lightningd: save short_channel_id in inflight struct as soon as it gets mined.

diff --git a/lightningd/channel.c b/lightningd/channel.c
index db05cf57..b15fdb2c 100644
--- a/lightningd/channel.c
+++ b/lightningd/channel.c
@@ -204,6 +204,7 @@ new_inflight(struct channel *channel,
 	inflight->funding_psbt = tal_steal(inflight, psbt);
 	inflight->last_tx = NULL;
 	inflight->tx_broadcast = false;
+	inflight->scid = NULL;
 
 	/* Channel lease infos */
 	inflight->lease_blockheight_start = lease_blockheight_start;
diff --git a/lightningd/channel.h b/lightningd/channel.h
index 9661e4b7..b96666e0 100644
--- a/lightningd/channel.h
+++ b/lightningd/channel.h
@@ -53,6 +53,9 @@ struct channel_inflight {
 	/* Channel context */
 	struct channel *channel;
 
+	/* SCID once we're mined, otherwise NULL */
+	struct short_channel_id *scid;
+
 	/* Funding info */
 	const struct funding_info *funding;
 	struct wally_psbt *funding_psbt;
diff --git a/lightningd/channel_control.c b/lightningd/channel_control.c
index 0da795ee..9735e72a 100644
--- a/lightningd/channel_control.c
+++ b/lightningd/channel_control.c
@@ -700,18 +700,11 @@ static enum watch_result splice_depth_cb(struct lightningd *ld,
 	}
 
 	if (inflight->channel->owner) {
-		/* FIXME: Save this in inflight so we don't neeed to re-derive. */
-		struct short_channel_id scid;
-		struct txlocator *loc = wallet_transaction_locate(tmpctx, ld->wallet, &inflight->funding->outpoint.txid);
-		if (!mk_short_channel_id(&scid,
-					 loc->blkheight, loc->index,
-					 inflight->funding->outpoint.n))
-			abort();
 		log_debug(inflight->channel->log, "splice_depth_cb: sending funding depth scid: %s",
-			  fmt_short_channel_id(tmpctx, scid));
+			  fmt_short_channel_id(tmpctx, *inflight->scid));
 		subd_send_msg(inflight->channel->owner,
 			      take(towire_channeld_funding_depth(
-					   NULL, &scid,
+					   NULL, inflight->scid,
 					   depth, true,
 					   &inflight->funding->outpoint.txid)));
 	}
@@ -726,6 +719,7 @@ static enum watch_result splice_reorged_cb(struct lightningd *ld, struct channel
 {
 	log_unusual(inflight->channel->log, "Splice inflight txid %s reorged out",
 		    fmt_bitcoin_txid(tmpctx, &inflight->funding->outpoint.txid));
+	inflight->scid = tal_free(inflight->scid);
 	return DELETE_WATCH;
 }
 
@@ -736,11 +730,13 @@ static void splice_found(struct lightningd *ld,
 			 const struct txlocator *loc,
 			 struct channel_inflight *inflight)
 {
-	struct short_channel_id scid;
+	assert(!inflight->scid);
+	inflight->scid = tal(inflight, struct short_channel_id);
 
-	if (!mk_short_channel_id(&scid,
+	if (!mk_short_channel_id(inflight->scid,
 				 loc->blkheight, loc->index,
 				 inflight->funding->outpoint.n)) {
+		inflight->scid = tal_free(inflight->scid);
 		channel_fail_permanent(inflight->channel,
 				       REASON_LOCAL,
 				       "Invalid funding scid %u:%u:%u",
diff --git a/lightningd/channel_control.h b/lightningd/channel_control.h
index 8eb1e118..b5d78381 100644
--- a/lightningd/channel_control.h
+++ b/lightningd/channel_control.h
@@ -9,6 +9,7 @@ struct crypto_state;
 struct lightningd;
 struct peer_fd;
 struct peer;
+struct txlocator;
 
 bool peer_start_channeld(struct channel *channel,
 			 struct peer_fd *peer_fd,
diff --git a/wallet/wallet.c b/wallet/wallet.c
index 47bf6e0f..2b080247 100644
--- a/wallet/wallet.c
+++ b/wallet/wallet.c
@@ -5263,34 +5263,6 @@ u32 wallet_transaction_height(struct wallet *w, const struct bitcoin_txid *txid)
 	return blockheight;
 }
 
-struct txlocator *wallet_transaction_locate(const tal_t *ctx, struct wallet *w,
-					    const struct bitcoin_txid *txid)
-{
-	struct txlocator *loc;
-	struct db_stmt *stmt;
-
-	stmt = db_prepare_v2(
-		w->db, SQL("SELECT blockheight, txindex FROM transactions WHERE id=?"));
-	db_bind_txid(stmt, txid);
-	db_query_prepared(stmt);
-
-	if (!db_step(stmt)) {
-		tal_free(stmt);
-		return NULL;
-	}
-
-	if (db_col_is_null(stmt, "blockheight")) {
-		db_col_ignore(stmt, "txindex");
-		loc = NULL;
-	} else {
-		loc = tal(ctx, struct txlocator);
-		loc->blkheight = db_col_int(stmt, "blockheight");
-		loc->index = db_col_int(stmt, "txindex");
-	}
-	tal_free(stmt);
-	return loc;
-}
-
 struct bitcoin_txid *wallet_transactions_by_height(const tal_t *ctx,
 						   struct wallet *w,
 						   const u32 blockheight)
diff --git a/wallet/wallet.h b/wallet/wallet.h
index d7a13132..589b4888 100644
--- a/wallet/wallet.h
+++ b/wallet/wallet.h
@@ -1280,13 +1280,6 @@ struct bitcoin_tx *wallet_transaction_get(const tal_t *ctx, struct wallet *w,
  */
 u32 wallet_transaction_height(struct wallet *w, const struct bitcoin_txid *txid);
 
-/**
- * Locate a transaction in the blockchain, returns NULL if the transaction is
- * not tracked or is not yet confirmed.
- */
-struct txlocator *wallet_transaction_locate(const tal_t *ctx, struct wallet *w,
-					    const struct bitcoin_txid *txid);
-
 /**
  * Get transaction IDs for transactions that we are tracking.
  */