This is a regression from 4.7.0.

Steps to reproduce (this is a Mac only issue):
1. Open app, select a window that has a parent (call this window W). In the example app, select any window except Win MAIN.
2. Press Cmd+H or choose Hide from the app menu.
3. Click on the application icon or otherwise make the app active.

The window W remains hidden even though it was visible before hiding the app.

Notes:
This happens for widgets with the Qt::Window window flag set that have a parent.

In the attached file, this only happens for Win 0, Win 1, Win 2, etc., not Win MAIN.