Deserializing custom resource created through inspector results in parser error

[mihe]

Tested versions

• Reproducible in: 4.4.beta3
• Not reproducible in: 4.3.stable

System information

Godot v4.4.beta3 - Windows 11 (build 26100) - Multi-window, 3 monitors - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 4070 Laptop GPU (NVIDIA; 32.0.15.6636) - AMD Ryzen 9 7940HS w/ Radeon 780M Graphics (16 threads)

Issue description

When doing bytes_to_var_with_objects(var_to_bytes_with_objects(some_custom_resource)) where some_custom_resource was specifically created through the editor inspector, and not through something like MyResource.new(), you end up with a debugger break saying:

Parser Error: Class "MyResource" hides a global script class.

The exact same setup seemingly worked in 4.3-stable.

Steps to reproduce

1. Open the MRP.
2. Run the main scene.
3. Note error.

Minimal reproduction project (MRP)

resource-serialization-error.zip

[AThousandShips]

Can confirm, but happens for me in 4.3.stable and even in 4.2.2.stable, at least in my testing using the MRP

[mihe]

If you recreate that same setup in 4.3 (i.e. don't use the MRP project) the error won't show.

It might be related to the metadata/_custom_type_script property added to the sub_resource as of 4.4.

I was planning on providing a 4.3-stable MRP instead, but there's some other strange issue happening in the upgrade process (that I need to report as well) which forced me to provide a 4.4 repro instead.

[AThousandShips]

That makes sense when clarified!

With this added information I can pinpoint it as being introduced between dev3 and dev4

[mihe]

I just realized I could have just provided two MRPs in the first place, so here's one for 4.3, with no error: resource-serialization-error-4.3.zip

[AThousandShips]

Will bisect now that I know the span

[AThousandShips]

Bisected to:

• Enforce custom nodes to keep their original type #91341

CC @bjornmp @KoBeWi

Change was to close:

• Change Type with GDScript types / attached scripts does nothing. #37479
• Enforce that custom nodes/resources keep their original type (assigned script) godot-proposals#7905

---

Related issue:

• Deep copy custom resource created in 4.4dev4 or newer throws Parser Error: Class hides a global script class #100154

Which was supposed to be solved by:

• Fix Script metadata usage #101001

[KoBeWi]

bytes_to_var_with_objects will for some reason embed resources instead of referencing them. Custom type resources have hidden _custom_type_script metadata, which gets duplicated. The same would happen if you export a variable of type Script.

To fix it there needs to be an exception, similar to #100177.
Though a more comprehensive fix would be changing _custom_type_script to String. It would fix all duplication problems.

[ShrigmaDev]

@KoBeWi Hi, still running into this issue in 4.4 rc1. Tried deleting .godot folder, and the custom resource file itself and then recreating it, and the issue still persists... The project was created in 4.3 stable, is there anything I need to "reset" in order to fix this?

[KoBeWi]

It should be gone after you re-save the problematic scene. Check inside tscn if _custom_type_script meta is a String.

[ShrigmaDev]

It should be gone after you re-save the problematic scene. Check inside tscn if _custom_type_script meta is a String.

@KoBeWi My setup is slightly different but I've managed to create an MRP in #103271. The difference is the resource contains a PackedScene that defines a custom class, but also results in the same error as this one.