Re: [PATCH 4/5] rebase -i: don't fork git checkout

>
> From: Phillip Wood <phillip.wood@dunelm.org.uk>
>
> The "apply" based rebase has avoided forking git checkout since
> ac7f467fef ("builtin/rebase: support running "git rebase <upstream>"",
> 2018-08-07). The code that handles the checkout was moved into libgit
> by b309a97108 ("reset: extract reset_head() from rebase", 2020-04-07)
> so lets start using it for the "merge" based rebase as well. This
> opens the way for us to stop calling the post-checkout hook in the
> future.

> Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
> ---
>  sequencer.c | 29 ++++-------------------------
>  1 file changed, 4 insertions(+), 25 deletions(-)
>
> diff --git a/sequencer.c b/sequencer.c
> index d51440ddcd9..1a9dbc70d3c 100644
> --- a/sequencer.c
> +++ b/sequencer.c
> @@ -4192,42 +4192,21 @@ int apply_autostash_oid(const char *stash_oid)
>         return apply_save_autostash_oid(stash_oid, 1);
>  }
>
> -static int run_git_checkout(struct repository *r, struct replay_opts *opts,
> -                           const char *commit, const char *action)
> -{
> -       struct child_process cmd = CHILD_PROCESS_INIT;
> -       int ret;
> -
> -       cmd.git_cmd = 1;
> -
> -       strvec_push(&cmd.args, "checkout");
> -       strvec_push(&cmd.args, commit);
> -       strvec_pushf(&cmd.env_array, GIT_REFLOG_ACTION "=%s", action);
> -
> -       if (opts->verbose)
> -               ret = run_command(&cmd);
> -       else
> -               ret = run_command_silent_on_success(&cmd);
> -
> -       if (!ret)
> -               discard_index(r->index);
> -
> -       return ret;
> -}
> -
>  static int checkout_onto(struct repository *r, struct replay_opts *opts,
>                          const char *onto_name, const struct object_id *onto,
>                          const struct object_id *orig_head)
>  {
>         const char *action = reflog_message(opts, "start", "checkout %s", onto_name);
>
> -       if (run_git_checkout(r, opts, oid_to_hex(onto), action)) {
> +       if (reset_head(r, onto, "checkout", NULL, RESET_HEAD_DETACH |
> +                      RESET_ORIG_HEAD | RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
> +                      NULL, action, "rebase")) {
>                 apply_autostash(rebase_path_autostash());
>                 sequencer_remove_state(opts);
>                 return error(_("could not detach HEAD"));
>         }
>
> -       return update_ref(NULL, "ORIG_HEAD", orig_head, NULL, 0, UPDATE_REFS_MSG_ON_ERR);
> +       return 0;
>  }
>
>  static int stopped_at_head(struct repository *r)
> --
> gitgitgadget