Wallpaper not being set in Wayland with Wayfire Compositor

Setting the wallpaper in Wayland with the Wayfire compositor is broken.

Issue Description

When using desktop settings dialog to set a wallpaper, the wallpaper does not change. It appears that the incorrect monitor name and hence xfconf property name is being used.

Steps to Reproduce Issue

1. Run Xfce using Wayfire as the compositor
2. Try to change the wallpaper through desktop settings
3. Wallpaper does not change

Expected Behavior

Wallpaper will be set properly if Wayfire is to be a supported compositor.

Additional Information

When monitoring xfconf when changing the wallpaper I see the following:

set: /backdrop/screen0/monitor0x0A78/workspace0/last-image (/home/ante/Pictures/Cyphercover.JPG)

However, if I use the following command it works:

xfconf-query -c xfce4-desktop -p /backdrop/screen0/monitoreDP-1/workspace0/last-image -s /home/ante/Pictures/Cyphercover.JPG

Note: I needed to create that property (monitoreDP-1) first as it was not automatically created.

Note2: This worked fine until you added support for the ext_workspace_manager_v1 protocol. I understand that Wayfire doesn't yet support this protocol and maybe this is why.

Environment & Versions

• OS distribution and version: Arch Linux
• Overall Xfce version: latest built from git master branch
• xfdesktop version (git hash if not a release): 4.19.6git- 238855f4
• Windowing system (X11/Wayland): Wayland
• Compositor and version (if Wayland): Wayfire (my wayfire.ini)
• GTK Theme: Adwaita
• Icon Theme: Qogir
• UI Scale Factor: 1.0