State changes and a "transitioning" state

[Carlos Rafael Giani]

Hello,

state changes happen asynchronously. It makes sense to let an 
application move to a transitioning state until the GStreamer state 
change is finished. During this state, further state change attempts 
could be blocked, seeking could be disabled etc.

However, I wonder about two things:

1) What happens if a state change fails? What message is sent to the bus?
2) Do I always get a bus message after a state change? Even if 
set_state() was called with the same state as the current one? If not, 
in what situations aren't state change completions signaled? I want to 
avoid having the application stuck in a transitioning state forever 
because it didn't notice the state change.

cheers