[PATCH 01/15] sequencer: lib'ify write_message()

[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 | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/sequencer.c b/sequencer.c
index 2e9c7d0..c75296c 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -180,17 +180,20 @@ static void print_advice(int show_hint, struct replay_opts *opts)
 	}
 }
 
-static void write_message(struct strbuf *msgbuf, const char *filename)
+static int write_message(struct strbuf *msgbuf, const char *filename)
 {
 	static struct lock_file msg_file;
 
-	int msg_fd = hold_lock_file_for_update(&msg_file, filename,
-					       LOCK_DIE_ON_ERROR);
+	int msg_fd = hold_lock_file_for_update(&msg_file, filename, 0);
+	if (msg_fd < 0)
+		return error_errno(_("Could not lock '%s'"), filename);
 	if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
-		die_errno(_("Could not write to %s"), filename);
+		return error_errno(_("Could not write to %s"), filename);
 	strbuf_release(msgbuf);
 	if (commit_lock_file(&msg_file) < 0)
-		die(_("Error wrapping up %s."), filename);
+		return error(_("Error wrapping up %s."), filename);
+
+	return 0;
 }
 
 static struct tree *empty_tree(void)
@@ -564,16 +567,16 @@ static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
 					 head, &msgbuf, opts);
 		if (res < 0)
 			return res;
-		write_message(&msgbuf, git_path_merge_msg());
+		res |= write_message(&msgbuf, git_path_merge_msg());
 	} else {
 		struct commit_list *common = NULL;
 		struct commit_list *remotes = NULL;
 
-		write_message(&msgbuf, git_path_merge_msg());
+		res = write_message(&msgbuf, git_path_merge_msg());
 
 		commit_list_insert(base, &common);
 		commit_list_insert(next, &remotes);
-		res = try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
+		res |= try_merge_command(opts->strategy, opts->xopts_nr, opts->xopts,
 					common, sha1_to_hex(head), remotes);
 		free_commit_list(common);
 		free_commit_list(remotes);
-- 
2.10.0.rc1.99.gcd66998