notes: Don't create (empty) commit when removing non-existing notes

Extend remove_note() in the notes API to return whether or not a note was
actually removed. Use this in 'git notes remove' to skip the creation of
a notes commit when no notes were actually removed.

Also add a test illustrating the change in behavior.

Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 10 insertions, 4 deletions

diff --git a/builtin/notes.c b/builtin/notes.c
index fbc347c9f..6d07aac80 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -769,6 +769,7 @@ static int remove_cmd(int argc, const char **argv, const char *prefix)
 	const char *object_ref;
 	struct notes_tree *t;
 	unsigned char object[20];
+	int retval;
 
 	argc = parse_options(argc, argv, prefix, options,
 			     git_notes_remove_usage, 0);
@@ -785,12 +786,17 @@ static int remove_cmd(int argc, const char **argv, const char *prefix)
 
 	t = init_notes_check("remove");
 
-	fprintf(stderr, "Removing note for object %s\n", sha1_to_hex(object));
-	remove_note(t, object);
+	retval = remove_note(t, object);
+	if (retval)
+		fprintf(stderr, "Object %s has no note\n", sha1_to_hex(object));
+	else {
+		fprintf(stderr, "Removing note for object %s\n",
+			sha1_to_hex(object));
 
-	commit_notes(t, "Notes removed by 'git notes remove'");
+		commit_notes(t, "Notes removed by 'git notes remove'");
+	}
 	free_notes(t);
-	return 0;
+	return retval;
 }
 
 static int prune(int argc, const char **argv, const char *prefix)