Fix NPE on goto to invalid method reference

[mbien]

• check if element is a record before listing components
• removed reflective method calls and updated logic
• added regression test

reproducer:

public class GoToInvalidMethodReferenceNPE {
    public static void main(String args[]) {
        ChangeListener listener = GoToInvalidMethodReferenceNPE::invalid;
        //                                                       ^^^^^^^ ctrl click (after parsing)
    }
}

fixes #8735

[mbien]

is this cast ok?

[lahodaj]

I think it mostly is OK. And it basically weakly suggests that peer.getEnclosingElement() == enclosing, which should be always true. (I probably would just do enclosing.getEnclosingElement(), though.)

I wonder if it is possible to write a test for this - I can try at some point if needed.

Otherwise - great cleanup, thanks for doing this!

[mbien]

(I probably would just do enclosing.getEnclosingElement(), though.)

you mean changing

    for (RecordComponentElement component : ((TypeElement)peer.getEnclosingElement()).getRecordComponents()) {

into

    for (RecordComponentElement component : ((TypeElement)enclosing).getRecordComponents()) {

good idea,

[mbien]

added regression test and updated the logic so that it breaks out of both loops instead of just the inner loop.