diff --git a/trailer.c b/trailer.c
index f408f9b058..b6de5d9cb2 100644
--- a/trailer.c
+++ b/trailer.c
@@ -711,10 +711,25 @@ static void add_arg_item(struct list_head *arg_head, char *tok, char *val,
 	list_add_tail(&new_item->list, arg_head);
 }
 
-static void process_command_line_args(struct list_head *arg_head,
-				      struct list_head *new_trailer_head)
+static void parse_trailers_from_config(struct list_head *config_head)
 {
 	struct arg_item *item;
+	struct list_head *pos;
+
+	/* Add an arg item for each configured trailer with a command */
+	list_for_each(pos, &conf_head) {
+		item = list_entry(pos, struct arg_item, list);
+		if (item->conf.command)
+			add_arg_item(config_head,
+				     xstrdup(token_from_item(item, NULL)),
+				     xstrdup(""),
+				     &item->conf, NULL);
+	}
+}
+
+static void parse_trailers_from_command_line_args(struct list_head *arg_head,
+						  struct list_head *new_trailer_head)
+{
 	struct strbuf tok = STRBUF_INIT;
 	struct strbuf val = STRBUF_INIT;
 	const struct conf_info *conf;
@@ -726,16 +741,6 @@ static void process_command_line_args(struct list_head *arg_head,
 	 */
 	char *cl_separators = xstrfmt("=%s", separators);
 
-	/* Add an arg item for each configured trailer with a command */
-	list_for_each(pos, &conf_head) {
-		item = list_entry(pos, struct arg_item, list);
-		if (item->conf.command)
-			add_arg_item(arg_head,
-				     xstrdup(token_from_item(item, NULL)),
-				     xstrdup(""),
-				     &item->conf, NULL);
-	}
-
 	/* Add an arg item for each trailer on the command line */
 	list_for_each(pos, new_trailer_head) {
 		struct new_trailer_item *tr =
@@ -961,28 +966,24 @@ static void unfold_value(struct strbuf *val)
 	strbuf_release(&out);
 }
 
-static size_t process_input_file(FILE *outfile,
-				 const char *str,
-				 struct list_head *head,
-				 const struct process_trailer_options *opts)
+/*
+ * Parse trailers in "str", populating the trailer info and "head"
+ * linked list structure.
+ */
+static void parse_trailers(struct trailer_info *info,
+			     const char *str,
+			     struct list_head *head,
+			     const struct process_trailer_options *opts)
 {
-	struct trailer_info info;
 	struct strbuf tok = STRBUF_INIT;
 	struct strbuf val = STRBUF_INIT;
 	size_t i;
 
-	trailer_info_get(&info, str, opts);
+	trailer_info_get(info, str, opts);
 
-	/* Print lines before the trailers as is */
-	if (!opts->only_trailers)
-		fwrite(str, 1, info.trailer_start - str, outfile);
-
-	if (!opts->only_trailers && !info.blank_line_before_trailer)
-		fprintf(outfile, "\n");
-
-	for (i = 0; i < info.trailer_nr; i++) {
+	for (i = 0; i < info->trailer_nr; i++) {
 		int separator_pos;
-		char *trailer = info.trailers[i];
+		char *trailer = info->trailers[i];
 		if (trailer[0] == comment_line_char)
 			continue;
 		separator_pos = find_separator(trailer, separators);
@@ -1002,10 +1003,6 @@ static size_t process_input_file(FILE *outfile,
 					 strbuf_detach(&val, NULL));
 		}
 	}
-
-	trailer_info_release(&info);
-
-	return info.trailer_end - str;
 }
 
 static void free_all(struct list_head *head)
@@ -1054,6 +1051,7 @@ void process_trailers(const char *file,
 {
 	LIST_HEAD(head);
 	struct strbuf sb = STRBUF_INIT;
+	struct trailer_info info;
 	size_t trailer_end;
 	FILE *outfile = stdout;
 
@@ -1064,18 +1062,30 @@ void process_trailers(const char *file,
 	if (opts->in_place)
 		outfile = create_in_place_tempfile(file);
 
+	parse_trailers(&info, sb.buf, &head, opts);
+	trailer_end = info.trailer_end - sb.buf;
+
 	/* Print the lines before the trailers */
-	trailer_end = process_input_file(outfile, sb.buf, &head, opts);
+	if (!opts->only_trailers)
+		fwrite(sb.buf, 1, info.trailer_start - sb.buf, outfile);
+
+	if (!opts->only_trailers && !info.blank_line_before_trailer)
+		fprintf(outfile, "\n");
+
 
 	if (!opts->only_input) {
+		LIST_HEAD(config_head);
 		LIST_HEAD(arg_head);
-		process_command_line_args(&arg_head, new_trailer_head);
+		parse_trailers_from_config(&config_head);
+		parse_trailers_from_command_line_args(&arg_head, new_trailer_head);
+		list_splice(&config_head, &arg_head);
 		process_trailers_lists(&head, &arg_head);
 	}
 
 	print_all(outfile, &head, opts);
 
 	free_all(&head);
+	trailer_info_release(&info);
 
 	/* Print the lines after the trailers as is */
 	if (!opts->only_trailers)
@@ -1220,14 +1230,14 @@ void trailer_iterator_init(struct trailer_iterator *iter, const char *msg)
 	strbuf_init(&iter->key, 0);
 	strbuf_init(&iter->val, 0);
 	opts.no_divider = 1;
-	trailer_info_get(&iter->info, msg, &opts);
-	iter->cur = 0;
+	trailer_info_get(&iter->internal.info, msg, &opts);
+	iter->internal.cur = 0;
 }
 
 int trailer_iterator_advance(struct trailer_iterator *iter)
 {
-	while (iter->cur < iter->info.trailer_nr) {
-		char *trailer = iter->info.trailers[iter->cur++];
+	while (iter->internal.cur < iter->internal.info.trailer_nr) {
+		char *trailer = iter->internal.info.trailers[iter->internal.cur++];
 		int separator_pos = find_separator(trailer, separators);
 
 		if (separator_pos < 1)
@@ -1245,7 +1255,7 @@ int trailer_iterator_advance(struct trailer_iterator *iter)
 
 void trailer_iterator_release(struct trailer_iterator *iter)
 {
-	trailer_info_release(&iter->info);
+	trailer_info_release(&iter->internal.info);
 	strbuf_release(&iter->val);
 	strbuf_release(&iter->key);
 }
diff --git a/trailer.h b/trailer.h
index 795d2fccfd..ab2cd01756 100644
--- a/trailer.h
+++ b/trailer.h
@@ -119,8 +119,10 @@ struct trailer_iterator {
 	struct strbuf val;
 
 	/* private */
-	struct trailer_info info;
-	size_t cur;
+	struct {
+		struct trailer_info info;
+		size_t cur;
+	} internal;
 };
 
 /*