tapgarden+tapscript: use P2TR dummy outputs

Author: jharveyb

tapgarden/caretaker.go

@@ -1,6 +1,7 @@
 package tapgarden
 
 import (
+	"bytes"
 	"context"
 	"errors"
 	"fmt"
@@ -30,8 +31,10 @@ import (
 var (
 	// GenesisDummyScript is a dummy script that we'll use to fund the
 	// initial PSBT packet that'll create initial set of assets. It's the
-	// same size as a encoded P2TR output.
-	GenesisDummyScript [34]byte
+	// same size as a encoded P2TR output and has a valid P2TR prefix.
+	GenesisDummyScript = append(
+		[]byte{0x51, 0x20}, bytes.Repeat([]byte{0x00}, 32)...,
+	)
 
 	// DummyGenesisTxOut is the dummy TxOut we'll place in the PSBt funding
 	// request to make sure we leave enough room for change and fees.

tapscript/send.go

@@ -1,6 +1,7 @@
 package tapscript
 
 import (
+	"bytes"
 	"context"
 	"encoding/hex"
 	"errors"
@@ -107,10 +108,13 @@ var (
 // createDummyOutput creates a new Bitcoin transaction output that is later
 // used to embed a Taproot Asset commitment.
 func createDummyOutput() *wire.TxOut {
-	// The dummy PkScript is the same size as an encoded P2TR output.
+	// The dummy PkScript is the same size as an encoded P2TR output and has
+	// a valid P2TR prefix.
 	newOutput := wire.TxOut{
-		Value:    int64(DummyAmtSats),
-		PkScript: make([]byte, 34),
+		Value: int64(DummyAmtSats),
+		PkScript: append(
+			[]byte{0x51, 0x20}, bytes.Repeat([]byte{0x00}, 32)...,
+		),
 	}
 	return &newOutput
 }