Adding your own streams within OnAddStream fails

What steps will reproduce the problem?
1. In peerconnection_client::conductor.cc OnAddStream, rather than sending an 
event to a separate thread, take the code from the NEW_STREAM_ADDED handler in 
UIThreadCallback and put it in OnAddStream.
2. Run two clients on the same machine attached to the same server.
3. The connection will fail.

What is the expected output? What do you see instead?
The logging reports the following two errors:
Error(webrtcsession.cc:241): SetLocalDescription called with action in wrong 
state, action: 0 state: 2
Error(webrtcsession.cc:141): StartIce called before SetLocalDescription

Digging into it, it appears that roapsignalling.cc in the 
ProcessSignalingMessage method has odd behavior. It will call out to 
ProcessRemoteDescription which, in turn, will invoke the OnAddStream handler. 
If you then call AddStream and CommitStreamChanges while inside this handler 
rather than pushing the response out on a seperate thread (as peerconnection 
does), the internal state of roapsignalling is invalid. 

In the correct case, the state_ variable of RoapSignalling is kNew. In the 
incorrect case, the state is kInitializing. This will eventually cause the 
offer to be refused. 

As there are no other relevant callbacks until the OK ROAP message arrives, it 
is unclear how to properly handle the addition of "my" streams when brokering a 
connection with "their" streams. I suspect that thread message methodology of 
peerconnection sample works only by luck and that there is actually a race 
condition here. At the very least the calling logic should handle the usage 
pattern I am trying.

What version of the product are you using? On what operating system?
Using Windows 7

Please provide any additional information below.

Original issue reported on code.google.com by shaunk...@gmail.com on 25 Jun 2012 at 6:04

1yfgT53 / libjingle

Adding your own streams within OnAddStream fails #364