/*
 * @test
 * @summary Test for Issue 347: concurrent semantics has desired behavior
 *
 * @compile -XDrawDiagnostics -processor org.checkerframework.checker.nullness.NullnessChecker -Alint Issue347.java
 * @compile/fail/ref=Issue347-con.out -XDrawDiagnostics -processor org.checkerframework.checker.nullness.NullnessChecker -Alint Issue347.java -AconcurrentSemantics
 */

import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
import org.checkerframework.checker.nullness.qual.Nullable;

class Issue347 {

    @MonotonicNonNull String mono;

    @Nullable String nble;

    void testMono() {
        if (mono == null) {
            return;
        }
        // The object referenced by mono might change, but
        // it can't become null again, even in concurrent
        // semantics.
        mono.toString();
    }

    void testNble() {
        if (nble == null) {
            return;
        }
        // error expected in concurrent semantics only
        nble.toString();
    }
}