Merge branch 'hv/trailer-formatting'

The logic to handle "trailer" related placeholders in the
"--format=" mechanisms in the "log" family and "for-each-ref"
family is getting unified.

* hv/trailer-formatting:
  ref-filter: use pretty.c logic for trailers
  pretty.c: capture invalid trailer argument
  pretty.c: refactor trailer logic to `format_set_trailers_options()`
  t6300: use function to test trailer options

5 files changed, 236 insertions, 103 deletions

diff --git a/Documentation/git-for-each-ref.txt b/Documentation/git-for-each-ref.txt
index 2962f85a50..2ae2478de7 100644
--- a/Documentation/git-for-each-ref.txt
+++ b/Documentation/git-for-each-ref.txt
@@ -260,11 +260,9 @@ contents:lines=N::
 	The first `N` lines of the message.
 
 Additionally, the trailers as interpreted by linkgit:git-interpret-trailers[1]
-are obtained as `trailers` (or by using the historical alias
-`contents:trailers`).  Non-trailer lines from the trailer block can be omitted
-with `trailers:only`. Whitespace-continuations can be removed from trailers so
-that each trailer appears on a line by itself with its full content with
-`trailers:unfold`. Both can be used together as `trailers:unfold,only`.
+are obtained as `trailers[:options]` (or by using the historical alias
+`contents:trailers[:options]`). For valid [:option] values see `trailers`
+section of linkgit:git-log[1].
 
 For sorting purposes, fields with numeric values sort in numeric order
 (`objectsize`, `authordate`, `committerdate`, `creatordate`, `taggerdate`).
diff --git a/pretty.c b/pretty.c
index b4ff3f602f..c5f5ecc40d 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1149,6 +1149,63 @@ static int format_trailer_match_cb(const struct strbuf *key, void *ud)
 	return 0;
 }
 
+int format_set_trailers_options(struct process_trailer_options *opts,
+				struct string_list *filter_list,
+				struct strbuf *sepbuf,
+				struct strbuf *kvsepbuf,
+				const char **arg,
+				char **invalid_arg)
+{
+	for (;;) {
+		const char *argval;
+		size_t arglen;
+
+		if (**arg == ')')
+			break;
+
+		if (match_placeholder_arg_value(*arg, "key", arg, &argval, &arglen)) {
+			uintptr_t len = arglen;
+
+			if (!argval)
+				return -1;
+
+			if (len && argval[len - 1] == ':')
+				len--;
+			string_list_append(filter_list, argval)->util = (char *)len;
+
+			opts->filter = format_trailer_match_cb;
+			opts->filter_data = filter_list;
+			opts->only_trailers = 1;
+		} else if (match_placeholder_arg_value(*arg, "separator", arg, &argval, &arglen)) {
+			char *fmt;
+
+			strbuf_reset(sepbuf);
+			fmt = xstrndup(argval, arglen);
+			strbuf_expand(sepbuf, fmt, strbuf_expand_literal_cb, NULL);
+			free(fmt);
+			opts->separator = sepbuf;
+		} else if (match_placeholder_arg_value(*arg, "key_value_separator", arg, &argval, &arglen)) {
+			char *fmt;
+
+			strbuf_reset(kvsepbuf);
+			fmt = xstrndup(argval, arglen);
+			strbuf_expand(kvsepbuf, fmt, strbuf_expand_literal_cb, NULL);
+			free(fmt);
+			opts->key_value_separator = kvsepbuf;
+		} else if (!match_placeholder_bool_arg(*arg, "only", arg, &opts->only_trailers) &&
+			   !match_placeholder_bool_arg(*arg, "unfold", arg, &opts->unfold) &&
+			   !match_placeholder_bool_arg(*arg, "keyonly", arg, &opts->key_only) &&
+			   !match_placeholder_bool_arg(*arg, "valueonly", arg, &opts->value_only)) {
+			if (invalid_arg) {
+				size_t len = strcspn(*arg, ",)");
+				*invalid_arg = xstrndup(*arg, len);
+			}
+			return -1;
+		}
+	}
+	return 0;
+}
+
 static size_t format_commit_one(struct strbuf *sb, /* in UTF-8 */
 				const char *placeholder,
 				void *context)
@@ -1429,45 +1486,8 @@ static size_t format_commit_one(struct strbuf *sb, /* in UTF-8 */
 
 		if (*arg == ':') {
 			arg++;
-			for (;;) {
-				const char *argval;
-				size_t arglen;
-
-				if (match_placeholder_arg_value(arg, "key", &arg, &argval, &arglen)) {
-					uintptr_t len = arglen;
-
-					if (!argval)
-						goto trailer_out;
-
-					if (len && argval[len - 1] == ':')
-						len--;
-					string_list_append(&filter_list, argval)->util = (char *)len;
-
-					opts.filter = format_trailer_match_cb;
-					opts.filter_data = &filter_list;
-					opts.only_trailers = 1;
-				} else if (match_placeholder_arg_value(arg, "separator", &arg, &argval, &arglen)) {
-					char *fmt;
-
-					strbuf_reset(&sepbuf);
-					fmt = xstrndup(argval, arglen);
-					strbuf_expand(&sepbuf, fmt, strbuf_expand_literal_cb, NULL);
-					free(fmt);
-					opts.separator = &sepbuf;
-				} else if (match_placeholder_arg_value(arg, "key_value_separator", &arg, &argval, &arglen)) {
-					char *fmt;
-
-					strbuf_reset(&kvsepbuf);
-					fmt = xstrndup(argval, arglen);
-					strbuf_expand(&kvsepbuf, fmt, strbuf_expand_literal_cb, NULL);
-					free(fmt);
-					opts.key_value_separator = &kvsepbuf;
-				} else if (!match_placeholder_bool_arg(arg, "only", &arg, &opts.only_trailers) &&
-					   !match_placeholder_bool_arg(arg, "unfold", &arg, &opts.unfold) &&
-					   !match_placeholder_bool_arg(arg, "keyonly", &arg, &opts.key_only) &&
-					   !match_placeholder_bool_arg(arg, "valueonly", &arg, &opts.value_only))
-					break;
-			}
+			if (format_set_trailers_options(&opts, &filter_list, &sepbuf, &kvsepbuf, &arg, NULL))
+				goto trailer_out;
 		}
 		if (*arg == ')') {
 			format_trailers_from_commit(sb, msg + c->subject_off, &opts);
diff --git a/pretty.h b/pretty.h
index 7ce6c0b437..d902cdd70a 100644
--- a/pretty.h
+++ b/pretty.h
@@ -6,6 +6,7 @@
 
 struct commit;
 struct strbuf;
+struct process_trailer_options;
 
 /* Commit formats */
 enum cmit_fmt {
@@ -142,4 +143,15 @@ int commit_format_is_empty(enum cmit_fmt);
 /* Make subject of commit message suitable for filename */
 void format_sanitized_subject(struct strbuf *sb, const char *msg, size_t len);
 
+/*
+ * Set values of fields in "struct process_trailer_options"
+ * according to trailers arguments.
+ */
+int format_set_trailers_options(struct process_trailer_options *opts,
+			struct string_list *filter_list,
+			struct strbuf *sepbuf,
+			struct strbuf *kvsepbuf,
+			const char **arg,
+			char **invalid_arg);
+
 #endif /* PRETTY_H */
diff --git a/ref-filter.c b/ref-filter.c
index bade6528ee..e84efb53db 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -67,6 +67,12 @@ struct refname_atom {
 	int lstrip, rstrip;
 };
 
+static struct ref_trailer_buf {
+	struct string_list filter_list;
+	struct strbuf sepbuf;
+	struct strbuf kvsepbuf;
+} ref_trailer_buf = {STRING_LIST_INIT_NODUP, STRBUF_INIT, STRBUF_INIT};
+
 static struct expand_data {
 	struct object_id oid;
 	enum object_type type;
@@ -313,28 +319,26 @@ static int subject_atom_parser(const struct ref_format *format, struct used_atom
 static int trailers_atom_parser(const struct ref_format *format, struct used_atom *atom,
 				const char *arg, struct strbuf *err)
 {
-	struct string_list params = STRING_LIST_INIT_DUP;
-	int i;
-
 	atom->u.contents.trailer_opts.no_divider = 1;
 
 	if (arg) {
-		string_list_split(&params, arg, ',', -1);
-		for (i = 0; i < params.nr; i++) {
-			const char *s = params.items[i].string;
-			if (!strcmp(s, "unfold"))
-				atom->u.contents.trailer_opts.unfold = 1;
-			else if (!strcmp(s, "only"))
-				atom->u.contents.trailer_opts.only_trailers = 1;
-			else {
-				strbuf_addf(err, _("unknown %%(trailers) argument: %s"), s);
-				string_list_clear(&params, 0);
-				return -1;
-			}
+		const char *argbuf = xstrfmt("%s)", arg);
+		char *invalid_arg = NULL;
+
+		if (format_set_trailers_options(&atom->u.contents.trailer_opts,
+		    &ref_trailer_buf.filter_list,
+		    &ref_trailer_buf.sepbuf,
+		    &ref_trailer_buf.kvsepbuf,
+		    &argbuf, &invalid_arg)) {
+			if (!invalid_arg)
+				strbuf_addf(err, _("expected %%(trailers:key=<value>)"));
+			else
+				strbuf_addf(err, _("unknown %%(trailers) argument: %s"), invalid_arg);
+			free((char *)invalid_arg);
+			return -1;
 		}
 	}
 	atom->u.contents.option = C_TRAILERS;
-	string_list_clear(&params, 0);
 	return 0;
 }
 
diff --git a/t/t6300-for-each-ref.sh b/t/t6300-for-each-ref.sh
index ca62e764b5..cac7f443d0 100755
--- a/t/t6300-for-each-ref.sh
+++ b/t/t6300-for-each-ref.sh
@@ -814,53 +814,152 @@ test_expect_success 'set up trailers for next test' '
 	EOF
 '
 
-test_expect_success '%(trailers:unfold) unfolds trailers' '
-	{
-		unfold <trailers
-		echo
-	} >expect &&
-	git for-each-ref --format="%(trailers:unfold)" refs/heads/main >actual &&
-	test_cmp expect actual &&
-	git for-each-ref --format="%(contents:trailers:unfold)" refs/heads/main >actual &&
-	test_cmp expect actual
-'
+test_trailer_option () {
+	title=$1 option=$2
+	cat >expect
+	test_expect_success "$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_expect_success '%(trailers:only) shows only "key: value" trailers' '
-	{
-		grep -v patch.description <trailers &&
-		echo
-	} >expect &&
-	git for-each-ref --format="%(trailers:only)" refs/heads/main >actual &&
-	test_cmp expect actual &&
-	git for-each-ref --format="%(contents:trailers:only)" refs/heads/main >actual &&
-	test_cmp expect actual
-'
+test_trailer_option '%(trailers:unfold) unfolds trailers' \
+	'trailers:unfold' <<-EOF
+	$(unfold <trailers)
 
-test_expect_success '%(trailers:only) and %(trailers:unfold) work together' '
-	{
-		grep -v patch.description <trailers | unfold &&
-		echo
-	} >expect &&
-	git for-each-ref --format="%(trailers:only,unfold)" refs/heads/main >actual &&
-	test_cmp expect actual &&
-	git for-each-ref --format="%(trailers:unfold,only)" refs/heads/main >actual &&
-	test_cmp actual actual &&
-	git for-each-ref --format="%(contents:trailers:only,unfold)" refs/heads/main >actual &&
-	test_cmp expect actual &&
-	git for-each-ref --format="%(contents:trailers:unfold,only)" refs/heads/main >actual &&
-	test_cmp actual actual
-'
-
-test_expect_success '%(trailers) rejects unknown trailers arguments' '
-	# error message cannot be checked under i18n
-	cat >expect <<-EOF &&
+	EOF
+
+test_trailer_option '%(trailers:only) shows only "key: value" trailers' \
+	'trailers:only' <<-EOF
+	$(grep -v patch.description <trailers)
+
+	EOF
+
+test_trailer_option '%(trailers:only=no,only=true) shows only "key: value" trailers' \
+	'trailers:only=no,only=true' <<-EOF
+	$(grep -v patch.description <trailers)
+
+	EOF
+
+test_trailer_option '%(trailers:only=yes) shows only "key: value" trailers' \
+	'trailers:only=yes' <<-EOF
+	$(grep -v patch.description <trailers)
+
+	EOF
+
+test_trailer_option '%(trailers:only=no) shows all trailers' \
+	'trailers:only=no' <<-EOF
+	$(cat trailers)
+
+	EOF
+
+test_trailer_option '%(trailers:only) and %(trailers:unfold) work together' \
+	'trailers:only,unfold' <<-EOF
+	$(grep -v patch.description <trailers | unfold)
+
+	EOF
+
+test_trailer_option '%(trailers:unfold) and %(trailers:only) work together' \
+	'trailers:unfold,only' <<-EOF
+	$(grep -v patch.description <trailers | unfold)
+
+	EOF
+
+test_trailer_option '%(trailers:key=foo) shows that trailer' \
+	'trailers:key=Signed-off-by' <<-EOF
+	Signed-off-by: A U Thor <author@example.com>
+
+	EOF
+
+test_trailer_option '%(trailers:key=foo) is case insensitive' \
+	'trailers:key=SiGned-oFf-bY' <<-EOF
+	Signed-off-by: A U Thor <author@example.com>
+
+	EOF
+
+test_trailer_option '%(trailers:key=foo:) trailing colon also works' \
+	'trailers:key=Signed-off-by:' <<-EOF
+	Signed-off-by: A U Thor <author@example.com>
+
+	EOF
+
+test_trailer_option '%(trailers:key=foo) multiple keys' \
+	'trailers:key=Reviewed-by:,key=Signed-off-by' <<-EOF
+	Reviewed-by: A U Thor <author@example.com>
+	Signed-off-by: A U Thor <author@example.com>
+
+	EOF
+
+test_trailer_option '%(trailers:key=nonexistent) becomes empty' \
+	'trailers:key=Shined-off-by:' <<-EOF
+
+	EOF
+
+test_trailer_option '%(trailers:key=foo) handles multiple lines even if folded' \
+	'trailers:key=Acked-by' <<-EOF
+	$(grep -v patch.description <trailers | grep -v Signed-off-by | grep -v Reviewed-by)
+
+	EOF
+
+test_trailer_option '%(trailers:key=foo,unfold) properly unfolds' \
+	'trailers:key=Signed-Off-by,unfold' <<-EOF
+	$(unfold <trailers | grep Signed-off-by)
+
+	EOF
+
+test_trailer_option '%(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)
+
+	EOF
+
+test_trailer_option '%(trailers:key=foo,valueonly) shows only value' \
+	'trailers:key=Signed-off-by,valueonly' <<-EOF
+	A U Thor <author@example.com>
+
+	EOF
+
+test_trailer_option '%(trailers:separator) changes separator' \
+	'trailers:separator=%x2C,key=Reviewed-by,key=Signed-off-by:' <<-EOF
+	Reviewed-by: A U Thor <author@example.com>,Signed-off-by: A U Thor <author@example.com>
+	EOF
+
+test_trailer_option '%(trailers:key_value_separator) changes key-value separator' \
+	'trailers:key_value_separator=%x2C,key=Reviewed-by,key=Signed-off-by:' <<-EOF
+	Reviewed-by,A U Thor <author@example.com>
+	Signed-off-by,A U Thor <author@example.com>
+
+	EOF
+
+test_trailer_option '%(trailers:separator,key_value_separator) changes both separators' \
+	'trailers:separator=%x2C,key_value_separator=%x2C,key=Reviewed-by,key=Signed-off-by:' <<-EOF
+	Reviewed-by,A U Thor <author@example.com>,Signed-off-by,A U Thor <author@example.com>
+	EOF
+
+test_failing_trailer_option () {
+	title=$1 option=$2
+	cat >expect
+	test_expect_success "$title" '
+		# error message cannot be checked under i18n
+		test_must_fail git for-each-ref --format="%($option)" refs/heads/main 2>actual &&
+		test_i18ncmp expect actual &&
+		test_must_fail git for-each-ref --format="%(contents:$option)" refs/heads/main 2>actual &&
+		test_i18ncmp expect actual
+	'
+}
+
+test_failing_trailer_option '%(trailers) rejects unknown trailers arguments' \
+	'trailers:unsupported' <<-\EOF
 	fatal: unknown %(trailers) argument: unsupported
 	EOF
-	test_must_fail git for-each-ref --format="%(trailers:unsupported)" 2>actual &&
-	test_i18ncmp expect actual &&
-	test_must_fail git for-each-ref --format="%(contents:trailers:unsupported)" 2>actual &&
-	test_i18ncmp expect actual
-'
+
+test_failing_trailer_option '%(trailers:key) without value is error' \
+	'trailers:key' <<-\EOF
+	fatal: expected %(trailers:key=<value>)
+	EOF
 
 test_expect_success 'if arguments, %(contents:trailers) shows error if colon is missing' '
 	cat >expect <<-EOF &&