--target-colorspace-hint and --idle=yes won't work correctly together

Important Information

Provide following Information:

• mpv version: mpv 0.34.0-292-g3458651010
• Windows Version: Windows 10 21H2
• Source of the mpv binary: Windows builds by shinchiro
• GPU: RTX3050

Reproduction steps

Run mpv.com HDR.mkv --vo=gpu-next --target-colorspace-hint=yes --gpu-api=vulkan --idle=yes. Your TV will correctly switch to HDR but after the file ends it will stay in HDR, whereas the same line with --idle=no will set the TV back to SDR after the file is finished. When opening an SDR file after that (with --idle=yes) the TV goes back to SDR and stays there after the SDR file is over.

Expected behavior

Switch back to SDR, when the HDR file ends with --idle=yes

Actual behavior

TV stays in HDR after the HDR file ends with --idle=yes

Log file

I´m sorry. I´ve not pulled the logs from testing. No idea if they are really needed as the issue is easily reproducible with the mentioned command line.

Sample files

Any HDR file will trigger this. (I tried it with the "The World in HDR" mkv file from the Kodi samples)

Start by reproducing the issue with the supplied mpv.com command using an HDR file and --idle=yes, then compare the behavior with --idle=no and with an SDR file. Trace the gpu-next HDR/colorspace transition when playback ends; done means the display returns to SDR after the HDR file finishes while idle mode remains enabled.