add --must-filter, give error on filter not supported instead of warn

builtin/clone.c

@@ -887,6 +887,7 @@ int cmd_clone(int argc,
 	enum ref_storage_format ref_storage_format = REF_STORAGE_FORMAT_UNKNOWN;
 	const int do_not_override_repo_unix_permissions = -1;
 	int option_reject_shallow = -1; /* unspecified */
+	int must_filter = 0;
 	int deepen = 0;
 	char *option_template = NULL, *option_depth = NULL, *option_since = NULL;
 	char *option_origin = NULL;
@@ -915,6 +916,8 @@ int cmd_clone(int argc,
 			 N_("force progress reporting")),
 		OPT_BOOL(0, "reject-shallow", &option_reject_shallow,
 			 N_("don't clone shallow repository")),
+		OPT_BOOL(0, "must-filter", &must_filter,
+			 N_("error on filter not supported by server")),
 		OPT_BOOL('n', "no-checkout", &option_no_checkout,
 			 N_("don't create a checkout")),
 		OPT_BOOL(0, "bare", &option_bare, N_("create a bare repository")),
@@ -1333,6 +1336,9 @@ int cmd_clone(int argc,
 	transport_set_verbosity(transport, option_verbosity, option_progress);
 	transport->family = family;
 	transport->cloning = 1;
+	if (transport->smart_options) {
+		transport->smart_options->must_filter = must_filter;
+	}
 
 	if (is_bundle) {
 		struct bundle_header header = BUNDLE_HEADER_INIT;

builtin/fetch.c

@@ -84,7 +84,7 @@ static int prune_tags = -1; /* unspecified */
 
 static int append, dry_run, force, keep, update_head_ok;
 static int write_fetch_head = 1;
-static int verbosity, deepen_relative, set_upstream, refetch;
+static int verbosity, deepen_relative, set_upstream, refetch, must_filter;
 static int progress = -1;
 static int tags = TAGS_DEFAULT, update_shallow, deepen;
 static int atomic_fetch;
@@ -1508,6 +1508,9 @@ static struct transport *prepare_transport(struct remote *remote, int deepen)
 	transport = transport_get(remote, NULL);
 	transport_set_verbosity(transport, verbosity, progress);
 	transport->family = family;
+	if (transport->smart_options) {
+		transport->smart_options->must_filter = must_filter;
+	}
 	if (upload_pack)
 		set_option(transport, TRANS_OPT_UPLOADPACK, upload_pack);
 	if (keep)
@@ -2322,6 +2325,8 @@ int cmd_fetch(int argc,
 			 N_("append to .git/FETCH_HEAD instead of overwriting")),
 		OPT_BOOL(0, "atomic", &atomic_fetch,
 			 N_("use atomic transaction to update references")),
+		OPT_BOOL(0, "must-filter", &must_filter,
+			 N_("error on filter not supported by server")),
 		OPT_STRING(0, "upload-pack", &upload_pack, N_("path"),
 			   N_("path to upload pack on remote end")),
 		OPT__FORCE(&force, N_("force overwrite of local reference"), 0),

fetch-pack.c

@@ -319,9 +319,13 @@ static void send_filter(struct fetch_pack_args *args,
 			trace2_data_string("fetch", the_repository,
 					   "filter/effective", spec);
 		} else {
-			warning("filtering not recognized by server, ignoring");
-			trace2_data_string("fetch", the_repository,
+			if (args->must_filter) {
+				die("filtering not recognized by server");
+			} else {
+				warning("filtering not recognized by server, ignoring");
+				trace2_data_string("fetch", the_repository,
 					   "filter/unsupported", spec);
+			}
 		}
 	} else {
 		trace2_data_string("fetch", the_repository,

fetch-pack.h

@@ -40,6 +40,7 @@ struct fetch_pack_args {
 	unsigned cloning:1;
 	unsigned update_shallow:1;
 	unsigned reject_shallow_remote:1;
+	unsigned must_filter:1;
 	unsigned deepen:1;
 	unsigned refetch:1;
 

t/t0410-partial-clone.sh

@@ -48,6 +48,23 @@ test_expect_success 'convert shallow clone to partial clone' '
 	test_cmp_config -C client 1 core.repositoryformatversion
 '
 
+test_expect_failure 'must filter clone' '
+	rm -fr server client &&
+	test_create_repo server &&
+	test_commit -C server my_commit 1 &&
+	test_commit -C server my_commit2 1 &&
+	git clone --filter="blob:none" --must-filter "file://$(pwd)/server" client
+'
+
+test_expect_failure 'must filter fetch' '
+	rm -fr server client &&
+	test_create_repo server &&
+	test_commit -C server my_commit 1 &&
+	test_commit -C server my_commit2 1 &&
+	git clone --depth=1 "file://$(pwd)/server" client &&
+	git -C client fetch --unshallow --filter="blob:none" --must-filter
+'
+
 test_expect_success DEFAULT_REPO_FORMAT 'convert to partial clone with noop extension' '
 	rm -fr server client &&
 	test_create_repo server &&

transport.c

@@ -450,6 +450,7 @@ static int fetch_refs_via_pack(struct transport *transport,
 	args.quiet = (transport->verbose < 0);
 	args.no_progress = !transport->progress;
 	args.depth = data->options.depth;
+	args.must_filter = data->options.must_filter;
 	args.deepen_since = data->options.deepen_since;
 	args.deepen_not = data->options.deepen_not;
 	args.deepen_relative = data->options.deepen_relative;

transport.h

@@ -16,6 +16,7 @@ struct git_transport_options {
 	unsigned reject_shallow : 1;
 	unsigned deepen_relative : 1;
 	unsigned refetch : 1;
+	unsigned must_filter : 1;
 
 	/* see documentation of corresponding flag in fetch-pack.h */
 	unsigned from_promisor : 1;