delay on a range emits two at a time rather than everything at once

[dmgd]

e.g.
range(1, 10).delay(1, SECONDS).subscribe(System.out::println) will result in two numbers being output each second for five seconds, rather than all ten after one second

sample unit test below. more tests and one way of fixing it (just using merge instead of concat) @ dmgd@29f0b80

@Test
public void testDelayEmitsEverything() {
    Observable<Integer> source = Observable.range(1, 5);
    Observable<Integer> delayed = source.delay(500L, TimeUnit.MILLISECONDS, scheduler);
    TestObserver<Integer> observer = new TestObserver<Integer>();
    delayed.subscribe(observer);
    scheduler.advanceTimeBy(500L, TimeUnit.MILLISECONDS);
    observer.assertReceivedOnNext(asList(1, 2, 3, 4, 5));
}

[benjchristensen]

Interesting ... so yes, merge almost gets the behavior we want, but it then allows concurrent execution and that means we can get things out of order which we can't allow.

Figuring out what needs to be done...

[headinthebox]

Nice catch.

[benjchristensen]

Just merged a fix that I believe resolves this while making it work with backpressure.