Scripts not added retroactively to instanced inherited scenes open in editor

[Edmanbosch]

bugsquad edit: reproduction steps which were used to confirm the issue are here: #10156 (comment)

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Operating system or device - Godot version:
OS: Windows
Godot Version: 3.0 Alpha Build 1

Issue description:
I have found a problem where when I add a script to a scene, all nodes that instance that scene don't get the script.

Steps to reproduce:

1. Make a scene that you will instance.
2. Instance that scene into the scene your game will run.
3. Add a script to the original scene.

[kubecz3k]

edit: this comment is totally useless
I believe the way how it's working currently is a design decision. Usually you should create companion script at the time of creating new scene, so when it will be added to the scene, the information about this script and related node will be saved inside scene file (the one which is parent of instanced scene).
The problem is, it would be hard to behave properly in each scenario if we would just assume that all instanced scenes should have the same script which is defined in the source file. We wanted to have ability to change scripts locally for instanced scenes, or remove scripts entirely if developer decides it's what he need.

[kubecz3k]

Ok I was wrong, @akien-mga help me realize it's a real bug which was not present in 2.x. Sorry for being smart-ass!

[kubecz3k]

I was trying to reproduce, but I was unable to do this with provided reproduction steps.

But after adding inheritance to the mix, the issue is reproducible for me:

1. Create World scene, save it.
2. Create Base scene, save it.
3. Create Child scene which is extending Base, save it.
4. Add Childto the World, save
5. Add script to the root node of Base scene, save it.
6. Check Child scene and observe that script is present.
7. Check World scene and observe that script is not attached to instanced Child node.

I used db7f491 build

[akien-mga]

I can still reproduce this in the current master branch (52165fa). There's a workaround though, as when following the above steps to reproduce, the Child node in the World scene will indeed lack the new script, but its script property will be shown as modified with a button to revert to the base value.

As such, it's not necessarily critical to fix for 3.0, so moving to 3.1 milestone.

[Piet-G]

Could not reproduce this on master 451e5fd.

[akien-mga]

I could still reproduce on master using the exact steps outlined in #10156 (comment).

Reopening the World scene fixes it though, it's only a temporary issue.

[akien-mga]

It's only a cosmetic issue as things do work once you reload the scene/run the game, so not blocking for the 3.1 milestone.

[Piet-G]

Oh yeah I reloaded the scene, that makes sense.

[KoBeWi]

I can't seem to reproduce it in 3.1.1

[akien-mga]

Still reproducible for me in master (a46b8e1), again following the precise steps outlined in #10156 (comment)

If you close World and reopen it after having changed the Base scene, the bug doesn't appear. It's strictly a bug with reloading the instanced inherited scene to take changes of its base scene into account.

[KoBeWi]

Ah, I was adding the script to Child scene. Nevermind then.

[Anutrix]

As far as I can understand, refresh/fix should happen somewhere in

godot/editor/scene_tree_dock.cpp

Line 162 in 3c133ae

void SceneTreeDock::_perform_instance_scenes(const Vector<String> &p_files, Node *parent, int p_pos) {

Am I wrong?

[KoBeWi]

Sooo I tried to reproduce it in 3.2.3 rc4 and reloading the scene no longer helps. Here's what I get in the tscn file:

[node name="Child" parent="." instance=ExtResource( 1 )]
script = null

So it got worse.