Stream.take(0) doesn't forward errors any more.

[lrhn]

We are fixing a bug in Stream.take with a zero count that made it not cancel the subscription immediately. It should, and now it does, which also means that two tests are now failing:

• LibTest/async/Stream/take_A01_t02
• LibTest/isolate/ReceivePort/take_A01_t02

Both seem to assume that .take(0) will still propagate an error event, which it now won't.

The description of Stream.take was a little confusing, and will also be cleaned up. It did say that the subscription was cancelled after [count] events had been received, which is now true even for count == 0.

[alsemenov]

I think current description is still confusing:

Forwards the first n data events of this stream, and all error events, to the returned stream, and ends with a done event.

I conclude that error events are received without any restrictions.
If I understand correctly, the .take(0) works as follows:

StreamSubscription ss = stream.listen(...);
ss.cancel();

Is there a possibility, that between these lines the stream generates some error (in another thread for example) and this error is received?

[lrhn]

The current documentation on the bleeding edge branch now says:

Provides at most the first [count] data events of this stream.

Forwards all events of this stream to the returned stream
until [count] data events have been forwarded or this stream ends,
then ends the returned stream with a done event.

If this stream produces fewer than [count] data events before it's done,
so will the returned stream.

Starts listening to this stream when the returned stream is listened to
and stops listening when the first [count] data events have been received.

This means that if this is a single-subscription (non-broadcast) streams
it cannot be reused after the returned stream has been listened to.

If this is a broadcast stream, the returned stream is a broadcast stream.
In that case, the events are only counted from the time
the returned stream is listened to.

I believe it will be published with the 1.21 release.