Retry policy doesn't work properly if it contains `.handleResult(null)`

[stsdema28]

The following code demonstrates the issue that happens when a retry policy contains .handleResult(null):

public class Issue {

    static String doSomething() {
        throw new NullPointerException();
    }

    public static void main(String[] args) {
        RetryPolicy<Object> retryPolicy = new RetryPolicy<>()
                .handle(IllegalArgumentException.class)
                .handleResult(null)
                .withMaxRetries(2)
                .onRetry(e -> System.out.println("retry attempt: " + e.getAttemptCount()));

        try {
            Failsafe.with(retryPolicy).get(Issue::doSomething);
        } catch (NullPointerException e) {
            System.out.println("It should not retry on NullPointerException");
        }
    }
}

The above prints:

retry attempt: 1
retry attempt: 2
It should not retry on NullPointerException

which means that it retried due to NullPointerException.

If we remove .handleResult(null), it prints:

It should not retry on NullPointerException

which is the correct behaviour as it should retry only on IllegalArgumentException.class.

Just to note, the issue is only with null. If we specify any other value e.g .handleResult("hello world"), there is no problem.

[jhalterman]

Fixed in 73019c0aabf1ca6d2229748e3dc797a74d8f4cf0.

[jhalterman]

This is released in 2.3.4.