Instanced .blend/GLTF scenes lose all children after update until .tscn is reopened

[yahkr]

Tested versions

• Reproducible in: v4.3.beta2.official [b75f048]
• Reproducible in: v4.3.beta.custom_build [e57312d]
• Not reproducible in: v4.3.beta.custom_build [1e6b11d]
• Not reproducible in: v4.2.dev.custom_build [524e7ac]
• Not reproducible in: v4.2.2.stable.official [15073af]

System information

Godot v4.2.2.stable - Windows 10.0.22631 - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 4090 (NVIDIA; 32.0.15.5599) - Intel(R) Core(TM) i9-14900K (32 Threads)

Issue description

When making modifications to a .blend file, I noticed that upon reimport any child nodes that were previously there disappear until the scene is reloaded. From a cursory glance I believe the issue has to do with editor_node.cpp:6025 where the addition_list is empty

Steps to reproduce

Create new project
Instantiate an imported .blend scene
add a child node to it
save scene
modify the .blend file (anything to trigger re-import)
observe missing child node
close and re-open the scene
observe missing child node reappears.

Minimal reproduction project (MRP)

MRP.zip

[yahkr]

Removing the following condition fixes the issue.

godot/editor/editor_node.cpp

Line 4345 in e57312d

if (p_node->get_parent()->get_owner() != nullptr && p_node->get_parent()->get_owner() != p_edited_scene) {

#94020 resolves the issue of multiple re-imports not updating

[akien-mga]

CC @SaracenOne @Hilderin