Enabling use_xr breaks OmniLights in gl_compatibility

[Malcolmnixon]

Godot version

4.1.2-rc.1

System information

Windows 11, gl_compatibility, NVidia RTX 3070 TI

Issue description

The Godot XR Dungeon Demo project has a single OmnlLight3D for the player:

When the renderer is switched over to gl_compatibility the OmniLight3D stops working:

This was tracked down to get_viewport().use_xr = true. When this is performed, the OmniLight3D fails on both the PC and the headset. If it's commented out then the PC renders correctly and no output goes to the headset.

Steps to reproduce

This can be replicated by:

• Check out https://github.com/Malcolmnixon/godot-xr-dungeon-template
• Open with Godot 4.1.2
• Switch renderer over to gl_compatibility
• To go directly to broken scene:
  • Set game/zones/level1/level1.tscn as main scene
  • Add Godot XR Tools StartXR node
• Run project on PC and observe failure
• Comment out get_viewport().use_xr = true in the Godot XR Tools start_xr.gd script
• Run project on PC and observe light working on PC (but no headset output)

Minimal reproduction project

A smaller demo project can be constructed if needed; however it still requires enough machinery to start an XR instance in the headset, so it wouldn't be "small".

[dsnopek]

This appears to be fixed by PR #92186 in my testing