Saved resource loses data when duplicated

[vvvvvvitor]

Tested versions

• Reproducible in: 4.2.2stable

System information

Godot v4.2.2.stable (15073afe3) - Freedesktop SDK 23.08 (Flatpak runtime) - Wayland - Vulkan (Forward+) - integrated Intel(R) UHD Graphics (ICL GT1) () - Intel(R) Core(TM) i3-1005G1 CPU @ 1.20GHz (4 Threads)

Issue description

When duplicating a saved resource, it's data seems to get lost.

The resource:

The code:

const ITEM_INDEX: Array[Item] = [
    preload("res://res/items/item_abyss_garden_key.tres")
]

# [...]

@export var icon: Texture = PLACEHOLDER_ICON
@export var name: String = "item"
@export var display_name: String = "Item"
@export_multiline var description: String = "The ultimate weapon!"

# [...]

static func get_item_from_index(item_id: int) -> Item:
    return ITEM_INDEX[item_id].duplicate()

When trying to get the values from the resource it returns the values that were predefined, in this case, if I try to get the "name" property, it'll return "item" instead of "garden_key".

When also trying to access the data of the resource directly (load("path").property) I get an error that says the property does not exist, even though it should

Invalid get index 'name' (on base: 'Resource').

Steps to reproduce

• Make a resource;
• Save it;
• Load and duplicate it;
• Try to access it's data.

Minimal reproduction project (MRP)

N/A

[Calinou]

• Related to https://github.com/godotengine/godot/issues/74918 (possible duplicate?).

[dalexeev]

This is due to cyclic dependencies and loading order. You want to have a constant in a class with instances of the same class, but this does not work as expected. If you move the constant to another class (ItemDB), it will work. Also you can use a static variable instead of constant and load() instead of preload(), then it will work in the same class (Item).

MRP: test-94242.zip

[vvvvvvitor]

This is due to cyclic dependencies and loading order. You want to have a constant in a class with instances of the same class, but this does not work as expected. If you move the constant to another class (ItemDB), it will work. Also you can use a static variable instead of constant and load() instead of preload(), then it will work in the same class (Item).

MRP: test-94242.zip

Ah, I see, should I close this issue then?

[dalexeev]

I think no. Even if we don't support this case, it should probably produce an error since constants are evaluated at compile time.