IssueTracker

It could easy to reproduce when turning on "Don't keep activities".

Project: platform/frameworks/support
Branch: androidx-master-dev

commit ba0c19707915ff87d9cac2089fcd166bb5cca17d
Author: Ian Lake <ilake@google.com>
Date:   Wed Nov 14 16:20:28 2018

    Set the correct FragmentManager on active Fragments
   
    All active Fragments should have the correct
    FragmentManager set instead of always using the
    Activity's FragmentManager.
   
    While added Fragments have their FragmentManager
    set correctly in moveToState(), active Fragments
    weren't being set correctly, causing issues when
    attempting to save the state of the FragmentManager.
   
    Test: new FragmentLifecycleTest
    BUG: 119256498
    Change-Id: I830f729d93f00859509a0844fae19752342e6ccc

M       fragment/src/androidTest/java/androidx/fragment/app/FragmentLifecycleTest.java
M       fragment/src/main/java/androidx/fragment/app/FragmentManagerImpl.java
M       fragment/src/main/java/androidx/fragment/app/FragmentState.java

https://android-review.googlesource.com/826954
https://goto.google.com/android-sha1/ba0c19707915ff87d9cac2089fcd166bb5cca17d