Area2D collision signal being received without having collision layer in mask

[p-brighenti]

Godot version:
v3.3.rc7.official

OS/device including version:
Windows 10 Home 20H2

Issue description:
Sorry about the title being confusing but I did not find a better way to summarize it in just a few words.

The issue I'm facing is that I have a node A which is a KinematicBody2d and has as a child an Area2D on layer 1 with, let's say, layer 2 and 4 in its mask.

The second node, B, is itself an Area2D which is on layer 3 and has layer 1 on its mask.

Both of these are monitorable and monitored.

Given this configuration I'm expecting that when A and B's areas collide, that B will receive a signal but not A given that it didn't have layer 3 on it's Area2D mask.

Currently A is receiving a body_entered signal when it collides with B's Area2D even though A's mask does not contain the layer B is in.

Is this the expected behaviour and is it up to the user to discard the event in it's callback by inspecting the body's argument collision_layer field?

Steps to reproduce:

1. Create a KinematicBody2D node with a Area2D as a child spanning over it.
2. Put the Area2D on layer 1 and no layer on it's mask. Make it both monitorable and monitoring
3. Attach a script to the KinematicBody2D node.
4. Connect the on_body_entered signal of Area2D
5. Create a Area2D node on layer 2 and with layer 1 on it's mask.
6. Make the KinematicBody2D node collide with the Area2D node
7. Verify that the signal callback is being called even though the KinematicBody2D's Area2D does not have layer 2 on it's mask

I'll make sure to update the issue with the minimal example tomorrow as I just don't have the time to do it today. My apologies.

[Calinou]

Duplicate of #7644 ?

[p-brighenti]

Duplicate of #7644 ?

Seems like it. If so, it's already being addressed in this PR #42268 .
Please consider it for 4.0, if you aren't considering it yet. I'll try to check if there's a proposal for this yet.
Thanks!