splice: (todo del) fixes to go in other commits

channeld/channeld_wire.csv

@@ -191,6 +191,8 @@ msgtype,channeld_got_revoke_reply,1122
 
 # master->channeld: hello, I'd like to start a channel splice open
 msgtype,channeld_splice_init,7204
+msgdata,channeld_splice_init,psbt,wally_psbt,
+msgdata,channeld_splice_init,funding_amount,amount_sat,
 
 # channeld->master: hello, I started a channel splice open
 msgtype,channeld_splice_confirmed_init,7205

channeld/full_channel.c

@@ -299,6 +299,23 @@ struct bitcoin_tx **channel_txs(const tal_t *ctx,
 				const struct pubkey *per_commitment_point,
 				u64 commitment_number,
 				enum side side)
+{
+	return channel_splice_txs(ctx, &channel->funding, channel->funding_sats,
+				  htlcmap, direct_outputs, funding_wscript,
+				  channel, per_commitment_point,
+				  commitment_number, side);
+}
+
+struct bitcoin_tx **channel_splice_txs(const tal_t *ctx,
+				       const struct bitcoin_outpoint *funding,
+				       struct amount_sat funding_sats,
+				       const struct htlc ***htlcmap,
+				       struct wally_tx_output *direct_outputs[NUM_SIDES],
+				       const u8 **funding_wscript,
+				       const struct channel *channel,
+				       const struct pubkey *per_commitment_point,
+				       u64 commitment_number,
+				       enum side side)
 {
 	struct bitcoin_tx **txs;
 	const struct htlc **committed;
@@ -322,8 +339,8 @@ struct bitcoin_tx **channel_txs(const tal_t *ctx,
 
 	txs = tal_arr(ctx, struct bitcoin_tx *, 1);
 	txs[0] = commit_tx(
-	    ctx, &channel->funding,
-	    channel->funding_sats,
+	    ctx, funding,
+	    funding_sats,
 	    &channel->funding_pubkey[side],
 	    &channel->funding_pubkey[!side],
 	    channel->opener,

channeld/full_channel.h

@@ -76,6 +76,20 @@ struct bitcoin_tx **channel_txs(const tal_t *ctx,
 				u64 commitment_number,
 				enum side side);
 
+/* Version of `channel_txs` that lets you specify a custom funding outpoint
+ * and funding_sats.
+ */
+struct bitcoin_tx **channel_splice_txs(const tal_t *ctx,
+				       const struct bitcoin_outpoint *funding,
+				       struct amount_sat funding_sats,
+				       const struct htlc ***htlcmap,
+				       struct wally_tx_output *direct_outputs[NUM_SIDES],
+				       const u8 **funding_wscript,
+				       const struct channel *channel,
+				       const struct pubkey *per_commitment_point,
+				       u64 commitment_number,
+				       enum side side);
+
 /**
  * actual_feerate: what is the actual feerate for the local side.
  * @channel: The channel state

common/amount.c

@@ -37,6 +37,16 @@ struct amount_sat amount_msat_to_sat_round_down(struct amount_msat msat)
 	return sat;
 }
 
+struct amount_sat amount_msat_to_sat_round(struct amount_msat msat)
+{
+	struct amount_sat sat;
+
+	sat.satoshis = msat.millisatoshis / MSAT_PER_SAT;
+	if (msat.millisatoshis % MSAT_PER_SAT >= MSAT_PER_SAT / 2)
+		sat.satoshis++;
+	return sat;
+}
+
 /* Different formatting by amounts: btc, sat and msat */
 const char *fmt_amount_msat_btc(const tal_t *ctx,
 				struct amount_msat msat,

common/amount.h

@@ -60,6 +60,8 @@ WARN_UNUSED_RESULT bool amount_msat_to_sat(struct amount_sat *sat,
 /* You can always truncate millisatoshis->satoshis. */
 struct amount_sat amount_msat_to_sat_round_down(struct amount_msat msat);
 
+struct amount_sat amount_msat_to_sat_round(struct amount_msat msat);
+
 /* Simple operations: val = a + b, val = a - b. */
 WARN_UNUSED_RESULT bool amount_msat_add(struct amount_msat *val,
 					struct amount_msat a,