Move window to <left|right> monitor can also move desktop

Issue Description

When using the window manager keyboard shortcuts for "Move window to <left|right> monitor" I am able to move the selected window between my 2 monitors. However, if I have the Desktop Icons set to "File/launcher icons" or "Minimized application icons" and I select the desktop, making it the active "window", then I can move the desktop icons and rendered backdrop to the other monitors. There is an issue where the backdrop is not redrawn, so the icons are still visible on the monitor where they cannot be selected, but I think that the real solution is to prevent the user from using "Move window to X monitor" if the selected window is the desktop.

Steps to Reproduce Issue

  1. Set up more than one monitor
  2. Use the Desktop settings GUI to set the Icon type to either "File/launcher icons" or "Minimized application icons" in the Desktop Icons tab
  3. Set a keyboard binding for one or more of the "Move Window to <left|right|up|down> window manager actions in the Keyboard tab of the Window Manager settings GUI
  4. Click on the desktop
  5. Press the bound keyboard shortcut

Expected Behavior

When the desktop is selected, I expect the "Move window" actions to do nothing, because I do not consider the desktop to be a window.

Additional Information

Output of xfdesktop -V:

This is xfdesktop version 4.20.1, running on Xfce 4.20.
Built with GTK+ 3.24.51, linked with GTK+ 3.24.51.
Build options:
    Desktop Menu:        enabled
    Desktop Icons:       enabled
    Desktop File Icons:  enabled

Output of xfwm4 -V

	This is xfwm4 version 4.20.0 (revision unknown) for Xfce 4.20
	Released under the terms of the GNU General Public License.
	Compiled against GTK+-3.24.43, using GTK+-3.24.51.

	Build configuration and supported features:
	- Startup notification support:                 Yes
	- XSync support:                                Yes
	- Render support:                               Yes
	- Xrandr support:                               Yes
	- Xpresent support:                             Yes
	- X Input 2 support:                            No
	- Embedded compositor:                          Yes
	- Epoxy support:                                Yes

Environment & Versions

  • OS distribution and version: Manjaro Linux 26.0.3

  • Overall Xfce version: 4.20

  • xfdesktop version (git hash if not a release): 4.20.1

  • thunar version (if issue related to file/launcher icons):

  • Windowing system (X11/Wayland): X11

  • GTK Theme: Dracula

  • Icon Theme: Dracula

  • UI Scale Factor: 1

  • OS distribution and version: 26.0.4

  • Overall Xfce version: 4.20

  • xfdesktop version (git hash if not a release): 4.20.1

  • thunar version (if issue related to file/launcher icons): 4.20.7

  • Windowing system (X11/Wayland): X11

  • Compositor and version (if Wayland):

  • GTK Theme: Dracula

  • Icon Theme: Dracula

  • UI Scale Factor: 1