Arrays and Dictionaries with initial value are shared

[iiiCpu]

Once upon a time: #24134

Today: Godot Engine v3.2.3.stable.official

extends Node

class Wave:
	extends Node
	export var spawn_data = {}
	export var flag = false
	# # Uncomment to fix
	#func _init():
	#	spawn_data = {}

func reset_waves():
	if true:
		var wave = Wave.new()
		wave.name = "Wave_1"
		wave.spawn_data[ 50] = ['L1']
		wave.flag = true
		$Map.add_child(wave)
		wave.owner = $Map
		print(wave.flag, wave.spawn_data)
	if true:
		var wave = Wave.new()
		wave.name = "Wave_2"
		wave.spawn_data[111] = ['L1']
		$Map.add_child(wave)
		wave.owner = $Map
		print(wave.flag, wave.spawn_data)
	return

func _ready():
	reset_waves()

Expected:

True{50:[L1]}
False{111:[L1]}

Got:

True{50:[L1]}
False{111:[L1], 50:[L1]}

I expect initial value to be constant and all instances would have it's duplicate. Turns out I expect too much, as initial value is shared until 'duplicate' is called. Maybe we should add special keyword for this behavior? Like, I dunno, 'static'? Sounds legit to me.

[Calinou]

I didn't even know this syntax was allowed (in contrast to class Wave extends Node)…

class Wave:
	extends Node