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

[agshultz]

Tested versions

• Reproducible in 4.4dev6, 4.3 stable, 4.2.2 stable, 4.0 stable, did not test older version

System information

Godot v4.4.dev6 - Windows 10.0.22631 - Multi-window, 1 monitor - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 4070 Laptop GPU (NVIDIA; 32.0.15.6636) - 13th Gen Intel(R) Core(TM) i9-13900H (20 threads)

Issue description

Deep copying a custom resource ( cust_resource.duplicate(true) ) created in 4.4dev4 or newer results in Parser Error: Class "CustomResource" hides a global script class.

The same project and custom resource instance created in 4.4dev3 or older does not result in the error. Seems to be a regression related to #72119 fixed in #71142

Steps to reproduce

As in MRP:
Create new custom resource with class_name (completely empty class is fine)
Perform a .duplicate(true) on custom resource

Minimal reproduction project (MRP)

mrp_resource_duplicate.zip

[HolonProduction]

For some reason some editor only metadata gets serialized to the file: metadata/_custom_type_script, this contains the same script as the script property. This metadata is not marked as never duplicate so it will result in the attempt to duplicate the script.

[dalexeev]

• See Enforce custom nodes to keep their original type #91341.

CC @bjornmp @KoBeWi

[MrDobby92]

Does anyone know a workaround for this?

[HolonProduction]

You can manually edit the resource file using a text editor. Remove the metadata/_custom_type_script property, as long as you don't re-save the scene it should keep working.