s_event_wait always returns 0

[pn2new]

I initialize an event, and then wait on it in a task, using s_event_wait_sec(await, &ev, 1);

This works (execution proceeds when a timeout occurs or the event is set). However, I thought that a timeout would be indicated in the return value. However, it is zero in both cases (timeout or event received). I also do not see where in the code this would be handled.