Jonathan Tan [off-list ref] writes:
We could make the caller of demultiplex_sideband() store the outbuf, but
at this point, it might be better to refactor packet_reader into its own
file and have it depend on both pkt-line.h and sideband.h.
I do not know or too deeply care about the pkt-line / sideband
distinction, as they are logically one thing. With a packet-reader
abstraction in place, doesn't this "here is the remainder of the
packet from the previous round" belong to each reader instance?