[PATCH 3/5] ref-filter: factor out "unrecognized %(foo) arg" errors

[Jeff King <peff@peff.net>]

Atom parsers that take arguments generally have a catch-all for "this
arg is not recognized". Most of them use the same printf template, which
is good, because it makes life easier for translators. Let's pull this
template into a helper function, which makes the code in the parsers
shorter and avoids any possibility of differences.

As with the previous commit, we'll pick an arbitrary atom to make sure
the test suite covers this code.

Signed-off-by: Jeff King <peff@peff.net>
---
 ref-filter.c            | 16 +++++++++++-----
 t/t6300-for-each-ref.sh |  6 ++++++
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/ref-filter.c b/ref-filter.c
index 639b18ab36..271d619da9 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -234,6 +234,12 @@ static int err_no_arg(struct strbuf *sb, const char *name)
 	return -1;
 }
 
+static int err_bad_arg(struct strbuf *sb, const char *name, const char *arg)
+{
+	strbuf_addf(sb, _("unrecognized %%(%s) argument: %s"), name, arg);
+	return -1;
+}
+
 static int color_atom_parser(struct ref_format *format, struct used_atom *atom,
 			     const char *color_value, struct strbuf *err)
 {
@@ -347,7 +353,7 @@ static int objectsize_atom_parser(struct ref_format *format, struct used_atom *a
 		else
 			oi.info.disk_sizep = &oi.disk_size;
 	} else
-		return strbuf_addf_ret(err, -1, _("unrecognized %%(%s) argument: %s"), "objectsize", arg);
+		return err_bad_arg(err, "objectsize", arg);
 	return 0;
 }
 
@@ -380,7 +386,7 @@ static int subject_atom_parser(struct ref_format *format, struct used_atom *atom
 	else if (!strcmp(arg, "sanitize"))
 		atom->u.contents.option = C_SUB_SANITIZE;
 	else
-		return strbuf_addf_ret(err, -1, _("unrecognized %%(%s) argument: %s"), "subject", arg);
+		return err_bad_arg(err, "subject", arg);
 	return 0;
 }
 
@@ -434,7 +440,7 @@ static int contents_atom_parser(struct ref_format *format, struct used_atom *ato
 		if (strtoul_ui(arg, 10, &atom->u.contents.nlines))
 			return strbuf_addf_ret(err, -1, _("positive value expected contents:lines=%s"), arg);
 	} else
-		return strbuf_addf_ret(err, -1, _("unrecognized %%(%s) argument: %s"), "contents", arg);
+		return err_bad_arg(err, "contents", arg);
 	return 0;
 }
 
@@ -446,7 +452,7 @@ static int raw_atom_parser(struct ref_format *format, struct used_atom *atom,
 	else if (!strcmp(arg, "size"))
 		atom->u.raw_data.option = RAW_LENGTH;
 	else
-		return strbuf_addf_ret(err, -1, _("unrecognized %%(%s) argument: %s"), "raw", arg);
+		return err_bad_arg(err, "raw", arg);
 	return 0;
 }
 
@@ -563,7 +569,7 @@ static int if_atom_parser(struct ref_format *format, struct used_atom *atom,
 	} else if (skip_prefix(arg, "notequals=", &atom->u.if_then_else.str)) {
 		atom->u.if_then_else.cmp_status = COMPARE_UNEQUAL;
 	} else
-		return strbuf_addf_ret(err, -1, _("unrecognized %%(%s) argument: %s"), "if", arg);
+		return err_bad_arg(err, "if", arg);
 	return 0;
 }
 
diff --git a/t/t6300-for-each-ref.sh b/t/t6300-for-each-ref.sh
index 8d99658ef8..010ba5a2cb 100755
--- a/t/t6300-for-each-ref.sh
+++ b/t/t6300-for-each-ref.sh
@@ -1248,6 +1248,12 @@ test_expect_success 'HEAD atom does not take arguments' '
 	test_cmp expect err
 '
 
+test_expect_success 'subject atom rejects unknown arguments' '
+	test_must_fail git for-each-ref --format="%(subject:foo)" 2>err &&
+	echo "fatal: unrecognized %(subject) argument: foo" >expect &&
+	test_cmp expect err
+'
+
 test_expect_success 'trailer parsing not fooled by --- line' '
 	git commit --allow-empty -F - <<-\EOF &&
 	this is the subject
-- 
2.39.0.550.g5015380a67