t5562: pass object-format in synthesized test data

Ensure that we pass the object-format capability in the synthesized test
data so that this test works with algorithms other than SHA-1.

In addition, add an additional test using the old data for when we're
using SHA-1 so that we can be sure that we preserve backwards
compatibility with servers not offering the object-format capability.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t5562-http-backend-content-length.sh

@@ -46,6 +46,7 @@ ssize_b100dots() {
 }
 
 test_expect_success 'setup' '
+	test_oid_init &&
 	HTTP_CONTENT_ENCODING="identity" &&
 	export HTTP_CONTENT_ENCODING &&
 	git config http.receivepack true &&
@@ -62,8 +63,8 @@ test_expect_success 'setup' '
 	test_copy_bytes 10 <fetch_body >fetch_body.trunc &&
 	hash_next=$(git commit-tree -p HEAD -m next HEAD^{tree}) &&
 	{
-		printf "%s %s refs/heads/newbranch\\0report-status\\n" \
-			"$ZERO_OID" "$hash_next" | packetize &&
+		printf "%s %s refs/heads/newbranch\\0report-status object-format=%s\\n" \
+			"$ZERO_OID" "$hash_next" "$(test_oid algo)" | packetize &&
 		printf 0000 &&
 		echo "$hash_next" | git pack-objects --stdout
 	} >push_body &&