t5512: compensate for v0 only sending HEAD symrefs

Protocol v2 supports sending non-HEAD symrefs, but this is not true of
protocol v0. Some tests expect protocol v0 behavior, so fix them to use
protocol v0.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t5512-ls-remote.sh

@@ -223,7 +223,9 @@ test_expect_success 'ls-remote --symref' '
 	$(git rev-parse refs/tags/mark1.10)	refs/tags/mark1.10
 	$(git rev-parse refs/tags/mark1.2)	refs/tags/mark1.2
 	EOF
-	git ls-remote --symref >actual &&
+	# Protocol v2 supports sending symrefs for refs other than HEAD, so use
+	# protocol v0 here.
+	GIT_TEST_PROTOCOL_VERSION= git ls-remote --symref >actual &&
 	test_cmp expect actual
 '
 
@@ -232,7 +234,9 @@ test_expect_success 'ls-remote with filtered symref (refname)' '
 	ref: refs/heads/master	HEAD
 	1bd44cb9d13204b0fe1958db0082f5028a16eb3a	HEAD
 	EOF
-	git ls-remote --symref . HEAD >actual &&
+	# Protocol v2 supports sending symrefs for refs other than HEAD, so use
+	# protocol v0 here.
+	GIT_TEST_PROTOCOL_VERSION= git ls-remote --symref . HEAD >actual &&
 	test_cmp expect actual
 '
 
@@ -243,7 +247,9 @@ test_expect_failure 'ls-remote with filtered symref (--heads)' '
 	1bd44cb9d13204b0fe1958db0082f5028a16eb3a	refs/heads/foo
 	1bd44cb9d13204b0fe1958db0082f5028a16eb3a	refs/heads/master
 	EOF
-	git ls-remote --symref --heads . >actual &&
+	# Protocol v2 supports sending symrefs for refs other than HEAD, so use
+	# protocol v0 here.
+	GIT_TEST_PROTOCOL_VERSION= git ls-remote --symref --heads . >actual &&
 	test_cmp expect actual
 '
 
@@ -252,9 +258,11 @@ test_expect_success 'ls-remote --symref omits filtered-out matches' '
 	1bd44cb9d13204b0fe1958db0082f5028a16eb3a	refs/heads/foo
 	1bd44cb9d13204b0fe1958db0082f5028a16eb3a	refs/heads/master
 	EOF
-	git ls-remote --symref --heads . >actual &&
+	# Protocol v2 supports sending symrefs for refs other than HEAD, so use
+	# protocol v0 here.
+	GIT_TEST_PROTOCOL_VERSION= git ls-remote --symref --heads . >actual &&
 	test_cmp expect actual &&
-	git ls-remote --symref . "refs/heads/*" >actual &&
+	GIT_TEST_PROTOCOL_VERSION= git ls-remote --symref . "refs/heads/*" >actual &&
 	test_cmp expect actual
 '