Added simple example "line-edit with clear button" written by Laurent,
to demonstrate the issue.
This leads to a "Type error" warning in MobileTextActionsToolBar.qml
or more precisely with my qtdeclarative fix
https://codereview.qt-project.org/c/qt/qtdeclarative/+/263542
it says:
MobileTextActionsToolBar.qml:47: TypeError: Cannot read property 'height' of null
which means controlRoot.Window.contentItem is null.
I'm not 100% confident with this fix, because it feels like stuff
won't be updated when contentItem is non-null later... But I can't
see a bug, I guess it would only happen on mobile?