2.x Calling hasNext() on a disposed blocking iterator hangs forever

[BrynCooke]

Calling hasNext() on a a blocking iterator never returns if the iterator has been disposed.

Tested on 2.2.11

To reproduce:

Iterator<Integer> iterator = Flowable.fromArray(1, 2, 3).delay(1, TimeUnit.SECONDS).blockingIterable().iterator();

System.out.println("start");
((Disposable)iterator).dispose();
iterator.hasNext(); //Hangs forever

[akarnokd]

Indeed, if you "hack" into that Iterator it won't work properly as it implementing Disposable is not part of the public intended API. I'll see what I can do about it in 2.x. For 3.x, it probably needs some redesign to work with try-with-resources for example.

[akarnokd]

Closing via #6626 & #6627.