According to spec (http://download.java.net/jdk9/docs/api/java/lang/invoke/MethodHandles.html#loop-java.lang.invoke.MethodHandle:A...-),
Step3.c:
If a pred function is omitted, the corresponding fini function must also be omitted.

Considering factorial example from specification, let's add null 'pred' and MH_fin 'fini' function to counterClause.

Expected result: IllegalArgumentException.
Actual result: no exceptions, code works as before


Was found on jdk9 b106, b107. Tests are under development, tck_red label will be added after development completion.
Example attached