[GSoC][PATCH v4 0/3] rebase -i: rewrite reflog operations in C

This patch series rewrites the reflog operations from shell to C. This is part of the effort to rewrite interactive rebase in C.

The first commit is dedicated to creating a function to silence a command, as the sequencer will do in several places with these patches.

This branch is based on ag/rebase-i-rewrite-todo, and does not conflict with pu (as of 2018-06-25).

Changes since v3:

 - Removing a comment from run_command_silent_on_success()

 - Changing the order of setup_reflog_action() and checkout_onto()
   rewrites in the series

 - Renaming checkout_onto() to detach_onto()

 - Renaming checkout_base_commit() (rewrite of setup_reflog_action()) to
   checkout_onto()

 - Using the `else` keyword to call run_command_silent_on_success() or
   run_command() in run_git_commit() and run_git_checkout().

Alban Gruin (3):
  sequencer: extract a function to silence a command, except if it fails
  rebase -i: rewrite checkout_onto() in C
  rebase -i: rewrite setup_reflog_action() in C

 builtin/rebase--helper.c   |  13 ++++-
 git-rebase--interactive.sh |  28 ++--------
 sequencer.c                | 101 +++++++++++++++++++++++++++----------
 sequencer.h                |   6 +++
 4 files changed, 97 insertions(+), 51 deletions(-)