Re: [WIP 08/15] connect: discover protocol version outside of get_remote_heads

Brandon Williams [off-list ref] writes:

While we could wrap the preamble into a function it sort of defeats the
purpose since you want to be able to call different functions based on
the protocol version you're speaking.  That way you can have hard
separations between the code paths which operate on v0/v1 and v2.

As I envision that the need for different processing across protocol
versions in real code would become far greater than it would fit in
cases within a single switch() statement, I imagined that the reader
structure would have a field that says which version of the protocol
it is, so that the caller of the preamble thing can inspect it later
to switch on it.