qt, refactor: Allocate SendConfirmationDialog instances on heap

This change is require for the next commit.

Author: hebasto

src/qt/sendcoinsdialog.cpp

@@ -399,9 +399,10 @@ void SendCoinsDialog::sendButtonClicked([[maybe_unused]] bool checked)
 
     const QString confirmation = model->wallet().privateKeysDisabled() && !model->wallet().hasExternalSigner() ? tr("Confirm transaction proposal") : tr("Confirm send coins");
     const QString confirmButtonText = model->wallet().privateKeysDisabled() && !model->wallet().hasExternalSigner() ? tr("Create Unsigned") : tr("Sign and send");
-    SendConfirmationDialog confirmationDialog(confirmation, question_string, informative_text, detailed_text, SEND_CONFIRM_DELAY, confirmButtonText, this);
-    confirmationDialog.exec();
-    QMessageBox::StandardButton retval = static_cast<QMessageBox::StandardButton>(confirmationDialog.result());
+    auto confirmationDialog = new SendConfirmationDialog(confirmation, question_string, informative_text, detailed_text, SEND_CONFIRM_DELAY, confirmButtonText, this);
+    confirmationDialog->setAttribute(Qt::WA_DeleteOnClose);
+    // TODO: Replace QDialog::exec() with safer QDialog::show().
+    const auto retval = static_cast<QMessageBox::StandardButton>(confirmationDialog->exec());
 
     if(retval != QMessageBox::Yes)
     {

src/qt/walletmodel.cpp

@@ -506,9 +506,10 @@ bool WalletModel::bumpFee(uint256 hash, uint256& new_hash)
         questionString.append(tr("Warning: This may pay the additional fee by reducing change outputs or adding inputs, when necessary. It may add a new change output if one does not already exist. These changes may potentially leak privacy."));
     }
 
-    SendConfirmationDialog confirmationDialog(tr("Confirm fee bump"), questionString);
-    confirmationDialog.exec();
-    QMessageBox::StandardButton retval = static_cast<QMessageBox::StandardButton>(confirmationDialog.result());
+    auto confirmationDialog = new SendConfirmationDialog(tr("Confirm fee bump"), questionString);
+    confirmationDialog->setAttribute(Qt::WA_DeleteOnClose);
+    // TODO: Replace QDialog::exec() with safer QDialog::show().
+    const auto retval = static_cast<QMessageBox::StandardButton>(confirmationDialog->exec());
 
     // cancel sign&broadcast if user doesn't want to bump the fee
     if (retval != QMessageBox::Yes) {