Empty scenetree with unsaved scene

[ultsi]

Tested versions

• master with custom commits
• Godot v4.3.dev6

System information

Godot v4.3.dev6 - Ubuntu 20.04.6 LTS (Focal Fossa) - X11 - Vulkan (Forward+) - dedicated AMD Radeon RX 6600 (RADV NAVI23) () - AMD Ryzen 7 5800X 8-Core Processor (16 Threads)

Issue description

Empty scenetree on unsaved scene, when switching from non-initialized unsaved scene.

Steps to reproduce

1. Create new scene A
2. Add a 3D root node
3. Create new scene B, don't create a root node
4. Switch back to scene A [unsaved]

Scenetree should now be empty.

The empty scenetree can be fixed by switching to a saved scene and then back, then the unsaved scenetree appears again.

Minimal reproduction project (MRP)

N/A

[AThousandShips]

Can you replicate this on an unchanged branch? The commit you reference isn't part of the repo

[ultsi]

@AThousandShips yes was able to repro on Godot v4.3.dev6

[AThousandShips]

And on latest master as well? If you're able to test

[ultsi]

Yeah sure, let me recompile

[ultsi]

empty-scenetree-bug.mp4

Here's a simple repro video

[AThousandShips]

I can confirm on latest master

[matheusmdx]

This is a regression caused by #86605: