Rocket.Chat Un-muting user not idempotent (resulting in unwanted state)

TL;DR

Muting & then un-muting one user has the side-effect, that he/she will be then able to send messages, even if the entire room gets set to read-only.

The root cause is that whilst un-muting the user, the name is removed from room.muted and added to room.unmuted. That's not idempotent.

Description:

The PR https://github.com/RocketChat/Rocket.Chat/pull/11311 fixed some issues with read-only & muted of a room. Unfortunately, this fix introduced a side-effect, that may not be intended.

Let's assume the following use case

Action	Effect	read-only	muted	unmuted
Chat `x` has participant `random-dude` (it's newly created)	Everybody can send messages	`false`	`[]`	`[]`
`random-dude` sends spam & therefore gets muted	Everybody but the `random-dude` can send messages	`false`	`['random-dude']`	`[]`
After stopping spamming, `random-dude` gets re-activated	Everybody can send messages	`false`	`[]`	`['random-dude']` ❗️
Now, the entire chat needs to be muted for some time -> moderator sets it to read-only	Nobody except the `random-dude` ❗️ can send messages	`true`	`[]`	`['random-dude']`

In my humble opinion, the marked (❗️) states are quiet odd. That means, once a user gets re-activated, the user is able to send messages even if the entire room gets muted. Even if the user gets kicked, its username remains in the room.unmuted array.

This is very error-prone, because the moderator doesn't see which users still are able to send messages.

Steps to reproduce:

Follow the mentioned use-case from above
For example, you may ...
- Log into the admin UI as administator
- Create a blank new room with a participant
- Open the e.g. Chrome developer tools & watch the WebSocket frames being send
- Use the administrator to follow the use-case

Expected behavior:

Muting and un-muting one user is idempotent. So a blank new user shall have the same muted-state as a 'muted and then unmuted user' (no record in neither muted and unmuted).

Actual behavior:

A 'muted and then unmuted user' still can send messages in a muted room.

Server Setup Information:

Version of Rocket.Chat Server: 1.3.2
Operating System: Linux
Deployment Method: docker
Number of Running Instances: 3
DB Replicaset Oplog: true
NodeJS Version: 8.11.4
MongoDB Version: 4.0.12

Sep 16 '19 12:09 winterstefan

Anybody can confirm that or give a hint how to work around this issue?

Oct 30 '19 16:10 winterstefan

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.