Navigation state desyncs from Fragments when using multiple back stacks [269044426]

Fixed

Bug

Status Update

No update yet.

Description

ia...@gmail.com

created issue #1

Feb 13, 2023 06:31AM

Component used: Navigation

Version used: 2.6.0-alpha05

After upgrading to Navigation 2.6.0-alpha05, swapping to another tab via a bottom bar set up via NavigationUI works the first time, but pressing the back button doesn't work as intended: while the fragment changes, the selected bottom bar item doesn't change.

Sample project: https://github.com/muzei/muzei

Steps to reproduce:

Run Muzei, tap 'Activate' and then 'Set wallpaper' to set Muzei as your wallpaper.
Tap the Muzei icon to complete the tutorial.
Tap the 'Sources' tab on the bottom. Note the tab changes.
Press the system back button.

Expected behavior: you go back to the 'Muzei' fragment and the selected tab updates.

Actual behavior: you go back to the 'Muzei' fragment, but the selected tab does not update.

Comments

il...@google.com <il...@google.com> Feb 13, 2023 03:56PM

Assigned to jb...@google.com.

jb...@google.com <jb...@google.com> Feb 13, 2023 04:28PM

Reassigned to cl...@google.com.

ap...@google.com <ap...@google.com> #2Feb 15, 2023 10:16PM

Yigit, do you have time to fix it?

reemission of the same liveData is racy

cl...@google.com <cl...@google.com> #3Feb 15, 2023 11:24PM

Marked as fixed.

yea i'll take it.

na...@google.com <na...@google.com> #4Feb 22, 2023 07:10PM

Thanks for the detailed analysis. This may not be an issue anymore since we've started using Main.immediate there but I' not sure; I'll try to create a test case.

Issue 269044426