[PATCH 1/5] trailer: separate public from internal portion of trailer_iterator

["Linus Arver via GitGitGadget" <gitgitgadget@xxxxxxxxx>]

From: Linus Arver <linusa@xxxxxxxxxx>

The fields here are not meant to be used by downstream callers, so put
them behind an anonymous struct named as
"__private_to_trailer_c__do_not_use" to warn against their use.

Internally, use a "#define" to keep the code tidy.

Helped-by: Junio C Hamano <gitster@xxxxxxxxx>
Signed-off-by: Linus Arver <linusa@xxxxxxxxxx>
---
 trailer.c | 12 +++++++-----
 trailer.h |  6 ++++--
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/trailer.c b/trailer.c
index f408f9b058d..dff3fafe865 100644
--- a/trailer.c
+++ b/trailer.c
@@ -1214,20 +1214,22 @@ void format_trailers_from_commit(struct strbuf *out, const char *msg,
 	trailer_info_release(&info);
 }
 
+#define private __private_to_trailer_c__do_not_use
+
 void trailer_iterator_init(struct trailer_iterator *iter, const char *msg)
 {
 	struct process_trailer_options opts = PROCESS_TRAILER_OPTIONS_INIT;
 	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->private.info, msg, &opts);
+	iter->private.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->private.cur < iter->private.info.trailer_nr) {
+		char *trailer = iter->private.info.trailers[iter->private.cur++];
 		int separator_pos = find_separator(trailer, separators);
 
 		if (separator_pos < 1)
@@ -1245,7 +1247,7 @@ 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->private.info);
 	strbuf_release(&iter->val);
 	strbuf_release(&iter->key);
 }
diff --git a/trailer.h b/trailer.h
index 795d2fccfd9..db57e028650 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;
+	} __private_to_trailer_c__do_not_use;
 };
 
 /*
-- 
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