[RFC PATCH 0/3] fast-import: add option command

[Sverre Rabbelier <srabbelier@gmail.com>]

Because I am too impatient to wait for a reply to my earlier mail,
here is an RFC series that demonstrates how I envision the option
command to work.

>From the second patch:

    This allows the frontend to specify any of the supported options as
    long as no non-option command has been given. This way the
    user does not have to include any frontend-specific options, but
    instead she can rely on the frontend to tell fast-import what it
    needs.

This change of course means that old fast-import clients will break
upon receiving an 'option' command (or with an argument they don't
support), but such clients will break with a clear output stating
the reason for the breakage. Newer frontends therefore should only
output options if the user tells them to (by means of a flag/config
option), or at least allow disabling option output.

The main use case for this is hg-git, which I want to modify so that
it uses 'hg fast-export | git fast-import' for the intial import.
However, to do that I need the fast-import part to write a marks
file, that is, --write-marks=git.marks. To simplify this process for
the user, it would be nice if 'hg fast-export' can instead emit an
'option write-marks git.marks' line (hence the test case).

 Sverre Rabbelier (3):
      fast-import: put option parsing code in seperate functions
      fast-import: add option command
      fast-import: test the new option command

 fast-import.c          |  137 ++++++++++++++++++++++++++++++++++++-----------
 t/t9300-fast-import.sh |   33 ++++++++++++
 2 files changed, 138 insertions(+), 32 deletions(-)