upload-pack: move filter_capability_requested to upload_pack_data

As we cleanup 'upload-pack.c' by using 'struct upload_pack_data'
more thoroughly, let's move the filter_capability_requested
static variable into this struct.

It is only used by protocol v0 code since protocol v2 assumes
certain baseline capabilities, but rolling it into
upload_pack_data and just letting v2 code ignore it as it does
now is more coherent and cleaner.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

upload-pack.c

@@ -57,7 +57,6 @@ static struct object_array extra_edge_obj;
 static int keepalive = 5;
 static const char *pack_objects_hook;
 
-static int filter_capability_requested;
 static int allow_filter;
 static int allow_ref_in_want;
 
@@ -93,6 +92,7 @@ struct upload_pack_data {
 	unsigned stateless_rpc : 1;				/* v0 only */
 	unsigned no_done : 1;					/* v0 only */
 	unsigned daemon_mode : 1;				/* v0 only */
+	unsigned filter_capability_requested : 1;		/* v0 only */
 
 	unsigned use_thin_pack : 1;
 	unsigned use_ofs_delta : 1;
@@ -943,7 +943,7 @@ static void receive_needs(struct upload_pack_data *data,
 			continue;
 
 		if (skip_prefix(reader->line, "filter ", &arg)) {
-			if (!filter_capability_requested)
+			if (!data->filter_capability_requested)
 				die("git upload-pack: filtering capability not negotiated");
 			list_objects_filter_die_if_populated(&data->filter_options);
 			parse_list_objects_filter(&data->filter_options, arg);
@@ -976,7 +976,7 @@ static void receive_needs(struct upload_pack_data *data,
 		if (parse_feature_request(features, "include-tag"))
 			data->use_include_tag = 1;
 		if (allow_filter && parse_feature_request(features, "filter"))
-			filter_capability_requested = 1;
+			data->filter_capability_requested = 1;
 
 		o = parse_object(the_repository, &oid_buf);
 		if (!o) {