FULL PRODUCT VERSION :
java version "1.8.0_25"
Java(TM) SE Runtime Environment (build 1.8.0_25-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.25-b02, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
CentOS 7 and RHEL 7

A DESCRIPTION OF THE PROBLEM :
When I pressed Shift and move mouse wheel the event is received as a MouseEvent instead MouseWheelEvent.
 
isPopupTrigger was also returning true but this was fixed in JDK-8057156.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
This can be tested in http://docs.oracle.com/javase/tutorial/uiswing/events/mousewheellistener.html the mousewheelevent is never printed when Shift is down.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
MouseWheelEvent printed in the scrollpanel.
ACTUAL -
MouseWheelEvent is never detected when Shift is down.

REPRODUCIBILITY :
This bug can be reproduced always.