Re: [PATCH v3 3/6] commit: add a reword suboption to --fixup

`git commit --fixup=reword:<commit>` creates an empty "amend!" commit
that will reword <commit> without changing its contents when it is
rebased with --autosquash.

Apart from ignoring staged changes it works similarly to
`--fixup=amend:<commit>`.

Mentored-by: Christian Couder [off-list ref]
Mentored-by: Phillip Wood [off-list ref]
Helped-by: Junio C Hamano [off-list ref]
Signed-off-by: Charvi Mendiratta <redacted>
---
 builtin/commit.c | 44 ++++++++++++++++++++++++++++++++++++--------
 1 file changed, 36 insertions(+), 8 deletions(-)

diff --git a/builtin/commit.c b/builtin/commit.c
index 200ef83cc0..a4d18d96df 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c

@@ -1186,6 +1186,27 @@ static void finalize_deferred_config(struct wt_status *s)
 		s->ahead_behind_flags = AHEAD_BEHIND_FULL;
 }

+static void check_fixup_reword_options(int argc, const char *argv[]) {
+	if (whence != FROM_COMMIT) {
+		if (whence == FROM_MERGE)
+			die(_("You are in the middle of a merge -- cannot reword."));
+		else if (is_from_cherry_pick(whence))
+			die(_("You are in the middle of a cherry-pick -- cannot reword."));
+	}
+	if (argc)
+		die(_("cannot combine reword option of --fixup with path %s"), *argv);