closingd: Tell closingd which chain we are working on

Signed-off-by: Christian Decker <decker.christian@gmail.com>

closingd/closing_wire.csv

@@ -3,6 +3,7 @@
 #include <common/per_peer_state.h>
 # Begin!  (passes peer fd, gossipd-client fd)
 msgtype,closing_init,2001
+msgdata,closing_init,chain_hash,chain_hash,
 msgdata,closing_init,pps,per_peer_state,
 msgdata,closing_init,funding_txid,bitcoin_txid,
 msgdata,closing_init,funding_txout,u16,

closingd/closingd.c

@@ -550,6 +550,7 @@ int main(int argc, char *argv[])
 	enum side whose_turn;
 	u8 *channel_reestablish;
 	struct secret last_remote_per_commit_secret;
+	struct bitcoin_blkid chain_hash;
 
 	subdaemon_setup(argc, argv);
 
@@ -557,6 +558,7 @@ int main(int argc, char *argv[])
 
 	msg = wire_sync_read(tmpctx, REQ_FD);
 	if (!fromwire_closing_init(ctx, msg,
+				   &chain_hash,
 				   &pps,
 				   &funding_txid, &funding_txout,
 				   &funding,

lightningd/closing_control.c

@@ -264,6 +264,7 @@ void peer_start_closingd(struct channel *channel,
 		return;
 	}
 	initmsg = towire_closing_init(tmpctx,
+				      &get_chainparams(ld)->genesis_blockhash,
 				      pps,
 				      &channel->funding_txid,
 				      channel->funding_outnum,