Return error when no ScriptPubKeyMan is available for specified type

When a CWallet doesn't have a ScriptPubKeyMan for the requested type
in GetNewDestination, give a meaningful error. Also handle this in
Qt which did not do anything with errors.

Author: achow101

src/qt/receivecoinsdialog.cpp

@@ -157,17 +157,40 @@ void ReceiveCoinsDialog::on_receiveButton_clicked()
         }
     }
     address = model->getAddressTableModel()->addRow(AddressTableModel::Receive, label, "", address_type);
-    SendCoinsRecipient info(address, label,
-        ui->reqAmount->value(), ui->reqMessage->text());
-    ReceiveRequestDialog *dialog = new ReceiveRequestDialog(this);
-    dialog->setAttribute(Qt::WA_DeleteOnClose);
-    dialog->setModel(model);
-    dialog->setInfo(info);
-    dialog->show();
-    clear();
 
-    /* Store request for later reference */
-    model->getRecentRequestsTableModel()->addNewRequest(info);
+    switch(model->getAddressTableModel()->getEditStatus())
+    {
+    case AddressTableModel::EditStatus::OK: {
+        // Success
+        SendCoinsRecipient info(address, label,
+            ui->reqAmount->value(), ui->reqMessage->text());
+        ReceiveRequestDialog *dialog = new ReceiveRequestDialog(this);
+        dialog->setAttribute(Qt::WA_DeleteOnClose);
+        dialog->setModel(model);
+        dialog->setInfo(info);
+        dialog->show();
+
+        /* Store request for later reference */
+        model->getRecentRequestsTableModel()->addNewRequest(info);
+        break;
+    }
+    case AddressTableModel::EditStatus::WALLET_UNLOCK_FAILURE:
+        QMessageBox::critical(this, windowTitle(),
+            tr("Could not unlock wallet."),
+            QMessageBox::Ok, QMessageBox::Ok);
+        break;
+    case AddressTableModel::EditStatus::KEY_GENERATION_FAILURE:
+        QMessageBox::critical(this, windowTitle(),
+            tr("Could not generate new %1 address").arg(QString::fromStdString(FormatOutputType(address_type))),
+            QMessageBox::Ok, QMessageBox::Ok);
+        break;
+    // These aren't valid return values for our action
+    case AddressTableModel::EditStatus::INVALID_ADDRESS:
+    case AddressTableModel::EditStatus::DUPLICATE_ADDRESS:
+    case AddressTableModel::EditStatus::NO_CHANGES:
+        assert(false);
+    }
+    clear();
 }
 
 void ReceiveCoinsDialog::on_recentRequestsView_doubleClicked(const QModelIndex &index)

src/wallet/wallet.cpp

@@ -3227,6 +3227,8 @@ bool CWallet::GetNewDestination(const OutputType type, const std::string label,
     if (spk_man) {
         spk_man->TopUp();
         result = spk_man->GetNewDestination(type, dest, error);
+    } else {
+        error = strprintf("Error: No %s addresses available.", FormatOutputType(type));
     }
     if (result) {
         SetAddressBook(dest, label, "receive");