermejor]

Closing this as duplicate of #2222. I initially opened it because applying #2222 locally did not solve the issue in my environment, but after comparing the final diff both PRs are equivalent. The useful part here is the runtime validation: this change exposes HDR correctly on KDE Plasma/KWin 6.7 with gamescope under CachyOS/RX 9070 XT.