[2.5.3 Java] Not possible to set infinite WS request timeout with stream()

Migrated from https://github.com/playframework/playframework/issues/6225

Play Version (2.5.x / etc)

2.5.3

API (Scala / Java / Neither / Both)

Java

Operating System (Ubuntu 15.10 / MacOS 10.10 / Windows 10)

Windows 8.1

JDK (Oracle 1.8.0_72, OpenJDK 1.8.x, Azul Zing)

Oracle JDK 1.8.0_92

Library Dependencies

None

Expected Behavior

1. Setting setRequestTimeout(-1)for a WSClient request and calling stream() should respect the timeout being infinite.
2. In the case of a timeout it should result in a Throwable being emitted to whenComplete()

Actual Behavior

The following code reaches .whenComplete() without an exception after 120 seconds.

    CompletionStage<StreamedResponse> events = ws.url("https://example.com/events")
            .setMethod("GET")
            .setHeader("Accept", "text/event-stream")
            .setRequestTimeout(-1)
            .stream();
    events.thenCompose(res -> {
        Source<ByteString, ?> responseBody = res.getBody();
        return responseBody.via(Framing.delimiter(ByteString.fromString("\n"), Integer.MAX_VALUE, FramingTruncation.ALLOW)).map(ByteString::utf8String).runForeach(data -> logger.info(data), materializer);
    }).whenComplete((done, throwable) -> {
        if (throwable != null) {
            logger.error(throwable.getMessage(), throwable);
        }
        logger.info("Done");
    });

When setting the timeout to Integer.MAX_VALUE the call doesn't timeout after 120 seconds.
When changing to get() instead of stream() the infinite setting seems to be respected. However this doesn't help with Server-Sent Events and Akka Streams. Might be related to #4846.

Is there a workaround to get an infinite event-stream processing with Play 2.5?

Start by reproducing the Java WSClient stream() example with setRequestTimeout(-1), then compare its behavior with get() and the Integer.MAX_VALUE timeout case. Trace the stream() request-timeout handling and verify completion behavior for the Server-Sent Events example; done means an infinite timeout is respected and timeout failures reach whenComplete().