[PATCH 11/15] sequencer: lib'ify save_todo()

[Johannes Schindelin <johannes.schindelin@gmx.de>]

To be truly useful, the sequencer should never die() but always return
an error.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 sequencer.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/sequencer.c b/sequencer.c
index 3e07aa0..17f2c8b 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -929,24 +929,29 @@ static int sequencer_rollback(struct replay_opts *opts)
 	return -1;
 }
 
-static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
+static int save_todo(struct commit_list *todo_list, struct replay_opts *opts)
 {
 	static struct lock_file todo_lock;
 	struct strbuf buf = STRBUF_INIT;
 	int fd;
 
-	fd = hold_lock_file_for_update(&todo_lock, git_path_todo_file(), LOCK_DIE_ON_ERROR);
+	fd = hold_lock_file_for_update(&todo_lock, git_path_todo_file(), 0);
+	if (fd < 0)
+		return error_errno(_("Could not lock '%s'"),
+				   git_path_todo_file());
 	if (format_todo(&buf, todo_list, opts) < 0)
-		die(_("Could not format %s."), git_path_todo_file());
+		return error(_("Could not format %s."), git_path_todo_file());
 	if (write_in_full(fd, buf.buf, buf.len) < 0) {
 		strbuf_release(&buf);
-		die_errno(_("Could not write to %s"), git_path_todo_file());
+		return error_errno(_("Could not write to %s"),
+				   git_path_todo_file());
 	}
 	if (commit_lock_file(&todo_lock) < 0) {
 		strbuf_release(&buf);
-		die(_("Error wrapping up %s."), git_path_todo_file());
+		return error(_("Error wrapping up %s."), git_path_todo_file());
 	}
 	strbuf_release(&buf);
+	return 0;
 }
 
 static void save_opts(struct replay_opts *opts)
@@ -995,7 +1000,8 @@ static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
 		return -1;
 
 	for (cur = todo_list; cur; cur = cur->next) {
-		save_todo(cur, opts);
+		if (save_todo(cur, opts))
+			return -1;
 		res = do_pick_commit(cur->item, opts);
 		if (res)
 			return res;
-- 
2.10.0.rc1.99.gcd66998