Keyboard focus is lost when popping multiple screens with Navigator.popuntil

[gmoraja]

@goderbauer
@gspencergoog
@lorenzOliveto

Steps to reproduce:

• Attach a keyboard to an Android device
• push multiple Widget in the navigator stack
• going back to the root with Navigator.popUntil

The keyboard focus is lost and it doesn’t respond anymore. You can find an example in this repository, https://github.com/lorenzOliveto/flutter_keyboard_navigation_issues (pop_until_example.dart).

[gmoraja]

@gspencergoog we tested this in the most recent master but we haven't noticed any difference in the behavior, should we open a new issue or wait for an update?

[chunhtai]

Taking a look

[chunhtai]

Ok, I found the issue, My fix does not fix all the possible use cases.
Will put up another pr to make the focus traversal more robust