ItemList disabled items trigger selection and activation signals on mouse

[YuriSizov]

Godot version:
3.2.1.stable

OS/device including version:
Windows 10

Issue description:
According to ItemList documentation setting an item disabled means:

Disabled items cannot be selected and do not trigger activation signals (when double-clicking or pressing Enter).

However, when clicked with mouse, they can still trigger item_selected and item_activated signals. Visually such items appear disabled and they cannot be selected with keyboard either: pressing arrow keys does not move the selection if the next item is disabled. But on clicks they do react.

Selection itself never changes, and signals can be filtered with is_item_disabled. So, this may be an error in classref. The only similar issue I have found was related to 2.1 (#5683), which resulted in fixing item behaviour.

Steps to reproduce:

1. Create a UI scene with an ItemList node.
2. Create a similar script to fill ItemList with items and disable one:

extends Control

onready var item_list : ItemList = $ItemList

func _ready() -> void:
	item_list.clear()
	item_list.add_item("test item 1")
	item_list.add_item("test item 2")
	item_list.add_item("test item 3")
	item_list.add_item("test item 4")
	item_list.add_item("test item 5")
	
	item_list.set_item_disabled(2, true)
	
	item_list.connect("item_activated", self, "_on_item_activated")
	item_list.connect("item_selected", self, "_on_item_selected")

func _on_item_activated(item_index : int) -> void:
	print("item #" + str(item_index) + " was activated")

func _on_item_selected(item_index : int) -> void:
	print("item #" + str(item_index) + " was selected")

3. Run the project, clicking on the disabled item still produces prints:

item #2 was selected
item #2 was activated

Minimal reproduction project:
bug-itemlist-disabled-activation.zip

[KoBeWi]

Fixed by #60123

[goblinJoel]

Any chance of getting the fix in 3.x as well?

[TaphouseGames]

Seems like this is an issue again in godot 3.5

[KoBeWi]

The fix was never backported, it's only in 4.0.