Wallpaper portal permission issues

[sidt4]

Operating System

Debian Unstable

XDG Desktop Portal version

1.18

XDG Desktop Portal version (Other)

No response

Desktop Environment

GNOME

Desktop Environment (Other)

No response

Expected Behavior

1. Wallpaper portal permission dialog should be triggered when setting wallpaper, if app doesn't already have permissions.
2. When all permissions are removed, app should not be able to set wallpaper.

Current Behavior

From https://gitlab.gnome.org/bertob/nostalgia/-/issues/21:

1. Wallpaper portal permission dialog is not triggered when setting wallpaper, if app doesn't already have permissions.
2. When all permissions are removed, app can still set wallpaper.

The entire permission behavior is quite inconsistent. Refer comments in https://gitlab.gnome.org/bertob/nostalgia/-/issues/21 for more details.

Steps to Reproduce

Issue 1:

1. Wallpaper portal permission dialog is not triggered when setting wallpaper, if flatpak app doesn't already have permissions.

1. Install https://gitlab.gnome.org/bertob/nostalgia app from flatpak.
2. Try setting wallpaper.
3. Decline when access is requested in dialog.
4. Restart app.
5. Try setting wallpaper.
6. No access dialog is shown.

Issue 2:

2. When all permissions are removed, flatpak app can still set wallpaper.

1. Grant all access so setting wallpaper works correctly.
2. Remove all permissions as below.

   $ flatpak permission-set wallpaper wallpaper im.bernard.Nostalgia no
   $ flatpak permission-set background background im.bernard.Nostalgia no
   
   $ flatpak permission-show im.bernard.Nostalgia
   Table      Object     App                  Permissions Data
   background background im.bernard.Nostalgia no          0x00
   wallpaper  wallpaper  im.bernard.Nostalgia no          0x00
   

3. Try setting wallpaper.
4. It succeeds, when it should show an access dialog.

Anything else we should know?

No response