Get rid of PendingWalletTx class.

No reason for this class to exist if it doesn't have any code to run in the
destructor. e10e1e8db0 from
https://github.com/bitcoin/bitcoin/pull/16208 recently removed code destructor
code that would return an unused key if the transaction wasn't committed.

src/qt/sendcoinsdialog.cpp

@@ -392,7 +392,7 @@ void SendCoinsDialog::on_sendButton_clicked()
         accept();
         CoinControlDialog::coinControl()->UnSelectAll();
         coinControlUpdateLabels();
-        Q_EMIT coinsSent(currentTransaction.getWtx()->get().GetHash());
+        Q_EMIT coinsSent(currentTransaction.getWtx()->GetHash());
     }
     fNewRecipientAllowed = true;
 }

src/qt/walletmodel.cpp

@@ -261,11 +261,11 @@ WalletModel::SendCoinsReturn WalletModel::sendCoins(WalletModelTransaction &tran
 
         auto& newTx = transaction.getWtx();
         std::string rejectReason;
-        if (!newTx->commit({} /* mapValue */, std::move(vOrderForm), rejectReason))
+        if (!wallet().commitTransaction(newTx, {} /* mapValue */, std::move(vOrderForm), rejectReason))
             return SendCoinsReturn(TransactionCommitFailed, QString::fromStdString(rejectReason));
 
         CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
-        ssTx << newTx->get();
+        ssTx << *newTx;
         transaction_array.append(&(ssTx[0]), ssTx.size());
     }
 

src/qt/walletmodeltransaction.cpp

@@ -21,14 +21,14 @@ QList<SendCoinsRecipient> WalletModelTransaction::getRecipients() const
     return recipients;
 }
 
-std::unique_ptr<interfaces::PendingWalletTx>& WalletModelTransaction::getWtx()
+CTransactionRef& WalletModelTransaction::getWtx()
 {
     return wtx;
 }
 
 unsigned int WalletModelTransaction::getTransactionSize()
 {
-    return wtx ? GetVirtualTransactionSize(wtx->get()) : 0;
+    return wtx ? GetVirtualTransactionSize(*wtx) : 0;
 }
 
 CAmount WalletModelTransaction::getTransactionFee() const
@@ -43,7 +43,7 @@ void WalletModelTransaction::setTransactionFee(const CAmount& newFee)
 
 void WalletModelTransaction::reassignAmounts(int nChangePosRet)
 {
-    const CTransaction* walletTransaction = &wtx->get();
+    const CTransaction* walletTransaction = wtx.get();
     int i = 0;
     for (QList<SendCoinsRecipient>::iterator it = recipients.begin(); it != recipients.end(); ++it)
     {

src/qt/walletmodeltransaction.h

@@ -16,7 +16,6 @@ class SendCoinsRecipient;
 
 namespace interfaces {
 class Node;
-class PendingWalletTx;
 }
 
 /** Data model for a walletmodel transaction. */
@@ -27,7 +26,7 @@ public:
 
     QList<SendCoinsRecipient> getRecipients() const;
 
-    std::unique_ptr<interfaces::PendingWalletTx>& getWtx();
+    CTransactionRef& getWtx();
     unsigned int getTransactionSize();
 
     void setTransactionFee(const CAmount& newFee);
@@ -39,7 +38,7 @@ public:
 
 private:
     QList<SendCoinsRecipient> recipients;
-    std::unique_ptr<interfaces::PendingWalletTx> wtx;
+    CTransactionRef wtx;
     CAmount fee;
 };