[PATCH v4 0/3] push: add "--[no-]force-if-includes"

Add a new option: "--force-if-includes" to "git-push" where forced updates are allowed only if the tip of the remote-tracking ref has been integrated locally, by verifying if the tip of the remote-tracking ref -- on which a local branch has based on -- is reachable from at least one of the "reflog" entries of the branch about to be updated by force on the remote.

This option can be used with "--force-with-lease" with setups where the remote-tracking refs of the repository are implicitly updated in the background to help prevent unintended remote overwrites.

If a local branch is based on a remote ref for a rewrite, and if that remote-tracking ref is updated by a push from another repository after it has been checked out locally, force updating that branch to remote with "--force-with-lease[=<refname>[:<expect>]]" without specifying the "<expect>" value, can cause the update that happened in-between the checkout and forced push to be lost.

Changes since v3:
  - Switch to the two-step approach: check the "reflog" the first
    time to see if the remote ref exists; if not, go through it one
    more time to see if it is reachable (using "in_merge_bases()")
    from any of the entries. This is a necessary step as explained
    here [1].

  - Added back the configuration setting "push.useForceIfIncludes", now
    that it does not affect the functionality of "--force-with-lease"
    when the expected ref is specified.

  - Update "remote-curl" and "send-pack" to recognize the new option;
    this was missing in the previous patches.

  - Broke up the patch-set into medium sized commits.

  - Clean-up unnecessary function calls.

Srinidhi Kaushik (3):
  push: add reflog check for "--force-if-includes"
  push: parse and set flag for "--force-if-includes"
  t, doc: update tests, reference for "--force-if-includes"

 Documentation/config/advice.txt |  9 ++-
 Documentation/config/push.txt   |  5 ++
 Documentation/git-push.txt      | 20 +++++++
 advice.c                        |  3 +
 advice.h                        |  2 +
 builtin/push.c                  | 27 +++++++++
 builtin/send-pack.c             | 11 ++++
 remote-curl.c                   | 14 ++++-
 remote.c                        | 97 ++++++++++++++++++++++++++++++++-
 remote.h                        | 12 +++-
 send-pack.c                     |  1 +
 t/t5533-push-cas.sh             | 53 ++++++++++++++++++
 transport-helper.c              | 11 ++++
 transport.c                     |  8 +++
 transport.h                     | 15 +++--
 15 files changed, 276 insertions(+), 12 deletions(-)

base-commit: 385c171a018f2747b329bcfa6be8eda1709e5abd

[1]: https://public-inbox.org/git/nycvar.QRO.7.76.6.2009161214030.56@tvgsbejvaqbjf.bet/

-- 2.28.0