Don't access Node3D/Node2D/Control global transform in reparent unless needed

[akien-mga]

Fixes #89002.

Marked as co-authored by @elementbound who found what the problem was. The solution needs to be slightly different to the one suggested in #89002, as the global transform needs to be fetched before reparenting, otherwise it won't work.

[Sauermann]

Changes are looking good.

An alternative solution for the referenced bug report would be to make Node3D::get_global_transform() accessible while not in the scene tree, just like it is possible with CanvasItem::get_global_transform(), so that 2D and 3D behave in the same way.

godot/scene/3d/node_3d.cpp

Lines 345 to 346 in df78c06

	Transform3D Node3D::get_global_transform() const {
	ERR_FAIL_COND_V(!is_inside_tree(), Transform3D());

[akien-mga]

An alternative solution for the referenced bug report would be to make Node3D::get_global_transform() accessible while not in the scene tree, just like it is possible with CanvasItem::get_global_transform(), so that 2D and 3D behave in the same way.

godot/scene/3d/node_3d.cpp

Lines 345 to 346 in df78c06

	Transform3D Node3D::get_global_transform() const {
	ERR_FAIL_COND_V(!is_inside_tree(), Transform3D());

This has significant implications though, see #70443 and #74659.

But more importantly, there is no reason to request the global transform if we're not going to use it when p_keep_global_transform = false, so this is the correct fix for #89002.

[Sauermann]

Thanks for the links to the other PRs - I was not aware of them.
I agree that this solution is correct .

Perhaps the same change should also be done for Node2D

godot/scene/2d/node_2d.cpp

Lines 144 to 151 in df78c06

	void Node2D::reparent(Node *p_parent, bool p_keep_global_transform) {
	ERR_THREAD_GUARD;
	Transform2D temp = get_global_transform();
	Node::reparent(p_parent);
	if (p_keep_global_transform) {
	set_global_transform(temp);
	}
	}

Edit: ... and Control::reparent

[akien-mga]

Perhaps the same change should also be done for Node2D

Edit: ... and Control::reparent

Good catch! Done.

[akien-mga]

Cherry-picked for 4.2.2.