psbt: Make sighash_type std::optional<int>

It is better to ues an optional to determine whether the sighash type
is set rather than using 0 as a magic number.

1 files changed, 6 insertions, 4 deletions

diff --git a/src/psbt.h b/src/psbt.h
index 1171ecf1dd..21daa050ea 100644
--- a/src/psbt.h
+++ b/src/psbt.h
@@ -57,7 +57,7 @@ struct PSBTInput
     std::map<CPubKey, KeyOriginInfo> hd_keypaths;
     std::map<CKeyID, SigPair> partial_sigs;
     std::map<std::vector<unsigned char>, std::vector<unsigned char>> unknown;
-    int sighash_type = 0;
+    std::optional<int> sighash_type;
 
     bool IsNull() const;
     void FillSignatureData(SignatureData& sigdata) const;
@@ -86,9 +86,9 @@ struct PSBTInput
             }
 
             // Write the sighash type
-            if (sighash_type > 0) {
+            if (sighash_type != std::nullopt) {
                 SerializeToVector(s, PSBT_IN_SIGHASH);
-                SerializeToVector(s, sighash_type);
+                SerializeToVector(s, *sighash_type);
             }
 
             // Write the redeem script
@@ -201,7 +201,9 @@ struct PSBTInput
                     } else if (key.size() != 1) {
                         throw std::ios_base::failure("Sighash type key is more than one byte type");
                     }
-                    UnserializeFromVector(s, sighash_type);
+                    int sighash;
+                    UnserializeFromVector(s, sighash);
+                    sighash_type = sighash;
                     break;
                 case PSBT_IN_REDEEMSCRIPT:
                 {