A DESCRIPTION OF THE PROBLEM :
Calling lookup.findVirtual(int[].class, "clone", MethodType.methodType(Object.class)) with a lookup that is not in the package java.lang will give a MethodHandle with the type (<lookup.lookupClass()>)Ljava/lang/Object; instead of ([I)Ljava/lang/Object;

Using the publicLookup works correctly because its lookupClass is java.lang.Object. This is why the tests added in JDK-8001105 pass.

https://github.com/openjdk/jdk/blob/c2e3d7284814cd6b49f44b4de18e0f92310422b0/src/java.base/share/classes/java/lang/invoke/MethodHandles.java#L3940

Additionally, you can use a lookup from Lookup.in(Class) and it will give you a MethodHandle to clone an object that doesn't have a public clone method, or implement Clonable, however this is not particularly useful because JVM_Clone will throw CloneNotSupported if it doesn't implement Clonable

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run the following class

import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodType;

class Scratch
{
public static void main(String[] args) throws Throwable
{
MethodHandles.Lookup lookup = MethodHandles.lookup();
MethodHandle mh = lookup.findVirtual(int[].class, "clone", MethodType.methodType(Object.class));
System.out.println(mh.type());
mh.invoke(new int[]{});
}
}


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
it should print `(int[])Object` and complete normally
ACTUAL -
it prints `(Scratch)Object` and throws a ClassCastException

---------- BEGIN SOURCE ----------
import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodType;

class Scratch
{
public static void main(String[] args) throws Throwable
{
MethodHandles.Lookup lookup = MethodHandles.lookup();
MethodHandle mh = lookup.findVirtual(int[].class, "clone", MethodType.methodType(Object.class));
mh.invoke(new int[]{});
}
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
Use a publicLookup, or a lookup from a class in java.lang

FREQUENCY : always