Unread messages badge can update before messages arrive

[turt2live]

Description

This is easily reproduced on a slow homeserver. The unread badge count can increment several times before a room actually sees those messages. The user experience is seeing the badge, clicking the room, and discovering no new messages (but the badge clearing). A short while later, the badge updates again to be the same count (+ any other mystery messages) - further confusing the user.

In my case there was a delay of 1-2 minutes between the badge update and new messages.

Version information

• Platform: web (in-browser)
• Browser: Chrome 63
• OS: Windows 10
• URL: riot.im/develop

[turt2live]

Rageshake sent for this in hopes that it'll reveal something.

[lampholder]

In my case there was a delay of 1-2 minutes between the badge update and new messages.

Horrendous.

Am I right in thinking that the client is just reflecting in the unread badge the same message events it received down the sync as will ultimately be rendered in the timeline, so that any delay between the two would be firmly in clientland?

[turt2live]

It seems like it should be client side problems, but I'm not sure it is. It's possible the server is sending the badge counts down /sync before the actual messages, leading to this scenario.

I'm more tempted to blame the server because the room is not encrypted (so that lag isn't an issue here) and the UI is responsive between the badge and message - I can still switch rooms back and forth, send messages, see read receipts falling, etc. Because the UI isn't locked up, I wouldn't expect it to be a rendering problem. The frequency of a major delay is also relatively low (5 or so times per day), and is independent of machine, however I've only observed the issue on web (as I don't use the android app very often anymore). I haven't yet analyzed the actual sync responses though.

[turt2live]

Related: #3363