Resource.duplicate(true) doesn't duplicate subresources in Array or Dictionary

[limbonaut]

Related to #4.

Because of this behavior, set_point_array(make_unique=true) is not working as expected. SS2D_Point resources are not duplicated, when SS2D_Point_Array is duplicated. Only dictionary that holds them is duplicated, preserving SS2D_Point references that are stored as dictionary values.

This is a part of deeper design issue involving copy-pasting of shapes, meta shapes and sharing/not sharing shape properties. At this moment, copy-paste of a shape produces a shape copy in a state that is not easily fixable via UI.

[mphe]

So, the engine internal implementation of Resource does not pass the deep copy parameter of duplicate to the duplicate call of its array/dictionary properties?
That sounds like an engine bug.

[limbonaut]

And I found the root of the problem:
https://github.com/godotengine/godot/blob/fc7adaab7b3856a7831d402ea2bbb27efe7b7d8a/core/variant/variant_setget.cpp#L1889-L1900

So, the engine internal implementation of Resource does not pass the deep copy parameter of duplicate to the duplicate call of its array/dictionary properties?

It passes, they don't act on it as expected it seems. Only non-Object Variant values are deep-copied.

[mphe]

What the hell. I found a related issue here: godotengine/godot#37162. The documentation could really be more clear on this.

Alright, so we need to add duplicate back, at least in some classes, under a different name to not override the internal duplicate, manually deep copy affected properties, and then adapt other code to use the custom duplicate function.