Subject: [PATCH v4] sequencer: rectify empty hint in call of require_clean_work_tree()

From: Oswald Buddenhagen <[email-masked]>
Date: Thu, 24 Aug 2023 17:00:46 +0200

The canonical way to represent "no error hint" is making it NULL, which
shortcuts the error() call altogether. This fixes the output by removing
the line which said just "error:", which would appear when the worktree
is dirtied while editing the initial rebase todo file. This was
introduced by 97e1873 (rebase -i: rewrite complete_action() in C,
2018-08-28), which did a somewhat inaccurate conversion from shell.

To avoid that such bugs re-appear, test for the condition in
require_clean_work_tree().

Signed-off-by: Oswald Buddenhagen <[email-masked]>

---
yeah, so i _did_ miss something.

v4:
- fixed reproduction instructions
v3:
- added BUG()
- rewrote commit message again
v2:
- expanded commit message

Cc: Junio C Hamano <[email-masked]>
---
 sequencer.c | 2 +-
 wt-status.c | 6 +++++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/sequencer.c b/sequencer.c
index cc9821ece2..d15a7409d8 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -6182,7 +6182,7 @@ int complete_action(struct repository *r, struct replay_opts *opts, unsigned fla
 	if (checkout_onto(r, opts, onto_name, &oid, orig_head))
 		goto cleanup;
 
-	if (require_clean_work_tree(r, "rebase", "", 1, 1))
+	if (require_clean_work_tree(r, "rebase", NULL, 1, 1))
 		goto cleanup;
 
 	todo_list_write_total_nr(&new_todo);
diff --git a/wt-status.c b/wt-status.c
index 8a1a4fb1f0..c8c1780566 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -2654,8 +2654,12 @@ int require_clean_work_tree(struct repository *r,
 	}
 
 	if (err) {
-		if (hint)
+		if (hint) {
+			if (!*hint)
+				BUG("empty hint passed to require_clean_work_tree();"
+				    " use NULL instead");
 			error("%s", hint);
+		}
 		if (!gently)
 			exit(128);
 	}
-- 
2.40.0.152.g15d061e6df