[REG 4.8.5->5.4.2] After releasing stylus button widget stops receiving TabletMove events

This issue can be reproduced on the qtbase\examples\widgets\widgets\tablet example code. Simple steps:

1. Start drawing with stylus
2. While drawing click button on stylus
3. After releasing the button app stops drawing
EXPECTED: App keeps drawing

The reason of this behavior is that QTabletEvent is not reported to the widget anymore. Qt starts reporting it back when button is down and stops after releasing. So it looks to me that TabletMove event behaves just like MouseMove event without mouse tracking.

This works as expected with qt 4.8.5 on the same example.

I tried this on both Windows and Mac with Wacom Intuos pro tablet.