As discovered in bug 960902, we may get to trouble when reading the rest of the data the initial writer failed to receive from the server. The subsequent range request in the same http channel is a ticking bomb IMO. Better would be to do an internal redirect to load the rest of the data. It however probably means some special code on nsHttpChannel to allow external setup of a range request.

After OnStartRequest notification to the channel's listener we cannot redirect to a new channel and pass the listener to the new channel. Hence this whole idea is non-sense.