Re: [PATCH 11/11] builtin rebase: support `git rebase <upstream> <switch-to>`

>
> This commit adds support for `switch-to` which is used to switch to the
> target branch if needed. The equivalent codes found in shell script
> `git-legacy-rebase.sh` is converted to builtin `rebase.c`.
>
> Signed-off-by: Pratik Karki <predatoramigo@gmail.com>
> ---
>  builtin/rebase.c | 48 ++++++++++++++++++++++++++++++++++++++++++++----
>  1 file changed, 44 insertions(+), 4 deletions(-)
>
> diff --git a/builtin/rebase.c b/builtin/rebase.c
> index 63634210c0..b2ddfa8dbf 100644
> --- a/builtin/rebase.c
> +++ b/builtin/rebase.c
> @@ -79,6 +79,7 @@ struct rebase_options {
>         struct commit *onto;
>         const char *onto_name;
>         const char *revisions;
> +       const char *switch_to;
>         int root;
>         struct commit *restrict_revision;
>         int dont_finish_rebase;
> @@ -186,6 +187,8 @@ static int run_specific_rebase(struct rebase_options *opts)
>                 opts->flags & REBASE_DIFFSTAT ? "t" : "");
>         add_var(&script_snippet, "force_rebase",
>                 opts->flags & REBASE_FORCE ? "t" : "");
> +       if (opts->switch_to)
> +               add_var(&script_snippet, "switch_to", opts->switch_to);
>
>         switch (opts->type) {
>         case REBASE_AM:
> @@ -564,9 +567,23 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
>          * orig_head -- commit object name of tip of the branch before rebasing
>          * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
>          */
> -       if (argc > 0)
> -                die("TODO: handle switch_to");
> -       else {
> +       if (argc == 1) {
> +               /* Is it "rebase other branchname" or "rebase other commit"? */
> +               branch_name = argv[0];
> +               options.switch_to = argv[0];
> +
> +               /* Is it a local branch? */
> +               strbuf_reset(&buf);
> +               strbuf_addf(&buf, "refs/heads/%s", branch_name);
> +               if (!read_ref(buf.buf, &options.orig_head))
> +                       options.head_name = xstrdup(buf.buf);
> +               /* If not is it a valid ref (branch or commit)? */
> +               else if (!get_oid(branch_name, &options.orig_head))
> +                       options.head_name = NULL;
> +               else
> +                       die(_("fatal: no such branch/commit '%s'"),

> +                           branch_name);
> +       } else if (argc == 0) {
>                 /* Do not need to switch branches, we are already on it. */
>                 options.head_name =
>                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
> @@ -585,7 +602,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
>                 }
>                 if (get_oid("HEAD", &options.orig_head))
>                         die(_("Could not resolve HEAD to a revision"));
> -       }
> +       } else
> +               BUG("unexpected number of arguments left to parse");