The fix for JDK-8254350 appears to have been incomplete.
When the test for that fix is modified to add timed get, we again see intermittent failure.

Here's a version of SwallowedInterruptedException that has also been tweaked for jsr166 coding style.

java.lang.AssertionError: Test failed with [timed=true, iteration=65]
Caused by: java.lang.AssertionError: Future.get completed with interrupt status not set


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import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ThreadLocalRandom;
import static java.util.concurrent.TimeUnit.DAYS;
import java.util.concurrent.atomic.AtomicReference;

/*
 * @test
 * @bug 8254350
 * @run main SwallowedInterruptedException
 * @key randomness
 */

// TODO: incorporate into CompletableFuture tck tests

public class SwallowedInterruptedException {
    static final int ITERATIONS = 100;

    public static void main(String[] args) throws Throwable {
        ThreadLocalRandom rnd = ThreadLocalRandom.current();
        for (int i = 1; i <= ITERATIONS; i++) {
            boolean timed = rnd.nextBoolean();
            CompletableFuture<Void> future = new CompletableFuture<>();
            CountDownLatch threadRunning = new CountDownLatch(1);
            AtomicReference<Throwable> fail = new AtomicReference<>();

            Thread thread = new Thread(() -> {
                threadRunning.countDown();

                try {
                    Void result = (timed) ? future.get(1, DAYS) : future.get();

                    if (!Thread.currentThread().isInterrupted()) {
                        fail.set(new AssertionError(
                            "Future.get completed with interrupt status not set"));
                    }
                } catch (InterruptedException ex) {
                    if (Thread.currentThread().isInterrupted()) {
                        fail.set(new AssertionError(
                            "InterruptedException with interrupt status set"));
                    }
                } catch (Throwable ex) {
                    fail.set(ex);
                }
            });
            thread.start();
            threadRunning.await();

            // interrupt thread, then set result after an optional (random) delay
            thread.interrupt();
            long sleepMillis = rnd.nextLong(10);
            if (sleepMillis > 0)
                Thread.sleep(sleepMillis);
            future.complete(null);

            thread.join();
            if (fail.get() != null) {
                throw new AssertionError(
                    String.format("Test failed with [timed=%s, iteration=%d]",
                                  timed, i),
                    fail.get());
            }
        }
    }
}