Add more debugging for singleapplication handling

See #541

src/NotepadNext/NotepadNextApplication.cpp

@@ -195,20 +195,7 @@ bool NotepadNextApplication::init()
     });
 
     connect(this, &SingleApplication::instanceStarted, window, &MainWindow::bringWindowToForeground);
-
-    connect(this, &SingleApplication::receivedMessage, this, [&](quint32 instanceId, QByteArray message) {
-        Q_UNUSED(instanceId)
-
-        QDataStream stream(&message, QIODevice::ReadOnly);
-        QStringList args;
-
-        stream >> args;
-
-        QCommandLineParser parser;
-        parseCommandLine(parser, args);
-
-        openFiles(parser.positionalArguments());
-    }, Qt::QueuedConnection);
+    connect(this, &SingleApplication::receivedMessage, this, &NotepadNextApplication::receiveInfoFromSecondaryInstance, Qt::QueuedConnection);
 
     connect(this, &NotepadNextApplication::applicationStateChanged, this, [&](Qt::ApplicationState state) {
         if (state == Qt::ApplicationActive) {
@@ -420,11 +407,34 @@ QString NotepadNextApplication::detectLanguageFromContents(ScintillaNext *editor
 
 void NotepadNextApplication::sendInfoToPrimaryInstance()
 {
+    qInfo(Q_FUNC_INFO);
+
     QByteArray buffer;
     QDataStream stream(&buffer, QIODevice::WriteOnly);
 
     stream << arguments();
-    sendMessage(buffer);
+    const bool success = sendMessage(buffer);
+
+    if (!success) {
+        qWarning("sendMessage() unsuccessful");
+    }
+}
+
+void NotepadNextApplication::receiveInfoFromSecondaryInstance(quint32 instanceId, QByteArray message)
+{
+    qInfo(Q_FUNC_INFO);
+
+    Q_UNUSED(instanceId)
+
+    QDataStream stream(&message, QIODevice::ReadOnly);
+    QStringList args;
+
+    stream >> args;
+
+    QCommandLineParser parser;
+    parseCommandLine(parser, args);
+
+    openFiles(parser.positionalArguments());
 }
 
 bool NotepadNextApplication::isRunningAsAdmin() const

src/NotepadNext/NotepadNextApplication.h

@@ -72,6 +72,7 @@ class NotepadNextApplication : public SingleApplication
 
 private slots:
     void saveSettings();
+    void receiveInfoFromSecondaryInstance(quint32 instanceId, QByteArray message);
 
 private:
     void openFiles(const QStringList &files);