Sent messages not shown after narrowing from a notification

[borisyankov]

@rishig and @timabbott reported an issue where after narrowing to a PM conversation from a notification, sent messages were not displayed.

I was not able to reproduce the issue trying it in several different configurations and states, but it remains high-priority.

[zulipbot]

Hello @zulip/server-notifications members, this issue was labeled with the "area: notifications" label, so you may want to check it out!

[gnprice]

FWIW I also saw this several times a couple of weeks ago. I saw it on 13.2.86, and not sure if I did on 13.3.87.

Rishi, Tim, and I all use Android phones, so it's possible this only repros on Android.

[borisyankov]

There was a significant bug fix related to this 4-5 weeks ago, but this is on a newer version.
I have a good guess for a specific behavior that I do not consider a bug as we intended it to work that way, but might result in this.
Surprisingly, testing on several different configurations and states I was not able to reproduce.

The reason a user might not be seeing message updates is that he is not 'caught up' to the newest messages. This can happen if:

• he is missing the latest messages
• we do not know if he is missing the latest messages (app was in the background, polling was interrupted)

Other behavior that might feel buggy (but is intended and we might want to change):

• on narrow from notification we show the latest unread message
• several users reported as bug and expected to be shown the message they tapped on (which in case is not the latest unread is not shown)

[gnprice]

​When I observed this, I had the latest messages in the thread. If a user didn't but we made it look like they did (they're at the end, and there's no indication that anything is loading, even if they wait a moment or attempt to overscroll), that'd be a bug in itself, and we've had bugs like that. But that's not what happened when I observed this bug. These were PM threads with just a couple of new messages, so the difference between "first unread" and "latest message" wasn't significant either.

[gnprice]

Given our diagnosis of #2800 , it strikes me that this might be a symptom of the same underlying bug: we lose our event queue and don't realize it, so although our initial fetch for the narrow works fine, we never see new messages come in thereafter.

[gnprice]

I'd be very interested to hear from anyone seeing this symptom on 15.0.92 (which went out to all Android users yesterday, and into Apple's review process to get it to iOS users), which has the fix for #2800. That bug definitely would cause this behavior, so I'm hoping it was the cause.

[gnprice]

Haven't seen or heard of this after that release; so it looks like this was indeed caused by #2800 and is now fixed.