IssueTracker

Component used: HorizontalGridView
Version used:1.0.0
Devices/Android versions reproduced on:Android9

If this is a bug in the library, we would appreciate if you could attach:
- Sample project to trigger the issue.
- A screenrecord or screenshots showing the issue (if UI related).

STR:
- inflate HorizontalGridView with items
- make one of the HorizontalGridView's focused
- update HorizontalGridView using DiffUtils so all the list should be recreated
AR: Crash

java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.ViewParent android.view.View.getParent()' on a null object reference
        at androidx.recyclerview.widget.RecyclerView.findContainingItemView(RecyclerView.java:4792)
        at androidx.recyclerview.widget.RecyclerView$LayoutManager.findContainingItemView(RecyclerView.java:8706)
        at androidx.leanback.widget.GridLayoutManager.findImmediateChildIndex(GridLayoutManager.java:3153)
        at androidx.leanback.widget.GridLayoutManager.onAddFocusables(GridLayoutManager.java:3302)
        at androidx.recyclerview.widget.RecyclerView.addFocusables(RecyclerView.java:2943)
        at android.view.ViewGroup.addFocusables(ViewGroup.java:1290)
        at android.view.ViewGroup.addFocusables(ViewGroup.java:1290)
        at android.view.ViewGroup.addFocusables(ViewGroup.java:1290)
        at android.view.View.addFocusables(View.java:11178)
        at android.view.FocusFinder.findNextFocus(FocusFinder.java:108)
        at android.view.FocusFinder.findNextFocus(FocusFinder.java:80)
        at android.widget.ScrollView.onRequestFocusInDescendants(ScrollView.java:1505)
        at android.view.ViewGroup.requestFocus(ViewGroup.java:3236)
        at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:3282)
        at android.view.ViewGroup.requestFocus(ViewGroup.java:3231)
        at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:3282)
        at android.view.ViewGroup.requestFocus(ViewGroup.java:3231)
        at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:3282)
        at android.view.ViewGroup.requestFocus(ViewGroup.java:3231)
        at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:3282)
        at android.view.ViewGroup.requestFocus(ViewGroup.java:3231)
        at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:3282)
        at android.view.ViewGroup.requestFocus(ViewGroup.java:3231)
        at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:3282)
        at android.view.ViewGroup.requestFocus(ViewGroup.java:3236)
        at android.view.View.requestFocus(View.java:11487)
        at android.view.View.requestFocus(View.java:11429)
        at android.view.View.rootViewRequestFocus(View.java:7118)
        at android.view.View.clearFocusInternal(View.java:7104)
        at android.view.View.clearFocus(View.java:7080)
        at android.view.ViewGroup.clearFocus(ViewGroup.java:1139)
        at android.view.ViewGroup.removeDetachedView(ViewGroup.java:5624)
        at androidx.recyclerview.widget.RecyclerView.removeDetachedView(RecyclerView.java:4350)
        at androidx.recyclerview.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:6165)
        at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:6118)
        at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:6114)
        at androidx.leanback.widget.GridLayoutManager.getViewForPosition(GridLayoutManager.java:1109)
        at androidx.leanback.widget.GridLayoutManager$2.createItem(GridLayoutManager.java:1632)
        at androidx.leanback.widget.SingleRow.appendVisibleItems(SingleRow.java:113)
        at androidx.leanback.widget.Grid.appendOneColumnVisibleItems(Grid.java:389)
        at androidx.leanback.widget.GridLayoutManager.appendOneColumnVisibleItems(GridLayoutManager.java:1856)
        at androidx.leanback.widget.GridLayoutManager.onLayoutChildren(GridLayoutManager.java:2286)
        at androidx.recyclerview.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:4134)
        at androidx.recyclerview.widget.RecyclerView.dispatchLayout(RecyclerView.java:3851)
        at androidx.recyclerview.widget.RecyclerView.consumePendingUpdateOperations(RecyclerView.java:1897)
        at androidx.recyclerview.widget.RecyclerView$1.run(RecyclerView.java:414)
        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:949)
        at android.view.Choreographer.doCallbacks(Choreographer.java:761)
        at android.view.Choreographer.doFrame(Choreographer.java:693)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:935)