Issue520.java

// @skip-test

// Test case for issue #520: https://github.com/typetools/checker-framework/issues/520

// compile with: $CHECKERFRAMEWORK/checker/bin-devel/javac -g Issue520.java -processor nullness -AprintAllQualifiers

import java.util.ArrayList;
import java.util.List;
import org.checkerframework.checker.nullness.qual.*;

public class Issue520 {}

abstract class Parent<T> {
    protected final List<? super @KeyForBottom T> list;

    public Parent(List<? super @KeyForBottom T> list) {
        this.list = list;
    }
}

abstract class Child extends Parent<CharSequence> {
    public Child(List<? super CharSequence> list) {
        super(list);
    }

    public void add(CharSequence seq) {
        list.add(seq);
    }
}

class WildCardAdd {
    List<@UnknownKeyFor ? super @KeyForBottom CharSequence> wildCardList =
            new ArrayList<@KeyForBottom CharSequence>();

    void foo(
            List<@KeyFor("m") CharSequence> keyForMCharSeq,
            @UnknownKeyFor CharSequence unknownCharSeq) {
        wildCardList = keyForMCharSeq;
        wildCardList.add(unknownCharSeq);
        @KeyFor("y") Object o = wildCardList.get(0);
    }
}