CSerializeRecipientAddress: add Read method and make constructor private.

Co-authored-by: Kris Nuttycombe <kris@nutty.land>

src/wallet/walletdb.cpp

@@ -858,10 +858,9 @@ ReadKeyValue(CWallet* pwallet, CDataStream& ssKey, CDataStream& ssValue,
         else if (strType == "recipientmapping")
         {
             uint256 txid;
-            CSerializeRecipientAddress recipient;
             std::string rawUa;
             ssKey >> txid;
-            ssKey >> recipient;
+            auto recipient = CSerializeRecipientAddress::Read(ssKey);
             ssValue >> rawUa;
 
             auto ua = libzcash::UnifiedAddress::Parse(Params(), rawUa);
@@ -875,7 +874,7 @@ ReadKeyValue(CWallet* pwallet, CDataStream& ssKey, CDataStream& ssValue,
                 [&](const CKeyID& key) { recipientReceiver = key; },
                 [&](const CScriptID& scriptId) { recipientReceiver = scriptId; },
                 [&](const libzcash::SaplingPaymentAddress& addr) { recipientReceiver = addr; }
-            }, recipient.recipient);
+            }, recipient);
 
             bool found = false;
             for (const auto& receiver : ua.value().GetReceiversAsParsed()) {

src/wallet/walletdb.h

@@ -318,11 +318,11 @@ public:
 // as a pair of typecode and address bytes, similar to how unified address
 // receivers are written (but excluding the unknown receiver case)
 class CSerializeRecipientAddress {
+    libzcash::RecipientAddress recipient;
     libzcash::ReceiverType typecode;
+    CSerializeRecipientAddress() {} // for serialization only
 
     public:
-        libzcash::RecipientAddress recipient;
-        CSerializeRecipientAddress() {} // for serialization only
         CSerializeRecipientAddress(libzcash::RecipientAddress recipient): recipient(recipient) {}
 
         template<typename Stream>
@@ -369,6 +369,13 @@ class CSerializeRecipientAddress {
                 }
             }
         }
+
+        template <typename Stream>
+        static libzcash::RecipientAddress Read(Stream& stream) {
+            CSerializeRecipientAddress csr;
+            stream >> csr;
+            return csr.recipient;
+        }
 };
 
 /** Access to the wallet database */