Re: Issue 732: replaceTrack with the previous one as ended

https://github.com/w3c/webrtc-pc/issues/732

mparis asked:

"what should happen if we try to replaceTrack of an ended track?"

In Section 4.8.1, it is stated:

"Internal changes within the implementation can also result in the connection being marked as needing negotiation. For example, if a MediaStreamTrack enters the ended state because its source device became unavailable."

In Section 4.8.2, it says:


"The negotiation-needed flag is cleared when setLocalDescription is called (either for an offer or answer), and the supplied description matches the state of the tracks/datachannels that currenly exist on theRTCPeerConnection . Specifically, this means that all live tracks have an associated section in the local description with their MSID, all ended tracks have been removed from the local description, and, if any data channels have been created, a data section exists in the local description.
"

[BA] Is it really necessary to mark a connection as needing negotiation because the MediaStreamTrack enters the ended state?  If the above text were to be removed, then replaceTrack() could be called to replace the ended MediaStreamTrack, without requiring negotiation.