interfaces: Stop exposing wallet destdata to gui

Stop giving GUI access to destdata rows in database. Replace with narrow
API just for saving and reading receive request information.

This simplifies code and should prevent the GUI from interfering with
other destdata like address-used status.

Note: No user-visible behavior is changing in this commit. New
CWallet::SetAddressReceiveRequest() implementation avoids a bug in
CWallet::AddDestData() where a modification would leave the previous
value in memory while writing the new value to disk. But it doesn't
matter because the GUI doesn't currently expose the ability to modify
receive requests, only to add and erase them.

src/qt/recentrequeststablemodel.cpp

@@ -10,7 +10,10 @@
 #include <qt/walletmodel.h>
 
 #include <clientversion.h>
+#include <interfaces/wallet.h>
+#include <key_io.h>
 #include <streams.h>
+#include <util/string.h>
 
 #include <utility>
 
@@ -18,10 +21,9 @@ RecentRequestsTableModel::RecentRequestsTableModel(WalletModel *parent) :
     QAbstractTableModel(parent), walletModel(parent)
 {
     // Load entries from wallet
-    std::vector<std::string> vReceiveRequests;
-    parent->loadReceiveRequests(vReceiveRequests);
-    for (const std::string& request : vReceiveRequests)
+    for (const std::string& request : parent->wallet().getAddressReceiveRequests()) {
         addNewRequest(request);
+    }
 
     /* These columns must match the indices in the ColumnIndex enumeration */
     columns << tr("Date") << tr("Label") << tr("Message") << getAmountTitle();
@@ -143,7 +145,7 @@ bool RecentRequestsTableModel::removeRows(int row, int count, const QModelIndex
         for (int i = 0; i < count; ++i)
         {
             const RecentRequestEntry* rec = &list[row+i];
-            if (!walletModel->saveReceiveRequest(rec->recipient.address.toStdString(), rec->id, ""))
+            if (!walletModel->wallet().setAddressReceiveRequest(DecodeDestination(rec->recipient.address.toStdString()), ToString(rec->id), ""))
                 return false;
         }
 
@@ -172,7 +174,7 @@ void RecentRequestsTableModel::addNewRequest(const SendCoinsRecipient &recipient
     CDataStream ss(SER_DISK, CLIENT_VERSION);
     ss << newEntry;
 
-    if (!walletModel->saveReceiveRequest(recipient.address.toStdString(), newEntry.id, ss.str()))
+    if (!walletModel->wallet().setAddressReceiveRequest(DecodeDestination(recipient.address.toStdString()), ToString(newEntry.id), ss.str()))
         return;
 
     addNewRequest(newEntry);

src/qt/test/wallettests.cpp

@@ -264,7 +264,7 @@ void TestGUI(interfaces::Node& node)
     QCOMPARE(currentRowCount, initialRowCount+1);
 
     // Check addition to wallet
-    std::vector<std::string> requests = walletModel.wallet().getDestValues("rr");
+    std::vector<std::string> requests = walletModel.wallet().getAddressReceiveRequests();
     QCOMPARE(requests.size(), size_t{1});
     RecentRequestEntry entry;
     CDataStream{MakeUCharSpan(requests[0]), SER_DISK, CLIENT_VERSION} >> entry;
@@ -286,7 +286,7 @@ void TestGUI(interfaces::Node& node)
     QCOMPARE(requestTableModel->rowCount({}), currentRowCount-1);
 
     // Check removal from wallet
-    QCOMPARE(walletModel.wallet().getDestValues("rr").size(), size_t{0});
+    QCOMPARE(walletModel.wallet().getAddressReceiveRequests().size(), size_t{0});
 }
 
 } // namespace

src/qt/walletmodel.cpp

@@ -463,25 +463,6 @@ void WalletModel::UnlockContext::CopyFrom(UnlockContext&& rhs)
     rhs.relock = false;
 }
 
-void WalletModel::loadReceiveRequests(std::vector<std::string>& vReceiveRequests)
-{
-    vReceiveRequests = m_wallet->getDestValues("rr"); // receive request
-}
-
-bool WalletModel::saveReceiveRequest(const std::string &sAddress, const int64_t nId, const std::string &sRequest)
-{
-    CTxDestination dest = DecodeDestination(sAddress);
-
-    std::stringstream ss;
-    ss << nId;
-    std::string key = "rr" + ss.str(); // "rr" prefix = "receive request" in destdata
-
-    if (sRequest.empty())
-        return m_wallet->eraseDestData(dest, key);
-    else
-        return m_wallet->addDestData(dest, key, sRequest);
-}
-
 bool WalletModel::bumpFee(uint256 hash, uint256& new_hash)
 {
     CCoinControl coin_control;

src/qt/walletmodel.h

@@ -135,9 +135,6 @@ public:
 
     UnlockContext requestUnlock();
 
-    void loadReceiveRequests(std::vector<std::string>& vReceiveRequests);
-    bool saveReceiveRequest(const std::string &sAddress, const int64_t nId, const std::string &sRequest);
-
     bool bumpFee(uint256 hash, uint256& new_hash);
 
     static bool isWalletEnabled();