sequencer (rebase -i): allow fast-forwarding for edit/reword

The sequencer already knew how to fast-forward instead of
cherry-picking, if possible.

We want to continue to do this, of course, but in case of the 'reword'
command, we will need to call `git commit` after fast-forwarding.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 17 insertions, 8 deletions

diff --git a/sequencer.c b/sequencer.c
index 50e998acc4..23161f593e 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -860,7 +860,7 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
 	const char *base_label, *next_label;
 	struct commit_message msg = { NULL, NULL, NULL, NULL };
 	struct strbuf msgbuf = STRBUF_INIT;
-	int res, unborn = 0, amend = 0, allow;
+	int res, unborn = 0, amend = 0, allow = 0;
 
 	if (opts->no_commit) {
 		/*
@@ -905,11 +905,23 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
 	else
 		parent = commit->parents->item;
 
+	if (get_message(commit, &msg) != 0)
+		return error(_("cannot get commit message for %s"),
+			oid_to_hex(&commit->object.oid));
+
 	if (opts->allow_ff && !is_fixup(command) &&
 	    ((parent && !hashcmp(parent->object.oid.hash, head)) ||
-	     (!parent && unborn)))
-		return fast_forward_to(commit->object.oid.hash, head, unborn, opts);
-
+	     (!parent && unborn))) {
+		if (is_rebase_i(opts))
+			write_author_script(msg.message);
+		res = fast_forward_to(commit->object.oid.hash, head, unborn,
+			opts);
+		if (res || command != TODO_REWORD)
+			goto leave;
+		edit = amend = 1;
+		msg_file = NULL;
+		goto fast_forward_edit;
+	}
 	if (parent && parse_commit(parent) < 0)
 		/* TRANSLATORS: The first %s will be a "todo" command like
 		   "revert" or "pick", the second %s a SHA1. */
@@ -917,10 +929,6 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
 			command_to_string(command),
 			oid_to_hex(&parent->object.oid));
 
-	if (get_message(commit, &msg) != 0)
-		return error(_("cannot get commit message for %s"),
-			oid_to_hex(&commit->object.oid));
-
 	/*
 	 * "commit" is an existing commit.  We would want to apply
 	 * the difference it introduces since its first parent "prev"
@@ -1044,6 +1052,7 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
 		goto leave;
 	}
 	if (!opts->no_commit)
+fast_forward_edit:
 		res = run_git_commit(msg_file, opts, allow, edit, amend,
 				     cleanup_commit_message);