notes remove: --ignore-missing

Depending on the application, it is not necessarily an error for an object
to lack a note, especially if the only thing the caller wants to make sure
is that notes are cleared for an object.  By passing this option from the
command line, the "git notes remove" command considers it a success if the
object did not have any note to begin with.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-notes.txt

@@ -17,7 +17,7 @@ SYNOPSIS
 'git notes' merge [-v | -q] [-s <strategy> ] <notes_ref>
 'git notes' merge --commit [-v | -q]
 'git notes' merge --abort [-v | -q]
-'git notes' remove [<object>...]
+'git notes' remove [--ignore-missing] [<object>...]
 'git notes' prune [-n | -v]
 'git notes' get-ref
 
@@ -155,6 +155,10 @@ OPTIONS
 	'GIT_NOTES_REF' and the "core.notesRef" configuration.  The ref
 	is taken to be in `refs/notes/` if it is not qualified.
 
+--ignore-missing::
+	Do not consider it an error to request removing notes from an
+	object that does not have notes attached to it.
+
 -n::
 --dry-run::
 	Do not remove anything; just report the object names whose notes

builtin/notes.c

@@ -953,7 +953,9 @@ static int merge(int argc, const char **argv, const char *prefix)
 	return result < 0; /* return non-zero on conflicts */
 }
 
-static int remove_one_note(struct notes_tree *t, const char *name)
+#define MISSING_OK 1
+
+static int remove_one_note(struct notes_tree *t, const char *name, unsigned flag)
 {
 	int status;
 	unsigned char sha1[20];
@@ -964,12 +966,16 @@ static int remove_one_note(struct notes_tree *t, const char *name)
 		fprintf(stderr, _("Object %s has no note\n"), name);
 	else
 		fprintf(stderr, _("Removing note for object %s\n"), name);
-	return status;
+	return (flag & MISSING_OK) ? 0 : status;
 }
 
 static int remove_cmd(int argc, const char **argv, const char *prefix)
 {
+	unsigned flag = 0;
 	struct option options[] = {
+		OPT_BIT(0, "ignore-missing", &flag,
+			"attempt to remove non-existent note is not an error",
+			MISSING_OK),
 		OPT_END()
 	};
 	struct notes_tree *t;
@@ -981,10 +987,10 @@ static int remove_cmd(int argc, const char **argv, const char *prefix)
 	t = init_notes_check("remove");
 
 	if (!argc) {
-		retval = remove_one_note(t, "HEAD");
+		retval = remove_one_note(t, "HEAD", flag);
 	} else {
 		while (*argv) {
-			retval |= remove_one_note(t, *argv);
+			retval |= remove_one_note(t, *argv, flag);
 			argv++;
 		}
 	}

t/t3301-notes.sh

@@ -455,6 +455,26 @@ test_expect_success 'removing is atomic' '
 	test "$before" = "$after"
 '
 
+test_expect_success 'removing with --ignore-missing' '
+	before=$(git rev-parse --verify refs/notes/commits) &&
+	test_when_finished "git update-ref refs/notes/commits $before" &&
+
+	# We have only two -- add another and make sure it stays
+	git notes add -m "extra" &&
+	git notes list HEAD >after-removal-expect &&
+	git notes remove --ignore-missing HEAD^^ HEAD^^^ HEAD^ &&
+	git notes list | sed -e "s/ .*//" >actual &&
+	test_cmp after-removal-expect actual
+'
+
+test_expect_success 'removing with --ignore-missing but bogus ref' '
+	before=$(git rev-parse --verify refs/notes/commits) &&
+	test_when_finished "git update-ref refs/notes/commits $before" &&
+	test_must_fail git notes remove --ignore-missing HEAD^^ HEAD^^^ NO-SUCH-COMMIT &&
+	after=$(git rev-parse --verify refs/notes/commits) &&
+	test "$before" = "$after"
+'
+
 test_expect_success 'list notes with "git notes list"' '
 	git notes list > output &&
 	test_cmp expect output