find_child method doesn't find a child by name after changing it's parent

[Voaz]

Tested versions

reproducible in v4.2.2.stable.arch_linux

System information

Godot v4.2.2.stable unknown - Manjaro Linux #1 SMP PREEMPT_DYNAMIC Mon Jun 10 09:50:04 UTC 2024 - X11 - GLES3 (Compatibility) - AMD Radeon RX 7600 (radeonsi, navi33, LLVM 17.0.6, DRM 3.57, 6.9.3-3-MANJARO) () - AMD Ryzen 5 5600G with Radeon Graphics (12 Threads)

Issue description

when I print print_debug(player.get_children())
I see
[Head:<Node3D#30349984988>, CollisionShape3D:<CollisionShape3D#30400316699>]
but player.find_child("Head") returns null

Steps to reproduce

Node3D [Car]

• Camera3D

CharacterBody3D [Player]

• Node3D [Head]
• • Camera3D

move the CharacterBody3D to the Car (Player.get_parent().remove_child(Player) and Car.add_child(Player))
and set the active camera to Cars camera (not required)
then move Player back to root
try to find Head Player.find_child("Head") -> result is null.

Minimal reproduction project (MRP)

later

[AThousandShips]

Does it work with find_children("Head", "", true, false)?

[Voaz]

find_child("Head", "", true, false) says too many arguments, but it works like this (I suppose that what you meant to check): find_child("Head", true, false)

[AThousandShips]

Meant find_children my bad, but yes find_child("Head", true, false)

[Voaz]

got it, I checked also other variants:
find_child("Head", false, false) - works
find_child("Head", true, false) - works
find_child("Head", true, true) - doesn't
find_children("Head", "", false, true) - doesn't
find_children("Head", "", false, false) - works

[AThousandShips]

Then it's expected, you haven't set the owner, the last argument filters only for owned nodes:

If owned is true, only descendants with a valid owner node are checked.

[Voaz]

I see, thank you very much @AThousandShips !
IMO: I have to say that it's counterintuitive. I never before was setting owner and it's unclear why it's true by default in find_child.
it is very contradicting when you clearly see it in the tree but find_child gives you null result nevertheless it IS still a child and it is in the tree but the owner is not set...
if so player.get_children() should also give null result and have a owned argument otherwise it's misleading.

[AThousandShips]

Please open a proposal for that, this is not a bug, but the argument can't be changed to false by default without breaking compatibility so won't happen in 4.x I'd say

[Voaz]

I believe needs to be reopen because the behavior is inconsistent. it's not only about find_child but the whole chain of actions.
if I do the same find_child before changing it's parent - it works. but if I change the parent and then return back to original parent - it doesn't work.

[AThousandShips]

The owner is reset on changing the parent, everything works as designed, so it's something to discuss as a proposal for changing behaviour, not something that's broken or a bug, see here, if you want the owner to be preserved use reparent instead