A DESCRIPTION OF THE REQUEST :
javafx.application.Platform.exit() exits FX application and JVM even if permission exitVM is not granted by SecurityManager.



JUSTIFICATION :
It is possible to prevent exiting JVM with SecurityManager with permission exitVM.
However, this permission does not prevent exiting JVM with  javafx.application.Platform.exit(). 

This is inconsistent and unexpected behavior. 

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Two options:

1) If exitVM is not granted to a class, FX application should throw an exception when an instance of this class calls javafx.application.Platform.exit(). FX application should not terminate.

2) Implement a new target for javafx.util.FXPermission to prevent exiting FX application by calling javafx.application.Platform.exit().
ACTUAL -
When an instance of a class from an external library calls javafx.application.Platform.exit(), FX application and JVM exit even if exitVM is not granted to this instance by SecurityManager.