[PATCH 0/7] safer "push --force" with compare-and-swap

[Junio C Hamano <gitster@pobox.com>]

When you have to replace an already published branch with its
rebased version, you would have to --force, but then you risk losing
work, if any, that was pushed by somebody else while you are working
on rebasing, as your earlier decision that replacing the old one
with its rebase is OK was based on the assumption that there is
nothing else going on.  Unfortunately, --force is blind, and did not
offer this "... but fail if the tip has moved from what I expect".

And here is a series to remedy it.  It lets you specify what the
expected current values of refs you are attempting to update, and if
you are lazy, the value is taken from your remote tracking branch
for the ref you are attempting to update.

I am not married to the "lockref" name, but I think the semantics
implemented here is what we discussed to do in the earlier
discussion.

cf. http://thread.gmane.org/gmane.comp.version-control.git/229430

This may still be rough at edges, but a basic testset seems to pass.

I haven't bothered to check the smart-http transport; help is
greatly appreciated.

Junio C Hamano (7):
  cache.h: move remote/connect API out of it
  builtin/push.c: use OPT_BOOL, not OPT_BOOLEAN
  push: beginning of compare-and-swap "force/delete safety"
  remote.c: add command line option parser for --lockref
  push --lockref: implement logic to populate old_sha1_expect[]
  t5533: test "push --lockref"
  push: document --lockref

 Documentation/git-push.txt |  26 +++++++
 builtin/fetch-pack.c       |   2 +
 builtin/push.c             |  18 ++++-
 builtin/receive-pack.c     |   1 +
 builtin/send-pack.c        |  26 +++++++
 cache.h                    |  62 ----------------
 connect.c                  |   1 +
 connect.h                  |  13 ++++
 fetch-pack.c               |   1 +
 fetch-pack.h               |   1 +
 refs.c                     |   8 ---
 remote.c                   | 149 +++++++++++++++++++++++++++++++++++++-
 remote.h                   |  83 +++++++++++++++++++++
 send-pack.c                |   2 +
 t/t5533-push-cas.sh        | 176 +++++++++++++++++++++++++++++++++++++++++++++
 transport-helper.c         |   6 ++
 transport.c                |  13 ++++
 transport.h                |   5 ++
 upload-pack.c              |   1 +
 19 files changed, 519 insertions(+), 75 deletions(-)
 create mode 100644 connect.h
 create mode 100755 t/t5533-push-cas.sh

-- 
1.8.3.2-875-g76c723c