Load previously persisted sent transaction recipient metadata back into the wallet.

This completes some unfinished work from #5549

src/wallet/wallet.cpp

@@ -853,6 +853,66 @@ bool CWallet::LoadUnifiedAddressMetadata(const ZcashdUnifiedAddressMetadata &add
                 addrmeta.GetReceiverTypes());
 }
 
+PaymentAddress CWallet::GetPaymentAddressForRecipient(const uint256& txid, const libzcash::RecipientAddress recipient) const {
+    // TODO: We should scrub change addresses from the results here.
+    auto defaultAddress = [&]() -> PaymentAddress {
+        return std::visit(match {
+            [&](const CKeyID& addr) {
+                auto ua = pwalletMain->FindUnifiedAddressByReceiver(addr);
+                if (ua.has_value()) {
+                    return libzcash::PaymentAddress{ua.value()};
+                } else {
+                    return libzcash::PaymentAddress{addr};
+                }
+            },
+            [&](const CScriptID& addr) {
+                auto ua = pwalletMain->FindUnifiedAddressByReceiver(addr);
+                if (ua.has_value()) {
+                    return libzcash::PaymentAddress{ua.value()};
+                } else {
+                    return libzcash::PaymentAddress{addr};
+                }
+            },
+            [&](const SaplingPaymentAddress& addr) {
+                auto ua = pwalletMain->FindUnifiedAddressByReceiver(addr);
+                if (ua.has_value()) {
+                    return libzcash::PaymentAddress{ua.value()};
+                } else {
+                    return libzcash::PaymentAddress{addr};
+                }
+            },
+            [&](const OrchardRawAddress& addr) {
+                auto ua = pwalletMain->FindUnifiedAddressByReceiver(addr);
+                if (ua.has_value()) {
+                    return libzcash::PaymentAddress{ua.value()};
+                } else {
+                    return libzcash::PaymentAddress{UnifiedAddress::ForSingleReceiver(addr)};
+                }
+            }
+        }, recipient);
+    };
+
+    auto recipientsPtr = sendRecipients.find(txid);
+    if (recipientsPtr == sendRecipients.end()) {
+        // we don't know the recipient, so we just return the simplest type
+        return defaultAddress();
+    } else {
+        // search the list of recipient mappings for one corresponding to
+        // our recipient, and return the known UA if it exists; otherwise
+        // just use the default.
+        for (const auto& mapping : recipientsPtr->second) {
+            if (mapping.address == recipient && mapping.ua.has_value()) {
+                return PaymentAddress{mapping.ua.value()};
+            }
+        }
+        return defaultAddress();
+    }
+}
+
+void CWallet::LoadRecipientMapping(const uint256& txid, const RecipientMapping& mapping) {
+    sendRecipients[txid].push_back(mapping);
+}
+
 bool CWallet::LoadCaches()
 {
     AssertLockHeld(cs_wallet);

src/wallet/wallet.h

@@ -1262,6 +1262,8 @@ public:
 
     std::map<uint256, CWalletTx> mapWallet;
 
+    std::map<uint256, std::vector<RecipientMapping>> sendRecipients;
+
     typedef std::multimap<int64_t, CWalletTx*> TxItems;
     TxItems wtxOrdered;
 
@@ -1578,6 +1580,9 @@ public:
     bool LoadUnifiedAccountMetadata(const ZcashdUnifiedAccountMetadata &skmeta);
     bool LoadUnifiedAddressMetadata(const ZcashdUnifiedAddressMetadata &addrmeta);
 
+    libzcash::PaymentAddress GetPaymentAddressForRecipient(const uint256& txid, const libzcash::RecipientAddress recipient) const;
+    void LoadRecipientMapping(const uint256& txid, const RecipientMapping& mapping);
+
     //! Reconstructs (in memory) caches and mappings for unified accounts,
     //! addresses and keying material. This should be called once, after the
     //! remainder of the on-disk wallet data has been loaded.
@@ -1665,12 +1670,13 @@ public:
 
         for (const auto& recipient : recipients)
         {
+            sendRecipients[txid].push_back(recipient);
             if (recipient.ua.has_value()) {
-                CWalletDB(strWalletFile).WriteRecipientMapping(
+                assert(CWalletDB(strWalletFile).WriteRecipientMapping(
                     txid,
                     recipient.address,
                     recipient.ua.value()
-                );
+                ));
             }
         }
 

src/wallet/walletdb.cpp

@@ -892,6 +892,8 @@ ReadKeyValue(CWallet* pwallet, CDataStream& ssKey, CDataStream& ssValue,
                 strErr = "Error in wallet database: recipientmapping UA does not contain recipient";
                 return false;
             }
+
+            pwallet->LoadRecipientMapping(txid, RecipientMapping(ua.value(), recipient));
         }
         else if (strType == "orchard_note_commitment_tree")
         {

src/zcash/Address.hpp

@@ -67,6 +67,12 @@ class UnifiedAddress {
 public:
     UnifiedAddress() {}
 
+    static UnifiedAddress ForSingleReceiver(Receiver receiver) {
+        UnifiedAddress ua;
+        ua.AddReceiver(receiver);
+        return ua;
+    }
+
     static std::optional<UnifiedAddress> Parse(const KeyConstants& keyConstants, const std::string& str);
 
     ADD_SERIALIZE_METHODS;