[PATCH v3 0/3] Signed-commit

This is another re-roll of the signed-commit topic.

 - The first patch refactors where the current code invokes gpg for
   signing and verification of tags;

 - The second patch introduces signed commit objects;

 - The third patch teaches "git log/show" to show the signature.

The internal API to drive "gpg" has been updated to better suit the verification side, but I suspect that it needs another round of revamp to slurp in the diagnostic message "gpg" produces to give us better control of the formatting of the output. e.g.

    $ git show --format="%h %s%n%gpgsign" -s HEAD

might want to say:

    a030b7cf log: --show-signature
    RSA key ID 96AFE6CB, Good signature from "Junio C Hamano <gitster@pobox.com>"

or something like that, but the series is not there yet.

Junio C Hamano (3):
  Split GPG interface into its own helper library
  commit: teach --gpg-sign option
  log: --show-signature

 Makefile              |    2 +
 builtin/commit-tree.c |   24 ++++++++-
 builtin/commit.c      |   12 ++++-
 builtin/merge.c       |   16 +++++-
 builtin/tag.c         |   76 ++-------------------------
 builtin/verify-tag.c  |   36 ++-----------
 commit.c              |   74 ++++++++++++++++++++++++++-
 commit.h              |    5 ++-
 gpg-interface.c       |  137 +++++++++++++++++++++++++++++++++++++++++++++++++
 gpg-interface.h       |   10 ++++
 log-tree.c            |   17 ++++++
 notes-cache.c         |    2 +-
 notes-merge.c         |    2 +-
 revision.c            |    2 +
 revision.h            |    1 +
 tag.c                 |    5 ++
 16 files changed, 310 insertions(+), 111 deletions(-)
 create mode 100644 gpg-interface.c
 create mode 100644 gpg-interface.h