Fix Camera2D is enabled when dragging scene files to the CanvasItemEditor

[WhalesState]

Fixes: #87704

[KoBeWi]

This bug potentially affects all nodes that rely on is_part_of_edited_scene() and can be part of a drag preview, so the change should be done in is_part_of_edited_scene() I think.

[WhalesState]

This bug potentially affects all nodes that rely on is_part_of_edited_scene() and can be part of a drag preview, so the change should be done in is_part_of_edited_scene() I think.

Yes, but the main issue is that the dragged scenes is instantiated and is added to the editor's root while dragging, this behavior will result in more issues like running the tool scripts while dragging, especially if it's a heavy scene.

is_part_of_edited_scene() works as expected, but while dragging it will return false because a scene instance will be added to the editor's root before dropping it to the edited scene.

I have tried to stop the dragged scene from proccessing, but it didn't work as expected, maybe we can add an internal preview node to the edited scene and we prevent it from being saved instead of adding it to the editor's root.

[KoBeWi]

Which is why I suggested that the change can be done in is_part_of_edited_scene(), so that it checks whether the node is under scene root viewport, not the scene itself. While that would make it technically incorrect, the only nodes under the root viewport are the scene and the drag previews, so it shouldn't have any negative impact.

[WhalesState]

Is it fine to add this get_tree()->get_edited_scene_root()->get_viewport() == get_viewport() ?

bool Node::is_part_of_edited_scene() const {
	return Engine::get_singleton()->is_editor_hint() && is_inside_tree() && get_tree()->get_edited_scene_root() && 
			(get_tree()->get_edited_scene_root() == this || get_tree()->get_edited_scene_root()->get_viewport() == get_viewport() || get_tree()->get_edited_scene_root()->is_ancestor_of(this));
}

[KoBeWi]

It reminded me of this old issue: #39221

The best condition would be: Engine::get_singleton()->is_editor_hint() && is_inside_tree() && EditorNode::get_singleton()->get_scene_root()->is_ancestor_of(this), but since this is Node code, the EditorNode can't be used. The problem with your check is that if a scene is empty, the issue will still be happening. Though it's still less likely to appear.

I'd suggest this for now:

bool Node::is_part_of_edited_scene() const {
	return Engine::get_singleton()->is_editor_hint() && is_inside_tree() && get_tree()->get_edited_scene_root() && 
			get_tree()->get_edited_scene_root()->get_parent()->is_ancestor_of(this);
}

[akien-mga]

Thanks!