[PATCH 08/10] send-pack: support pack v4

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

Contrary to the fetch direction, whether send-pack sends packv4 is
totally controlled by the server. This is in favor of lowering load at
the server side. More logic may be added later to allow the client to
stick to v2 even if the server requests v4.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 send-pack.c           |  5 +++++
 send-pack.h           |  1 +
 t/t5516-fetch-push.sh | 12 ++++++++++++
 3 files changed, 18 insertions(+)

diff --git a/send-pack.c b/send-pack.c
index 7d172ef..977c14b 100644
--- a/send-pack.c
+++ b/send-pack.c
@@ -44,6 +44,7 @@ static int pack_objects(int fd, struct ref *refs, struct extra_have_objects *ext
 		NULL,
 		NULL,
 		NULL,
+		NULL,
 	};
 	struct child_process po;
 	int i;
@@ -57,6 +58,8 @@ static int pack_objects(int fd, struct ref *refs, struct extra_have_objects *ext
 		argv[i++] = "-q";
 	if (args->progress)
 		argv[i++] = "--progress";
+	if (args->packv4)
+		argv[i++] = "--version=4";
 	memset(&po, 0, sizeof(po));
 	po.argv = argv;
 	po.in = -1;
@@ -205,6 +208,8 @@ int send_pack(struct send_pack_args *args,
 		quiet_supported = 1;
 	if (server_supports("agent"))
 		agent_supported = 1;
+	if (server_supports("packv4"))
+		args->packv4 = 1;
 
 	if (!remote_refs) {
 		fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
diff --git a/send-pack.h b/send-pack.h
index 05d7ab1..cda770c 100644
--- a/send-pack.h
+++ b/send-pack.h
@@ -11,6 +11,7 @@ struct send_pack_args {
 		use_thin_pack:1,
 		use_ofs_delta:1,
 		dry_run:1,
+		packv4:1,
 		stateless_rpc:1;
 };
 
diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
index 4691d51..d0c116f 100755
--- a/t/t5516-fetch-push.sh
+++ b/t/t5516-fetch-push.sh
@@ -1172,4 +1172,16 @@ test_expect_success 'push --follow-tag only pushes relevant tags' '
 	test_cmp expect actual
 '
 
+test_expect_success 'push pack v4' '
+	git init pv4 &&
+	git --git-dir pv4/.git config core.preferredPackVersion 4 &&
+	git --git-dir pv4/.git config transfer.unpackLimit 1 &&
+	git push pv4 HEAD:refs/heads/head &&
+	P=`ls pv4/.git/objects/pack/pack-*.pack` &&
+	# Offset 4 is pack version
+	test-dump ntohl "$P" 4 >ver.actual &&
+	echo 4 >ver.expected &&
+	test_cmp ver.expected ver.actual
+'
+
 test_done
-- 
1.8.2.82.gc24b958