format_trailer_info(): use trailer_item objects

This is another preparatory refactor to unify the trailer formatters.

Make format_trailer_info() operate on trailer_item objects, not the raw
string array.

We will continue to make improvements, culminating in the renaming of
format_trailer_info() to format_trailers(), at which point the
unification of these formatters will be complete.

In order to avoid breaking t4205 and t6300, flip *_success to *_failure
in the affected test cases. Add a temporary
"test_trailer_option_expect_failure" wrapper which we will use along
with "test_expect_failure" in the next commit to avoid breaking tests.
When the dust settles with the refactors a few more commits later, we
will drop the use of *_failure to make the tests truly pass again.

When the preparatory refactors are complete,
we'll be able to drop the use of *_failure that we introduce here.

Signed-off-by: Linus Arver <linusa@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t4205-log-pretty-formats.sh

@@ -675,7 +675,7 @@ test_expect_success '%(trailers:only=no,only=true) shows only "key: value" trail
 	test_cmp expect actual
 '
 
-test_expect_success '%(trailers:unfold) unfolds trailers' '
+test_expect_failure '%(trailers:unfold) unfolds trailers' '
 	git log --no-walk --pretty="%(trailers:unfold)" >actual &&
 	{
 		unfold <trailers &&
@@ -737,7 +737,7 @@ test_expect_success '%(trailers:key=foo,unfold) properly unfolds' '
 	test_cmp expect actual
 '
 
-test_expect_success 'pretty format %(trailers:key=foo,only=no) also includes nontrailer lines' '
+test_expect_failure 'pretty format %(trailers:key=foo,only=no) also includes nontrailer lines' '
 	git log --no-walk --pretty="format:%(trailers:key=Acked-by,only=no)" >actual &&
 	{
 		echo "Acked-by: A U Thor <author@example.com>" &&
@@ -752,7 +752,7 @@ test_expect_success '%(trailers:key) without value is error' '
 	test_cmp expect actual
 '
 
-test_expect_success '%(trailers:keyonly) shows only keys' '
+test_expect_failure '%(trailers:keyonly) shows only keys' '
 	git log --no-walk --pretty="format:%(trailers:keyonly)" >actual &&
 	test_write_lines \
 		"Signed-off-by" \
@@ -774,7 +774,7 @@ test_expect_success '%(trailers:key=foo,valueonly) shows only value' '
 	test_cmp expect actual
 '
 
-test_expect_success '%(trailers:valueonly) shows only values' '
+test_expect_failure '%(trailers:valueonly) shows only values' '
 	git log --no-walk --pretty="format:%(trailers:valueonly)" >actual &&
 	test_write_lines \
 		"A U Thor <author@example.com>" \
@@ -813,7 +813,7 @@ test_expect_success 'pretty format %(trailers:separator=X,unfold) changes separa
 	test_cmp expect actual
 '
 
-test_expect_success 'pretty format %(trailers:key_value_separator) changes key-value separator' '
+test_expect_failure 'pretty format %(trailers:key_value_separator) changes key-value separator' '
 	git log --no-walk --pretty=format:"X%(trailers:key_value_separator=%x00)X" >actual &&
 	(
 		printf "XSigned-off-by\0A U Thor <author@example.com>\n" &&
@@ -824,7 +824,7 @@ test_expect_success 'pretty format %(trailers:key_value_separator) changes key-v
 	test_cmp expect actual
 '
 
-test_expect_success 'pretty format %(trailers:key_value_separator,unfold) changes key-value separator' '
+test_expect_failure 'pretty format %(trailers:key_value_separator,unfold) changes key-value separator' '
 	git log --no-walk --pretty=format:"X%(trailers:key_value_separator=%x00,unfold)X" >actual &&
 	(
 		printf "XSigned-off-by\0A U Thor <author@example.com>\n" &&

t/t6300-for-each-ref.sh

@@ -1446,7 +1446,19 @@ test_trailer_option () {
 	'
 }
 
-test_trailer_option '%(trailers:unfold) unfolds trailers' \
+# Just like test_trailer_option, but expect failure instead of success.
+test_trailer_option_expect_failure () {
+	title=$1 option=$2
+	cat >expect
+	test_expect_failure "$title" '
+		git for-each-ref --format="%($option)" refs/heads/main >actual &&
+		test_cmp expect actual &&
+		git for-each-ref --format="%(contents:$option)" refs/heads/main >actual &&
+		test_cmp expect actual
+	'
+}
+
+test_trailer_option_expect_failure '%(trailers:unfold) unfolds trailers' \
 	'trailers:unfold' <<-EOF
 	$(unfold <trailers)
 
@@ -1530,7 +1542,7 @@ test_trailer_option '%(trailers:key=foo,unfold) properly unfolds' \
 
 	EOF
 
-test_trailer_option '%(trailers:key=foo,only=no) also includes nontrailer lines' \
+test_trailer_option_expect_failure '%(trailers:key=foo,only=no) also includes nontrailer lines' \
 	'trailers:key=Signed-off-by,only=no' <<-EOF
 	Signed-off-by: A U Thor <author@example.com>
 	$(grep patch.description <trailers)

trailer.c

@@ -1085,21 +1085,21 @@ void trailer_info_release(struct trailer_info *info)
 }
 
 static void format_trailer_info(const struct process_trailer_options *opts,
-				const struct trailer_info *info,
+				struct list_head *trailers,
 				struct strbuf *out)
 {
 	size_t origlen = out->len;
-	size_t i;
+	struct list_head *pos;
+	struct trailer_item *item;
 
-	for (i = 0; i < info->trailer_nr; i++) {
+	list_for_each(pos, trailers) {
-		char *trailer = info->trailers[i];
+		item = list_entry(pos, struct trailer_item, list);
-		ssize_t separator_pos = find_separator(trailer, separators);
+		if (item->token) {
-
-		if (separator_pos >= 1) {
 			struct strbuf tok = STRBUF_INIT;
 			struct strbuf val = STRBUF_INIT;
+			strbuf_addstr(&tok, item->token);
+			strbuf_addstr(&val, item->value);
 
-			parse_trailer(&tok, &val, NULL, trailer, separator_pos);
 			if (!opts->filter || opts->filter(&tok, opts->filter_data)) {
 				if (opts->unfold)
 					unfold_value(&val);
@@ -1126,13 +1126,12 @@ static void format_trailer_info(const struct process_trailer_options *opts,
 			if (opts->separator && out->len != origlen) {
 				strbuf_addbuf(out, opts->separator);
 			}
-			strbuf_addstr(out, trailer);
+			strbuf_addstr(out, item->value);
 			if (opts->separator) {
 				strbuf_rtrim(out);
 			}
 		}
 	}
-
 }
 
 void format_trailers_from_commit(const struct process_trailer_options *opts,
@@ -1151,7 +1150,7 @@ void format_trailers_from_commit(const struct process_trailer_options *opts,
 		strbuf_add(out, msg + info.trailer_block_start,
 			   info.trailer_block_end - info.trailer_block_start);
 	} else
-		format_trailer_info(opts, &info, out);
+		format_trailer_info(opts, &trailer_objects, out);
 
 	free_trailers(&trailer_objects);
 	trailer_info_release(&info);