Godot4.4-dev5: `ClassDB` provides classes AnimationNodeStartState and AnimationNodeEndStatewhere which are not registered

[MikeSchulze]

Tested versions

v4.4.dev5.mono.official [9e60984]

System information

all

Issue description

I iterate over all classes provided by ClassDB for testing. Using ClassDB:get_class_list()
With Godot4.4.dev5 there is now “AnimationNodeStartState”, “AnimationNodeEndState” there are not documented and cannot be instantiated.

Steps to reproduce

Can be verified by

extends Node

func _ready() -> void:
	prints("AnimationNodeStartState class_exists:", ClassDB.class_exists("AnimationNodeStartState"))
	prints("AnimationNodeStartState can_instantiate:", ClassDB.can_instantiate("AnimationNodeStartState"))

        # compile error
	AnimationNodeStartState.new()

output:

AnimationNodeStartState class_exists: true
AnimationNodeStartState can_instantiate: true

errors:

 res://test.gd:7 - Parse Error: Native class GDScriptNativeClass used in script doesn't exist or isn't exposed.
  res://test.gd:7 - Parse Error: Static function "new()" not found in base "GDScriptNativeClass".

Minimal reproduction project (MRP)

n/a

[akien-mga]

CC @TokageItLab @RandomShaper, see also #98963 which registered those classes as internal.

[TokageItLab]

They are "currently" only used to make decisions to prevent editing, so I believe they can actually be replaced by the AnimationNode. However, they will need to be exposed again in the future when we allow additional ports (see also #88878 (comment)), but until then they are not necessary.

[dsnopek]

output:

AnimationNodeStartState class_exists: true
AnimationNodeStartState can_instantiate: true

I feel like this indicates a bug somewhere. These classes are registered via GDREGISTER_INTERNAL_CLASS(), which I would have expected to make can_instantiate() return false

UPDATE: Did a little more poking around!

Internally, we use ClassDB::_can_instantiate() to check if we really can instantiate a class - this should return true for an internal class, because we need to be able to instantiate one for internal classes to work from GDExtension.

But, for the public ClassDB::can_instantiate() it would make logical sense to return false - but I'm not sure if that would maybe break something else somewhere? If it would, then maybe we need to add a ClassDB::is_exposed() function so its possible to check if a registered class is internal?