Flowable.groupBy hangs with group consumed via observeOn and take(timed) #6982
Description
Continuing evaluating the problems from #6974
The following test hangs after a while:
@Test public void issue6974Part2Case1ObserveOnNoCap() { final int groups = 20; int flatMapMaxConcurrency = 1_000_000; Flowable .range(1, 500_000) .map(i -> i % groups) .doOnRequest(v -> { System.out.println("Source: " + v); }) .groupBy(i -> i) .flatMap(gf -> gf .observeOn(Schedulers.computation()) .take(10, TimeUnit.MILLISECONDS) , flatMapMaxConcurrency) .test() .awaitDone(5, TimeUnit.SECONDS) .assertNoErrors() .assertComplete(); }Adding hide makes it pass which indicates the fusion between the group and observeOn seems to stop requesting more items.