send-pack: support pushing to a shallow clone

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

builtin/send-pack.c

@@ -101,6 +101,7 @@ int cmd_send_pack(int argc, const char **argv, const char *prefix)
 	int fd[2];
 	struct child_process *conn;
 	struct sha1_array extra_have = SHA1_ARRAY_INIT;
+	struct sha1_array shallow = SHA1_ARRAY_INIT;
 	struct ref *remote_refs, *local_refs;
 	int ret;
 	int helper_status = 0;
@@ -232,7 +233,8 @@ int cmd_send_pack(int argc, const char **argv, const char *prefix)
 			args.verbose ? CONNECT_VERBOSE : 0);
 	}
 
-	get_remote_heads(fd[0], NULL, 0, &remote_refs, REF_NORMAL, &extra_have, NULL);
+	get_remote_heads(fd[0], NULL, 0, &remote_refs, REF_NORMAL,
+			 &extra_have, &shallow);
 
 	transport_verify_remote_names(nr_refspecs, refspecs);
 

t/t5538-push-shallow.sh

@@ -82,4 +82,42 @@ EOF
 	test_cmp expect actual
 '
 
+test_expect_success 'push from shallow to shallow' '
+	(
+	cd shallow &&
+	git --git-dir=../shallow2/.git config receive.shallowupdate true &&
+	git push ../shallow2/.git +master:refs/remotes/shallow/master &&
+	git --git-dir=../shallow2/.git config receive.shallowupdate false
+	) &&
+	(
+	cd shallow2 &&
+	git log --format=%s shallow/master >actual &&
+	git fsck &&
+	cat <<EOF >expect &&
+5
+4
+3
+EOF
+	test_cmp expect actual
+	)
+'
+
+test_expect_success 'push from full to shallow' '
+	! git --git-dir=shallow2/.git cat-file blob `echo 1|git hash-object --stdin` &&
+	commit 1 &&
+	git push shallow2/.git +master:refs/remotes/top/master &&
+	(
+	cd shallow2 &&
+	git log --format=%s top/master >actual &&
+	git fsck &&
+	cat <<EOF >expect &&
+1
+4
+3
+EOF
+	test_cmp expect actual &&
+	git cat-file blob `echo 1|git hash-object --stdin` >/dev/null
+	)
+'
+
 test_done

transport.c

@@ -819,11 +819,10 @@ static int git_transport_push(struct transport *transport, struct ref *remote_re
 		struct ref *tmp_refs;
 		connect_setup(transport, 1, 0);
 
-		get_remote_heads(data->fd[0], NULL, 0, &tmp_refs, REF_NORMAL, NULL, NULL);
+		get_remote_heads(data->fd[0], NULL, 0, &tmp_refs, REF_NORMAL,
+				 NULL, &data->shallow);
 		data->got_remote_heads = 1;
 	}
-	if (data->shallow.nr)
-		die("pushing to a shallow repository is not supported");
 
 	memset(&args, 0, sizeof(args));
 	args.send_mirror = !!(flags & TRANSPORT_PUSH_MIRROR);