Unable to clear badge icon

[aleffert]

Running the latest iOS version (v26.29.52) on the latest iOS (13.5.1).

Steps:
Get @mentioned in a message.
Observe badge with a 1 on the homescreen
View message in the iOS app
Close app
Still observe badge with a 1 on the homescreen

Expected:
No more icon badge since I have nothing unread

I also tried opening up with the desktop app as well as explicitly killing the app on my phone.

[chrisbobbe]

Thanks for the report, @aleffert! This is a known issue, and we're working on a fix; you can follow along here if you like.

[chrisbobbe]

Since this issue has the labels a-IOS and a-notifications, I'm marking it as blocked by #4115, so we only have to implement a solution once. The PR #4163 is currently open for that issue.

[gnprice]

#4163 is merged! This is now ripe for working on.

In the meantime, back when this issue was new (a few hours after it was filed -- thanks again @aleffert for the report!) we deployed a workaround: the server always sends a badge count of 0. So the current status should be that the app icon is always clear -- that there's never a badge.

Before we deployed that workaround, I reproduced this issue myself:
https://chat.zulip.org/#narrow/stream/243-mobile-team/topic/iOS.20badge.20count/near/926367

So I expect that if we simply reverted the workaround and started sending badge counts, this issue would reappear.

We did fix, as part of #4163, an issue that would have caused the badge count not to update when the app was in the foreground. That could cause symptoms similar to this one; in particular it'd be enough to explain the original report in this thread. But it doesn't explain the repro I described at the link above:

• The app was never in the foreground.
• The badge count did successfully update from 3 down to 1 (when it should have been 0); then correctly up to 2; then back down to 1 when it again should have gone to 0.