SectionList ListHeaderComponent gets rerendered when sections data changes

🐛 Bug Report

This is a duplicate of:
https://github.com/facebook/react-native/issues/16824
https://github.com/facebook/react-native/issues/16823
https://github.com/facebook/react-native/issues/14249

But since those 3 were closed and they are missing a reproducible example of the bug I'm reopening.

Description

If one uses a TextInput as a ListHeaderComponent when searching and when the returned sections are empty the TextInput loses focus.

If when searching the sections still have data - then the TextInput in the ListHeaderComponent doesn't lose focus.

To Reproduce

https://snack.expo.io/H12h3BgHV

Expected Behavior

I would expect for the TextInput not to lose focus

Code Example

https://snack.expo.io/H12h3BgHV

Environment

[skip envinfo]
RN 0.58

I've been trying to debug this with @pawelczerepak and what we noticed is that VirtualizedCellWrapper
https://github.com/facebook/react-native/blob/master/Libraries/Lists/VirtualizedList.js#L1759
gets unmounted and mounted when sections is an empty array. And when this happens everything inside of it gets unmounted and mounted again.
@sahrens - any ideas on what might be going on here?

Snack の例でフォーカスが失われる現象を再現し、その後、Libraries/Lists/VirtualizedList.js の 1759 行目付近にある VirtualizedCellWrapper のコードを調べてください。sections が空になったときに、それがアンマウントされて再度マウントされる理由を追跡し、セクションデータが変化している間も ListHeaderComponent の TextInput にフォーカスが維持されることを確認してください。