Maybe I have misunderstood how things work, or I'm using too old
version of jack, but here's what happens:

1. Start jack 2 (jack-audio-connection-kit-devel-1.9.9.5-1.fc17.x86_64)
2. Press the "Start transport rolling" button in qjackctl.
3. Qjackctl reports "Rolling" in the display. 
4. Create jack client
5. Call jack_transport_query(client, NULL).
6. jack_transport_query(client, NULL) always returns JackTransportStopped

Shouldn't jack_transport_query(client, NULL) return JackTransportRolling?

(It doesn't matter whether I activate the client or not before calling jack_transport_query(client, NULL)).