Add null checks

src/mainwindow.cpp

@@ -39,7 +39,8 @@ MainWindow::MainWindow(QWidget *parent) :
 
     // Set up check for updates action
     QObject::connect(ui->actionCheck_for_Updates, &QAction::triggered, [=] () {
-        QDesktopServices::openUrl(QUrl("https://github.com/ZcashFoundation/zec-qt-wallet/releases"));
+        // Silent is false, so show notification even if no update was found
+        rpc->checkForUpdate(false);
     });
 
     // Pay zcash URI
@@ -659,21 +660,16 @@ void MainWindow::doImport(QList<QString>* keys) {
     }
 }
 
-void MainWindow::payZcashURIError(QString errorDetail) {
-    QMessageBox::critical(this, tr("Error paying zcash URI"), 
-            tr("URI should be of the form 'zcash:<addr>?amt=x&memo=y") + "\n" + errorDetail);
-}
-
 void MainWindow::payZcashURI() {
+    // Error to display if something goes wrong.
+    auto payZcashURIError = [=] (QString errorDetail = "") {
+        QMessageBox::critical(this, tr("Error paying zcash URI"), 
+                tr("URI should be of the form 'zcash:<addr>?amt=x&memo=y") + "\n" + errorDetail);
+    };
+
     // Read a zcash URI and pay it
-    QInputDialog uriDialog(this);
-    uriDialog.setInputMode(QInputDialog::TextInput);
-    uriDialog.setWindowTitle(tr("Paste zcash URI"));
-    uriDialog.setLabelText("zcash://" + QString(" ").repeated(180));    // Hack to adjust the width of the dialog
-    if (uriDialog.exec() != QDialog::Accepted) {
-        return;    
-    }
-    QString uri = uriDialog.textValue();
+    QString uri = QInputDialog::getText(this, tr("Paste zcash URI"),
+        "zcash://" + QString(" ").repeated(180));
 
     // URI should be of the form zcash://address?amt=x&memo=y
     if (!uri.startsWith("zcash:")) {
@@ -707,6 +703,11 @@ void MainWindow::payZcashURI() {
         QStringList args = uri.split("&");
         for (QString arg: args) {
             QStringList kv = arg.split("=");
+            if (kv.length() != 2) {
+                payZcashURIError();
+                return;
+            }
+
             if (kv[0].toLower() == "amt" || kv[0].toLower() == "amount") {
                 amount = kv[1].toDouble(); 
             } else if (kv[0].toLower() == "memo") {

src/mainwindow.h

@@ -89,7 +89,6 @@ private:
 
     void donate();
     void addressBook();
-    void payZcashURIError(QString errorDetail = "");
     void payZcashURI();
     void postToZBoard();
     void importPrivKey();

src/mainwindow.ui

@@ -1111,7 +1111,7 @@
   </action>
   <action name="actionPay_URI">
    <property name="text">
-    <string>Pay zcash URI...</string>
+    <string>Pay zcash &amp;URI...</string>
    </property>
   </action>
  </widget>

src/rpc.cpp

@@ -905,7 +905,7 @@ void RPC::watchTxStatus() {
     });
 }
 
-void RPC::checkForUpdate() {
+void RPC::checkForUpdate(bool silent) {
     if  (conn == nullptr) 
         return noConnection();
 
@@ -926,13 +926,18 @@ void RPC::checkForUpdate() {
                 QVersionNumber maxVersion(0, 0, 0);
 
                 for (QJsonValue rel : releases) {
+                    if (!rel.toObject().contains("tag_name"))
+                        continue;
+
                     QString tag = rel.toObject()["tag_name"].toString();
                     if (tag.startsWith("v"))
                         tag = tag.right(tag.length() - 1);
 
-                    auto v = QVersionNumber::fromString(tag);
-                    if (v > maxVersion)
-                        maxVersion = v;
+                    if (!tag.isEmpty()) {
+                        auto v = QVersionNumber::fromString(tag);
+                        if (v > maxVersion)
+                            maxVersion = v;
+                    }
                 }
 
                 auto currentVersion = QVersionNumber::fromString(APP_VERSION);
@@ -946,6 +951,12 @@ void RPC::checkForUpdate() {
                     if (ans == QMessageBox::Yes) {
                         QDesktopServices::openUrl(QUrl("https://github.com/ZcashFoundation/zec-qt-wallet/releases"));
                     }
+                } else {
+                    if (!silent) {
+                        QMessageBox::information(main, QObject::tr("No updates available"), 
+                            QObject::tr("You already have the latest release v%1")
+                                .arg(currentVersion.toString()));
+                    }
                 }
             }
         }

src/rpc.h

@@ -38,7 +38,7 @@ public:
 
     void refreshAddresses();    
     
-    void checkForUpdate();
+    void checkForUpdate(bool silent = true);
     void refreshZECPrice();
     void getZboardTopics(std::function<void(QMap<QString, QString>)> cb);