JSpecify: false positive when ? super T is on the both sides of call and T is nullable

[unv-unv]

@NullMarked
public class Test {
    static class Foo<T extends @Nullable Object> {
        public static <T extends @Nullable Object> Foo<T> of(Foo<? super T> foo) {
            return new Foo<>();
        }

        public Foo<T> or(Foo<? super T> other) {
            return this;
        }
    }

    // BUG: [NullAway] incompatible types: Foo<Void> cannot be converted to Foo<@Nullable Void>
    static final Foo<@Nullable Void> FOO = Foo.of(new Foo<@Nullable Void>()).or(new Foo<@Nullable Void>());
}

Note that if I remove call for .or() everything compiles OK.

static final Foo<@Nullable Void> FOO = Foo.of(new Foo<@Nullable Void>());

The following one is OK too:

static final Foo<@Nullable Void> FOO_BASE = Foo.of(new Foo<@Nullable Void>());
static final Foo<@Nullable Void> FOO = FOO_BASE.or(new Foo<@Nullable Void>());

So the problem appears only if on the both sides of .or() call is ? super T.

NullAway 0.13.1, Error Prone 2.48.0

[msridhar]

Thanks for the report, this is most likely due to incomplete support for wildcards; see #1360 and also #1462. I'll leave this one open and we should check that it's fixed after adding more wildcards support