Fix Clear Inheritance issues

[xuhuisheng]

• fixes: Clear Inheritance on Inherited Scene from base Scene with children with signals does not unlock signals until editor restart #91776 (comment)

There are so many problems when invoking Clear Inheritance

• After confirm 'Clear Inheritance? (No Undo)', the scene didn't do save really.
• There is no unsaved (*) mark on the title of editor.
• The children node of scene root cannot be renamed.
• The signal in the right side NodeDock is readonly.

There latest comment gives me a clue, that we can save scene and reload scene directly, then all of these issues resolved.

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Edit:

Follows KobeWi suggestion, don't save and reload scene, but update node in memory and mark unsaved.

[KoBeWi]

Is it possible to achieve the same without saving and reloading scene? If the scene is not saved, you can "undo" the change by reloading the scene, which is useful option.

You can clear scene's undo history and it will mark the scene as unsaved with no way of undo. Not sure about other problems, but it should be possible to fix them too.

[xuhuisheng]

Is it possible to achieve the same without saving and reloading scene? If the scene is not saved, you can "undo" the change by reloading the scene, which is useful option.

I can give it a try, but recreating the entire hierarchy, as reloading it from a file, would need lots of works.

[KoBeWi]

I think the problem is that update_tree() does not take effect for some reason (or it's updated wrong). The fix might be simply forcing a refresh. It should be possible without reload, and without lots of changes.

For a hacky solution, calling scene_tree->set_valid_types({}) will force full tree update, but I think a dedicated method would be better.

[xuhuisheng]

I think the problem is that update_tree() does not take effect for some reason (or it's updated wrong). The fix might be simply forcing a refresh. It should be possible without reload, and without lots of changes.

In my investigation, the "Clear Inheritance" operation is not complete. It only clean inheritated_state and emit an event, without clear all of it's children state. So after update_tree, we still get the old children's state.

godot/scene/main/node.cpp

Lines 2809 to 2813 in e825169

	void Node::set_scene_inherited_state(const Ref<SceneState> &p_state) {
	ERR_THREAD_GUARD
	data.inherited_state = p_state;
	_emit_editor_state_changed();
	}

And before "Clear Inheritance", there is only one node with a reference for an "ext_resource".

[ext_resource type="PackedScene" uid="uid://bowuloxmdkrly" path="res://prefab.tscn" id="1_by10c"]
[node name="PrefabChildToTest" instance=ExtResource("1_by10c")]

After "Clear Inheritance", we need create the real tree structure for the new scene.

[ext_resource type="Script" uid="uid://cdao4baykx3v" path="res://prefab.gd" id="1_3o2mv"]
[node name="PrefabChildToTest" type="Node2D"]
script = ExtResource("1_3o2mv")
[node name="Node2D" type="Node2D" parent="."]
[connection signal="draw" from="Node2D" to="." method="_on_node_2d_draw"]

I agree the current PR is not so good. I can do more digging to find a better solution.

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Edit:

scene_tree->set_valid_types({}) can resolve the left menu tree warning, but signal warning on Inspector is still.
I will keep digging.

[xuhuisheng]

@KoBeWi

I found check_and_update_scene() supports reload scene from memory. Please take a look when you have time.

BTW: There is a compilation error on windows platform. Looks like ret_nodes maybe unintiliazed on some situations. I don't know how to fix it, yet.

scene\resources\packed_scene.cpp:702:27: error: '*ret_nodes' may be used uninitialized [-Werror=maybe-uninitialized]
  702 |         return ret_nodes[0];

Maybe related this: #111771

[KoBeWi]

Some minor details left, but the implementation looks ok now.

[Repiteo]

Thanks!