Reported on https://mail.openjdk.java.net/pipermail/jdk-dev/2021-October/006099.html

This is to follow up the behavorial change on LambdaMetaFactory::metafactory when the implementation is REF_invokeSpecial method handle on a public/protected method in the target class. This won't happen for classes compiled from javac since REF_invokeSpecial method handle is generated when the method is a private method whereas REF_invokeVirtual method handle would be generated on a public/protected.

To reproduce:
1. compile it with java 8
2. modify the access of testPrivate from private to public in .class file (do not modify any invokespecial and ref_invokespecial).
3. Java 14 without JEP 371, the method reference `this::testPrivate` with REF_invokeSpecial kind will be resolved to ExampleClass::testPrivate on a receiver of type ExampleClass$SubClass. With JEP 371 change, the method reference `test::testPrivate` with REF_invokeSpecial kind will be resolved to ExampleClass$Subclass::testPrivate instead.


import java.util.function.Supplier;

public class ExampleClass {
    public static void main(String[] args) {
        System.out.println(new SubClass().test());
        System.out.println(new SubClass().testWithLMF());
    }

    public String test() {
        return this.testPrivate();
    }

    public String testWithLMF() {
        Supplier<String> supplier = this::testPrivate;
        return supplier.get();
    }

    private String testPrivate() {
        return "123";
    }

    public static class SubClass extends ExampleClass {
        public String testPrivate() {
            return "456";
        }
    }
}

Java 14:

$ java ExampleClass
123
123

Java 15:

$ java ExampleClass
123
456