According to documentation j.l.i.MethodHandles.whileLoop(MethodHandle, MethodHandle, MethodHandle), 'init' might be void:

Passing void init function will make the loop's result type void.

Attached code provides example which throw IllegalArgumentException; 'java.lang.IllegalArgumentException: parameter type cannot be void'


Was found on jdk9b107, tests are in development, tck_red label will be added after tests development completion.