[AppBarLayout] HeaderScrollingViewBehavior issue

here's the crash log i received on crashlytics

Fatal Exception: java.lang.NullPointerException: Attempt to write to field 'boolean android.animation.AnimatorSet$Node.mEnded' on a null object reference at android.animation.AnimatorSet.onChildAnimatorEnded(AnimatorSet.java:799) at android.animation.AnimatorSet.start(AnimatorSet.java:640) at android.animation.StateListAnimator.start(StateListAnimator.java:188) at android.animation.StateListAnimator.setState(StateListAnimator.java:181) at android.view.View.drawableStateChanged(View.java:18049) at android.view.ViewGroup.drawableStateChanged(ViewGroup.java:6479) at android.view.View.refreshDrawableState(View.java:18108) at android.view.View.dispatchAttachedToWindow(View.java:15589) at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2955) at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2962) at android.view.ViewGroup.addViewInner(ViewGroup.java:4510) at android.view.ViewGroup.addView(ViewGroup.java:4312) at android.view.ViewGroup.addView(ViewGroup.java:4252) at android.view.ViewGroup.addView(ViewGroup.java:4225) at androidx.viewpager2.adapter.FragmentStateAdapter.addViewToContainer(FragmentStateAdapter.java:406) at androidx.viewpager2.adapter.FragmentStateAdapter.placeFragmentInViewHolder(FragmentStateAdapter.java:328) at androidx.viewpager2.adapter.FragmentStateAdapter.onViewAttachedToWindow(FragmentStateAdapter.java:273) at androidx.viewpager2.adapter.FragmentStateAdapter.onViewAttachedToWindow(FragmentStateAdapter.java:73) at androidx.recyclerview.widget.RecyclerView.dispatchChildAttached(RecyclerView.java:8377) at androidx.recyclerview.widget.RecyclerView$5.addView(RecyclerView.java:954) at androidx.recyclerview.widget.ChildHelper.addView(ChildHelper.java:131) at androidx.recyclerview.widget.RecyclerView$LayoutManager.addViewInt(RecyclerView.java:9430) at androidx.recyclerview.widget.RecyclerView$LayoutManager.addView(RecyclerView.java:9388) at androidx.recyclerview.widget.RecyclerView$LayoutManager.addView(RecyclerView.java:9375) at androidx.recyclerview.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1676) at androidx.recyclerview.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1622) at androidx.recyclerview.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:687) at androidx.recyclerview.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:4645) at androidx.recyclerview.widget.RecyclerView.dispatchLayout(RecyclerView.java:4348) at androidx.recyclerview.widget.RecyclerView.onLayout(RecyclerView.java:4919) at android.view.View.layout(View.java:17702) at android.view.ViewGroup.layout(ViewGroup.java:5631) at androidx.viewpager2.widget.ViewPager2.onLayout(ViewPager2.java:535) at android.view.View.layout(View.java:17702) at android.view.ViewGroup.layout(ViewGroup.java:5631) at com.google.android.material.appbar.HeaderScrollingViewBehavior.layoutChild(HeaderScrollingViewBehavior.java:149) at com.google.android.material.appbar.ViewOffsetBehavior.onLayoutChild(ViewOffsetBehavior.java:43) at androidx.coordinatorlayout.widget.CoordinatorLayout.onLayout(CoordinatorLayout.java:953) at android.view.View.layout(View.java:17702) at android.view.ViewGroup.layout(ViewGroup.java:5631) at android.widget.FrameLayout.layoutChildren(FrameLayout.java:325) at android.widget.FrameLayout.onLayout(FrameLayout.java:261) at android.view.View.layout(View.java:17702) at android.view.ViewGroup.layout(ViewGroup.java:5631) at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1762) at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1606) at android.widget.LinearLayout.onLayout(LinearLayout.java:1515) at android.view.View.layout(View.java:17702) at android.view.ViewGroup.layout(ViewGroup.java:5631) at android.widget.FrameLayout.layoutChildren(FrameLayout.java:325) at android.widget.FrameLayout.onLayout(FrameLayout.java:261) at android.view.View.layout(View.java:17702) at android.view.ViewGroup.layout(ViewGroup.java:5631) at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1762) at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1606) at android.widget.LinearLayout.onLayout(LinearLayout.java:1515) at android.view.View.layout(View.java:17702) at android.view.ViewGroup.layout(ViewGroup.java:5631) at android.widget.FrameLayout.layoutChildren(FrameLayout.java:325) at android.widget.FrameLayout.onLayout(FrameLayout.java:261) at com.android.internal.policy.DecorView.onLayout(DecorView.java:774) at android.view.View.layout(View.java:17702) at android.view.ViewGroup.layout(ViewGroup.java:5631) at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2519) at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2234) at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1372) at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6774) at android.view.Choreographer$CallbackRecord.run(Choreographer.java:926) at android.view.Choreographer.doCallbacks(Choreographer.java:735) at android.view.Choreographer.doFrame(Choreographer.java:667) at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:912) at android.os.Handler.handleCallback(Handler.java:761) at android.os.Handler.dispatchMessage(Handler.java:98) at android.os.Looper.loop(Looper.java:156) at android.app.ActivityThread.main(ActivityThread.java:6517) at java.lang.reflect.Method.invoke(Method.java) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:942) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:832)

Inizia tracciando lo stack segnalato da HeaderScrollingViewBehavior.layoutChild, passando per ViewPager2 e l’aggancio di FragmentStateAdapter, fino ad arrivare ad AnimatorSet di Android. Riproduci il crash, se possibile, e determina il comportamento rilevante di Material Components; il lavoro è completo quando il crash viene evitato e lo scenario è coperto da test di regressione.