Error when generating multiple Godot scenes from one GLTFState

[aaronfranke]

Godot version

Latest master 4.2.dev 5444afa

System information

macOS 13.4.1

Issue description

The GLTF code has the file parsing and node generation steps split up. This should allow generating multiple Godot scenes from the same imported GLTF file. However, this does not currently work as expected. Example GDScript code:

func _ready() -> void:
	var gltf_document := GLTFDocument.new()
	var gltf_state := GLTFState.new()
	gltf_document.append_from_file("res://mannequiny-0.3.0.glb", gltf_state)
	var scene_node: Node = gltf_document.generate_scene(gltf_state)
	add_child(scene_node)
	scene_node = gltf_document.generate_scene(gltf_state)
	add_child(scene_node)

Basically, the Godot node generation should all be happening in the orange circle, but the current code has a problem where some of it is happening in the red circle:

Steps to reproduce

Open the minimal reproduction project and hit the play button. The project contains the above code.

With the current master: Godot crashes.

With only #80272: The second scene is missing a skeleton, and errors are spammed in the console.

With both #80272 and #80831: Both scenes have a skeleton (the correct behavior).

Minimal reproduction project

GLTFGenerateMultipleScenes.zip