Recent fixes for threaded receipts expose existing unread bugs with reactions in threads

[andybalaam]

These two fixes:

• Send correct receipts when viewing a room matrix-org/matrix-react-sdk#10864
• Let TimelinePanel only send a receipt if there is an event matrix-org/matrix-react-sdk#10912

Fix a problem where we were sending unthreaded receipts from the main timeline.

However, by fixing them, we have made a lot more unread threads appear. (Previously they were erroneously marked as read when you read something in the main timeline.)

This makes our existing problems with stuck notifications much worse. Many users are reporting many rooms with stuck unreads and stuck notifications. Specifically, we have the wrong order of events in threads, so we don't correctly identify that a receipt applies to events, because we think they are after the receipt, when they are not. This will eventually by fixed by MSC3981, which allows us to fetch the events from the homeserver in the correct order.

Workaround:

• Mark the room as read (on the right-click menu in the room list), and if that doesn't work,
• Send a message a message in the room and then mark the room as read.

[jeffrson]

AFAICT, this is not fixed with 1.11.32-rc.2 (docker).

I still have desktop notifications coming up when reloading the instance. And some rooms stay "unread", even if "mark as read" is called.

The latter happens, when the last message in the room comes from a thread (which itself is read!). Yes, usually it vanishes as soon as there is a new message in the room (unthreaded).

Logs submitted.

[andybalaam]

@jeffrson thank you for the report. I would like to leave this issue closed because it tracks the fact that lots of these unreads have been fixed, but we are aware that there are still more problems to be tracked down.

If you are able to reproduce problems consistently, can I ask you to log a separate issue? The absolute best bug report on this kind of issue would include:

• steps to make it happen
• screenshots of the rooms involved, with "show hidden events" turned on in devtools
• a dump from the Notification Debug section in devtools
• even better, a note about the event ID of each message in the screenshot

(you can get access to devtools by typing /devtools into the message box.

I know this is annoying to collect, and we should definitely automate it to make it easier, but if you can find time that will really help us find the problems!

It's also worth checking #24392 to see whether your issue has already been reported.