IssueTracker

Component used: androidx.leanback:leanback:1.1.0-alpha05

RowsSupportFragment will be used in the following example, but the issue is also present in other fragments.

App uses single activity architecture with Androidx Navigation component. RowsSupportFragment is declared in the fragment layout xml via a FragmentContainerView using the android:name attribute.
When navigating away and the current fragment is placed in the backstack, the RowsSupportFragment instance is retained and re-used, and leaks the VerticalGridView, and by extension the entire fragment view hierarchy, that should have been destroyed.

When the adapter is set on the RowsSupportFragment, the VerticalGridView's adapter is also set via mVerticalGridView.setAdapter(mBridgeAdapter), which registers the view as an observer inside mBridgeAdapter. In BaseRowSupportFragment's onDestroyView, the mVerticalGridView reference is nulled. However, this is insufficient as mBridgeAdapter still holds a reference to the view as an observer. The VerticalGridView's adapter should also be nulled to clear this reference.

A workaround is by overriding RowsSupportFragment and manually nulling the VerticalGridView's adapter in onDestroyView. But this does not work for something like VerticalGridSupportFragment which does not expose the internal VerticalGridView.