After discussion with Nicolas and Florent, we've found a few issues with
the ``darcs transfer-mode'' protocol.  I'm filing separate bugs for each
issue.

1. The protocol is not versioned.

This will lead to problems later on.  We recommend a new command

    OPTIONS list of options

to which the server replies

    OPTIONS list of options

Right now, the list of options is empty, so the server should be able to
parse an arbitrary line starting with ``OPTIONS'', and reply with just

    OPTIONS

                                        Juliusz

I wonder if there is a way we can do this without introducing an extra
connection (one more reason to type password).

Perhaps options could be a command that darcs transfer-mode learns to parse?  We
will need to see how old darcs-transfer mode deals with this and how old darcs
client respond accordingly

Better to make this backwards-compatible by making it

get options

so that the existing server can handle it just fine (by sending an
error back, indicating that it's version 1 of the protocol).

David

I suppose we would have to name it something that is unlikely to actually appear
in anybody's repository, for example:

get darcs-transfer-mode-options

That's not necessary, since the namespace isn't shared with files that
are in repositories.

Excellent! Marking ProbablyEasy (especially since we need loads of easy jobs if
we're going to carry on sprinting in the years to come)