Thread message's when mentioned @all doesn't appear correctly on room list

[Pamelowski]

Description:

Thread messages in rooms are not being marked as unread and no unread badge/counter is shown in the room list sidebar.

When a member of a room sends a message inside a thread, other room members do not receive any unread indicator — the room does not display the unread badge (the circle with a message count number) in the left sidebar. This affects both regular thread messages ( expected ) and @all mentions used within threads.

specific scenario:

@all mention inside a thread (where no other users were previously involved in the thread): A desktop notification is triggered, and the room moves to the top of the sidebar list, but the unread badge (circle with message count) is still not displayed.

---

Steps to reproduce:

1. Create a room with at least 3 members (User A, User B, User C).
2. Log in as User A and send a message in the room.
3. Log in as User B and reply to that message with ''@ALL"
4. Log in as User C (who has not opened the thread).
5. Observe the left sidebar room list.

---

Expected behavior:

When a thread reply is posted — especially one that includes an @all mention — all room members should:

• Receive a system/browser/desktop notification,
• See the room jump to the top of the unread list,
• See an unread badge (circle with message count) on the room in the sidebar.

---

Actual behavior:

• For plain thread replies: no notification, no unread badge, no counter shown in sidebar.
• For @all inside a thread: desktop notification appears and room moves to top of list, but the unread badge and message counter are missing.

This issue occurs on both the Desktop App and in all tested browsers (Opera, Chrome, Firefox).

---

Server Setup Information:

• Version of Rocket.Chat Server: 8.2
• License Type: Community
• Number of Users: 50
• Operating System: Ubuntu 24.04
• Deployment Method: * tar *
• Number of Running Instances: * 1 *
• DB Replicaset Oplog: * Enabled (rs0) *
• NodeJS Version: * v12.22.1 *
• MongoDB Version: * 8.0.19 *

Note: This issue was also present in previous versions of Rocket.Chat server.

---

Client Setup Information:

• Desktop App Version: 4.12 (Windows 11)
• Browsers tested: Opera, Chrome (latest), Firefox (latest)
• Operating System: Windows 11

---

Additional context:

This is a regression or persistent bug across multiple server versions. The core issue seems to be that thread messages — and even @all mentions within threads — do not properly trigger the unread state in the room sidebar for users who are room members but not active thread participants.

---

[metaloozee]

@Pamelowski

For normal messages in a room, the app uses updateUsersSubscriptions() method which increments the unread count and sets alert for all affected users. This is entirely skipped for thread messages by design. When replying in a thread, it follows a different approach.

In short: Thread @all and @here replies are only marking thread followers as unread, so non-followers are unaffected and hence, the room list badge never appears.

I am working on a fix where when a thread reply contains @all or @here, it collects all room members (excluding the sender), marks the thread as unread for every member by adding the thread id to tunread. I suppose, this ensures the sidebar badge appears for everyone in the room, not just the people already following the thread.

[metaloozee]

This design choice can also be by-choice. Hence, before submitting a PR I would want to receive feedback from the maintainers regarding the issue.

[dewani12]

hey,

i think there can be 2 approaches:

1. local scope: @all tag used in a message inside a thread should be notified to users active in a thread, notify using thread item in menu at top right inside a channel & channel in the left sidebar both shows unread badge (with a unread message count number).(no non active user triggered).
   Screen shot:

2. global scope: trigger everyone in the channel (also include non active member) and notify using thread item in menu at top right inside a channel & channel in the left sidebar both shows unread badge (with a unread message count number).

[metaloozee]

The local first approach seems more logical. Only the users participating in a thread will be mentioned instead of everyone in the room.