tests: define GIT_TEST_SIDEBAND_ALL

Define a GIT_TEST_SIDEBAND_ALL environment variable meant to be used
from tests. When set to true, this overrides uploadpack.allowsidebandall
to true, allowing the entire test suite to be run as if this
configuration is in place for all repositories.

As of this patch, all tests pass whether GIT_TEST_SIDEBAND_ALL is unset
or set to 1.

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

fetch-pack.c

@@ -1327,7 +1327,8 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
 	packet_reader_init(&reader, fd[0], NULL, 0,
 			   PACKET_READ_CHOMP_NEWLINE |
 			   PACKET_READ_DIE_ON_ERR_PACKET);
-	if (server_supports_feature("fetch", "sideband-all", 0)) {
+	if (git_env_bool("GIT_TEST_SIDEBAND_ALL", 1) &&
+	    server_supports_feature("fetch", "sideband-all", 0)) {
 		reader.use_sideband = 1;
 		reader.me = "fetch-pack";
 	}

t/README

@@ -358,6 +358,11 @@ GIT_TEST_MULTI_PACK_INDEX=<boolean>, when true, forces the multi-pack-
 index to be written after every 'git repack' command, and overrides the
 'core.multiPackIndex' setting to true.
+GIT_TEST_SIDEBAND_ALL=<boolean>, when true, overrides the
+'uploadpack.allowSidebandAll' setting to true, and when false, forces
+fetch-pack to not request sideband-all (even if the server advertises
+sideband-all).
+
 Naming Tests
 ------------

t/lib-httpd/apache.conf

@@ -78,6 +78,7 @@ PassEnv GNUPGHOME
 PassEnv ASAN_OPTIONS
 PassEnv GIT_TRACE
 PassEnv GIT_CONFIG_NOSYSTEM
+PassEnv GIT_TEST_SIDEBAND_ALL
 SetEnvIf Git-Protocol ".*" GIT_PROTOCOL=$0

t/t5537-fetch-shallow.sh

@@ -243,7 +243,8 @@ test_expect_success 'shallow fetches check connectivity before writing shallow f
 	       "$(git -C "$REPO" rev-parse HEAD)" \
 	       "$(git -C "$REPO" rev-parse HEAD^)" \
 	       >"$HTTPD_ROOT_PATH/one-time-sed" &&
-	test_must_fail git -C client fetch --depth=1 "$HTTPD_URL/one_time_sed/repo" \
+	test_must_fail env GIT_TEST_SIDEBAND_ALL=0 git -C client \
+		fetch --depth=1 "$HTTPD_URL/one_time_sed/repo" \
 		master:a_branch &&
 	# Ensure that the one-time-sed script was used.

t/t5701-git-serve.sh

@@ -14,7 +14,7 @@ test_expect_success 'test capability advertisement' '
 	0000
 	EOF
-	git serve --advertise-capabilities >out &&
+	GIT_TEST_SIDEBAND_ALL=0 git serve --advertise-capabilities >out &&
 	test-tool pkt-line unpack <out >actual &&
 	test_cmp expect actual
 '

t/t5702-protocol-v2.sh

@@ -583,8 +583,8 @@ test_expect_success 'when server does not send "ready", expect FLUSH' '
 	test_must_fail env GIT_TRACE_PACKET="$(pwd)/log" git -C http_child \
 		-c protocol.version=2 \
 		fetch "$HTTPD_URL/one_time_sed/http_parent" 2> err &&
-	grep "fetch< acknowledgments" log &&
-	! grep "fetch< ready" log &&
+	grep "fetch< .*acknowledgments" log &&
+	! grep "fetch< .*ready" log &&
 	test_i18ngrep "expected no other sections to be sent after no .ready." err
 '

upload-pack.c

@@ -1288,7 +1288,9 @@ static void process_args(struct packet_reader *request,
 			continue;
 		}
-		if (allow_sideband_all && !strcmp(arg, "sideband-all")) {
+		if ((git_env_bool("GIT_TEST_SIDEBAND_ALL", 0) ||
+		     allow_sideband_all) &&
+		    !strcmp(arg, "sideband-all")) {
 			data->writer.use_sideband = 1;
 			continue;
 		}
@@ -1521,10 +1523,11 @@ int upload_pack_advertise(struct repository *r,
 		    allow_ref_in_want)
 			strbuf_addstr(value, " ref-in-want");
-		if (!repo_config_get_bool(the_repository,
-					 "uploadpack.allowsidebandall",
-					 &allow_sideband_all_value) &&
-		    allow_sideband_all_value)
+		if (git_env_bool("GIT_TEST_SIDEBAND_ALL", 0) ||
+		    (!repo_config_get_bool(the_repository,
+					   "uploadpack.allowsidebandall",
+					   &allow_sideband_all_value) &&
+		     allow_sideband_all_value))
 			strbuf_addstr(value, " sideband-all");
 	}