Move write_shallow_commits to fetch-pack.c

This function produces network traffic and should be in fetch-pack. It
has been in commit.c because it needs to iterate (private) graft
list. It can now do so using for_each_commit_graft().

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/fetch-pack.c

@@ -185,6 +185,36 @@ static void consume_shallow_list(int fd)
 	}
 }
 
+struct write_shallow_data {
+	struct strbuf *out;
+	int use_pack_protocol;
+	int count;
+};
+
+static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
+{
+	struct write_shallow_data *data = cb_data;
+	const char *hex = sha1_to_hex(graft->sha1);
+	data->count++;
+	if (data->use_pack_protocol)
+		packet_buf_write(data->out, "shallow %s", hex);
+	else {
+		strbuf_addstr(data->out, hex);
+		strbuf_addch(data->out, '\n');
+	}
+	return 0;
+}
+
+static int write_shallow_commits(struct strbuf *out, int use_pack_protocol)
+{
+	struct write_shallow_data data;
+	data.out = out;
+	data.use_pack_protocol = use_pack_protocol;
+	data.count = 0;
+	for_each_commit_graft(write_one_shallow, &data);
+	return data.count;
+}
+
 static enum ack_type get_ack(int fd, unsigned char *result_sha1)
 {
 	static char line[1000];

commit.c

@@ -222,24 +222,6 @@ int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
 	return ret;
 }
 
-int write_shallow_commits(struct strbuf *out, int use_pack_protocol)
-{
-	int i, count = 0;
-	for (i = 0; i < commit_graft_nr; i++)
-		if (commit_graft[i]->nr_parent < 0) {
-			const char *hex =
-				sha1_to_hex(commit_graft[i]->sha1);
-			count++;
-			if (use_pack_protocol)
-				packet_buf_write(out, "shallow %s", hex);
-			else {
-				strbuf_addstr(out, hex);
-				strbuf_addch(out, '\n');
-			}
-		}
-	return count;
-}
-
 int unregister_shallow(const unsigned char *sha1)
 {
 	int pos = commit_graft_pos(sha1);

commit.h

@@ -154,7 +154,6 @@ extern struct commit_list *get_octopus_merge_bases(struct commit_list *in);
 
 extern int register_shallow(const unsigned char *sha1);
 extern int unregister_shallow(const unsigned char *sha1);
-extern int write_shallow_commits(struct strbuf *out, int use_pack_protocol);
 extern int for_each_commit_graft(each_commit_graft_fn, void *);
 extern int is_repository_shallow(void);
 extern struct commit_list *get_shallow_commits(struct object_array *heads,