Reinvite, merging local and remote SDPs

[Mike Remski]

JsSIP initiating an INVITE, gets a remote ANSWER, then triggering a
REINVITE off of the RTCSession.connection.

Will the localDescription and remoteDescription get merged/trimmed
(basically will localDescription get trimmed to have only the negotiated
ICE candidates and change of setup?)

From testing and logs it does not appear that it's doing so, other SIP
stacks seem to do this, but I'm not seeing it happen in our application
with JsSIP. It's a nodejs application, not running under a browser,
using the node-webrtc npm to provide the web rtc bits.

thanks