Fix cannot remove scene root when reload scene

[xuhuisheng]

• Fixes: [4.6 dev4] Moving scene file opened in another scene tries to free root scene node #112880
• Follow up: Fix crash on queue free scene node in editor #112401

Issue Description

When we move a instanced scene file cross different folders in FileSystemDock, we will call reload_scene() to reload both main.tscn and sub.tscn.

Currently, we call memdelete() to delete root node of scene immediately. It will be considered as an accidental deletion.

Because remove_scene() not only delete root node, but also delete whole scene, so it won't crash before.

Solution

We can change memdelete() to queue_free(), to free root node defer. In the current frame, we will delete relevant scene, then next frame won't consider root node cannot be deleted.

MRP

test-112880.zip

remove-root-node.webm