Affects OpenJDK 17.0.6, 20+36-2344 (GA), 21-ea+10-784.

With the following classes:

public class TopLevel {
    public Class<?> myInstanceMethod() {
        class InstanceMethodNamedClass {
            public InstanceMethodNamedClass(@MyParameterAnnotation String foo) {
            }
        }
        return InstanceMethodNamedClass.class;
    }
}

@Target({ ElementType.PARAMETER })
@Retention(RetentionPolicy.RUNTIME)
public @interface MyParameterAnnotation {
}

... calling `getParameterAnnotations()`on the constructor of `InstanceMethodNamedClass` will return an array that excludes the implicit enclosing parameter representing the instance of `TopLevel`:

var clazz = new TopLevel().myInstanceMethod();
var constructor = clazz.getDeclaredConstructors()[0];
assert constructor.getParameters().length == 2; // succeeds
assert constructor.getParameterAnnotations().length == 2; // fails; length is actually 1

This behavior seems wrong since the javadoc of getParameterAnnotations() states:

> Synthetic and mandated parameters (see explanation below), such as the outer "this" parameter to an
> inner class constructor will be represented in the returned array


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Executable reproducer: see https://github.com/yrodiere/jdk-playground/tree/parameter-annotations, check out branch "parameter-annotations" and run `./mvnw clean install`

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Relates to JDK-8180892.

This bug is similar to JDK-8074977, but different since it is still present after JDK-8074977 was fixed.