Fix right click menu on migration screen

src/mainwindow.cpp

@@ -268,8 +268,10 @@ void MainWindow::turnstileProgress() {
 
 void MainWindow::turnstileDoMigration(QString fromAddr) {
     // Return if there is no connection
-    if (rpc->getAllZAddresses() == nullptr)
+    if (rpc->getAllZAddresses() == nullptr || rpc->getAllBalances() == nullptr) {
+        QMessageBox::information(this, tr("Not yet ready"), tr("zcashd is not yet ready. Please wait for the UI to load"), QMessageBox::Ok);
         return;
+    }
 
     // If a migration is already in progress, show the progress dialog instead
     if (rpc->getTurnstile()->isMigrationPresent()) {
@@ -288,7 +290,7 @@ void MainWindow::turnstileDoMigration(QString fromAddr) {
     auto fnGetAllSproutBalance = [=] () {
         double bal = 0;
         for (auto addr : *rpc->getAllZAddresses()) {
-            if (Settings::getInstance()->isSproutAddress(addr)) {
+            if (Settings::getInstance()->isSproutAddress(addr) && rpc->getAllBalances()) {
                 bal += rpc->getAllBalances()->value(addr);
             }
         }

src/turnstile.cpp

@@ -402,6 +402,10 @@ void Turnstile::showZcashdMigration(MainWindow* parent) {
         QMenu menu(parent);
         QString txid = model.getTxid(index.row());
 
+        menu.addAction("Copy txid", [=]() {
+            QGuiApplication::clipboard()->setText(txid);
+        });
+
         menu.addAction(QObject::tr("View on block explorer"), [=] () {
             QString url;
             if (Settings::getInstance()->isTestnet()) {
@@ -411,6 +415,8 @@ void Turnstile::showZcashdMigration(MainWindow* parent) {
             }
             QDesktopServices::openUrl(QUrl(url));
         });
+
+        menu.exec(md.tblTxids->viewport()->mapToGlobal(pos));
     });
 
     auto* status = parent->getRPC()->getMigrationStatus();