Comment 2 for bug 1527187

dialer-app only update existing calls in the live call screen when it is in foreground. (we unregister the telepathy observer when it's in background to avoid other problems).
If you lock the device with dialer-app open, then unlock it, it is still reported as inactive by Qt.application.active.
If we try to make a call in this state, the app won't be able to control it. (including the hangup button not working)
Once we swipe the app to background and then foreground again it works again, and Qt.application.active reports the right state.

Did we land any change to the dialer-app focus logic on unity recently?