Write leaf encoding field in encodeLeaf

lib/trie/hash.go

@@ -94,12 +94,6 @@ func encodeNode(n node, buffer *bytes.Buffer, parallel bool) (err error) {
 		if err != nil {
 			return fmt.Errorf("cannot encode leaf: %w", err)
 		}
-
-		n.encodingMu.Lock()
-		defer n.encodingMu.Unlock()
-
-		n.encoding = make([]byte, buffer.Len())
-		copy(n.encoding, buffer.Bytes())
 		return nil
 	case nil:
 		buffer.Write([]byte{0})
@@ -273,7 +267,7 @@ func encodeChild(child node, buffer io.Writer) (err error) {
 
 // encodeLeaf encodes a leaf to the buffer given, with the encoding
 // specified at the top of this package.
-func encodeLeaf(l *leaf, buffer io.Writer) (err error) {
+func encodeLeaf(l *leaf, buffer *bytes.Buffer) (err error) {
 	l.encodingMu.RLock()
 	defer l.encodingMu.RUnlock()
 	if !l.dirty && l.encoding != nil {
@@ -309,5 +303,11 @@ func encodeLeaf(l *leaf, buffer io.Writer) (err error) {
 		return fmt.Errorf("cannot write scale encoded value to buffer: %w", err)
 	}
 
+	l.encodingMu.Lock()
+	defer l.encodingMu.Unlock()
+
+	l.encoding = make([]byte, buffer.Len())
+	copy(l.encoding, buffer.Bytes())
+
 	return nil
 }