ImageTextureLayered does not persist its state

[Ithamar]

Godot version

4.0b1dev (commit c2f6664)

System information

Windows 10, Vulkan

Issue description

ImageTextureLayered and its subclasses do not save their "content" when asked by using ResourceSaver.save. No persistable properties are defined, so none are stored.

Steps to reproduce

The following code:

var i := Image.create(1, 1, false, Image.FORMAT_RGB8)
i.set_pixel(0,0, Color(1,0,0))
ResourceSaver.save(i, "res://image.tres")
var l := Texture2DArray.new()
l.create_from_images([ i ])
ResourceSaver.save(l, "res://layered.tres")

Results in layered.tres looking empty like this:

[gd_resource type="Texture2DArray" format=3]

[resource]

while image.tres shows the proper image was created (and saved):

[gd_resource type="Image" format=3]

[resource]
data = {
  "data": PackedByteArray(255, 0, 0),
  "format": "RGB8",
  "height": 1,
  "mipmaps": false,
  "width": 1
}

Minimal reproduction project

See code above.

[Ithamar]

I'd love to create a PR for this, but then I first have to understand how this is supposed to work. Since the whole TextureLayered code was completely reworked since 4.x, I have to idea what the (re)designer of this code had in mind for persistence. Any suggestions/hints would be greatly appreciated.

[Calinou]

4.0

Which alpha/beta version are you using? 4.0 isn't released in stable form yet.

[Ithamar]

4.0

Which alpha/beta version are you using? 4.0 isn't released in stable form yet.

Yeah sorry for not specifying that, it is a master branch from a day or so ago, commit c2f6664

[Calinou]

Related to #66192 and #54202 (likely due to the same cause).

[clayjohn]

Duplicate of #63025

As explained there, this:

var l := Texture2DArray.new()
l.create_from_images([ i ])

Should be:

var l = Texture2DArray.create_from_images([ i ])