[PATCH v2 00/12] Allow reference values to be checked in a transaction

This is v2 of the patch series, with only minor changes from v1 [1]. Thanks to Stefan Beller and Junio for their feedback about v1. I think I have addressed all of the points that were raised.

Changes since v1:

* Rebased onto new upstream master (because it now includes the
  dependencies, mh/reflog-expire and sb/atomic-push). The rebase was
  conflict-free.

* Tweaked some commit messages and added some Reviewed-by lines.

* Patch 06/11: Remove copyright line from t7516. Use write_script
  function to write the fake editor.

* Patch 12/11: New commit: consolidate comments for the four reference
  transaction update functions.

This branch is also available in my GitHub account [2] as branch "refs-have-new".

Michael

[1] http://thread.gmane.org/gmane.comp.version-control.git/263522 [2] https://github.com/mhagger/git

Michael Haggerty (12):
  refs: move REF_DELETING to refs.c
  refs: remove the gap in the REF_* constant values
  struct ref_update: move "have_old" into "flags"
  ref_transaction_update(): remove "have_old" parameter
  ref_transaction_delete(): remove "have_old" parameter
  commit: add tests of commit races
  commit: avoid race when creating orphan commits
  ref_transaction_create(): check that new_sha1 is valid
  ref_transaction_delete(): check that old_sha1 is not null_sha1
  ref_transaction_verify(): new function to check a reference's value
  update_ref(): improve documentation
  refs.h: Remove duplication in function docstrings

 branch.c                |   5 +-
 builtin/commit.c        |   4 +-
 builtin/fetch.c         |   6 ++-
 builtin/receive-pack.c  |   5 +-
 builtin/replace.c       |   2 +-
 builtin/tag.c           |   2 +-
 builtin/update-ref.c    |  17 +++----
 fast-import.c           |   6 +--
 refs.c                  | 130 +++++++++++++++++++++++++++++++++---------------
 refs.h                  | 111 ++++++++++++++++++++++++++++-------------
 sequencer.c             |   2 +-
 t/t7516-commit-races.sh |  33 ++++++++++++
 walker.c                |   2 +-
 13 files changed, 227 insertions(+), 98 deletions(-)
 create mode 100755 t/t7516-commit-races.sh