RxJava 2.0.4 Observable calls dispose before terminal event.

[StanislavChumarin]

Recently discovered behaviour that brings incorrect order for Observable.doFinally

Here is code to check

    @Test
    public void operationFinallyOrder() throws Exception {
        Single.error(new RuntimeException())
                .doOnDispose(() -> System.out.println("Single.doOnDispose"))
                .doFinally(() -> System.out.println("Single.doFinally"))
                .subscribe(o -> System.out.println("Single.onSuccess"),
                        t -> System.out.println("Single.onError"));
        System.out.println();

        Completable.error(new RuntimeException())
                .doOnDispose(() -> System.out.println("Completable.doOnDispose"))
                .doFinally(() -> System.out.println("Completable.doFinally"))
                .subscribe(() -> System.out.println("Completable.onComplete"),
                        t -> System.out.println("Completable.onError"));
        System.out.println();

        Observable.error(new RuntimeException())
                .doOnDispose(() -> System.out.println("Observable.doOnDispose"))
                .doFinally(() -> System.out.println("Observable.doFinally"))
                .subscribe(o -> System.out.println("Observable.onNext"),
                        t -> System.out.println("Observable.onError"),
                        () -> System.out.println("Observable.onComplete"));
        System.out.println();

        Observable.just(new Object())
                .doOnDispose(() -> System.out.println("Observable.doOnDispose"))
                .doFinally(() -> System.out.println("Observable.doFinally"))
                .subscribe(o -> System.out.println("Observable.onNext"),
                        t -> System.out.println("Observable.onError"),
                        () -> System.out.println("Observable.onComplete"));
    }

Output:

Single.onError
Single.doFinally

Completable.onError
Completable.doFinally

Observable.doOnDispose
Observable.doFinally
Observable.onError

Observable.onNext
Observable.doOnDispose
Observable.doFinally
Observable.onComplete

As you can see, order and amount of messages for Single and Completable are correct, but LambdaObserver calls dispose before terminal event. That triggers doFinally too early.
According to new lifecycle (confirmed here #4811) no messages Observable.doOnDispose should be there.

[akarnokd]

Indeed, Observable behaves differently from Flowable:

Flowable.onError
Flowable.doFinally

Flowable.onNext
Flowable.onComplete
Flowable.doFinally

I'll post a fix shortly.

[akarnokd]

See #4957

[akarnokd]

Closing via #4957