Area2D fires off "body entered" signal when scene is added back to scene tree

[golddotasksquestions]

Godot version: 3.2.1

OS/device including version: Win64

Issue description:

I have 3 scenes. A main Scene that has the a level as child and manages the adding and removing of levels, and two levels: a red level and a green level. The red_level gets removed and re-added every time, the green_level(s) gets instanced, added and then queued free.

The weird thing is whenever the red_level gets added back to the SceneTree, the Area2D detects the player body, even though I have set the position of the player body away from the Area before even removing the red_level scene.

This is a bit difficult to explain, best to look at the minimal project.

If makes no difference if the signal_next_level is call_deferred() or not.

func _on_AnimationPlayer_animation_finished(_anim_name):
	$player.position = Vector2(128, 256)
	stage_number += 1
	$Label.text = str("stage ", stage_number)
	$Area2D/ColorRect.modulate.a = 1.0
	call_deferred("emit_signal","signal_next_level")

What does make a difference though, is to yield timeout before the signal is emitted, but only if the timeout is long enough as user "sushi" on Discord figured out:

func _on_AnimationPlayer_animation_finished(_anim_name):
	$player.position = Vector2(128, 256)
	stage_number += 1
	$Label.text = str("stage ", stage_number)
	$Area2D/ColorRect.modulate.a = 1.0
	yield(get_tree().create_timer(0.1), "timeout") #0.01 would have no effect
	call_deferred("emit_signal","signal_next_level")

Possibly related issue:
#34085
also possibly related: #27441 (comment)

Steps to reproduce:
Walk the player into the area in the middle.

Minimal reproduction project:
Area2D_enter_on_remove_bug.zip

[Zireael07]

IIRC we had a related issue for 3D and the problem was the things are instanced at origin for a fraction of a second...

[golddotasksquestions]

@Zireael07 What do you mean by "things"? The Area too? This seems like really unclean and unreliable behavior to me. I would understand if it's in the same frame, but this I don't understand.

[t-karcher]

I'm pretty sure that's a duplicate of #14578 .

[Calinou]

Duplicate of #14578.