crash:dont show settings dialog in early startup

--showing settings dialog too early before layout(s)
are loaded can possible create crashes. Settings dialog
is considering that everything is in place and ready
to be used.

BUG:440731

app/lattecorona.cpp

@@ -267,6 +267,8 @@ void Corona::load()
             addOutput(screen);
         }
 
+        m_inStartup = false;
+
         connect(qGuiApp, &QGuiApplication::screenAdded, this, &Corona::addOutput, Qt::UniqueConnection);
         connect(qGuiApp, &QGuiApplication::screenRemoved, this, &Corona::screenRemoved, Qt::UniqueConnection);
     }
@@ -1117,6 +1119,10 @@ void Corona::switchToLayout(QString layout)
 
 void Corona::showSettingsWindow(int page)
 {
+    if (m_inStartup) {
+        return;
+    }
+
     Settings::Dialog::ConfigurationPage p = Settings::Dialog::LayoutPage;
 
     if (page >= Settings::Dialog::LayoutPage && page <= Settings::Dialog::PreferencesPage) {

app/lattecorona.h

@@ -211,6 +211,7 @@ private:
 
     bool m_activitiesStarting{true};
     bool m_defaultLayoutOnStartup{false}; //! this is used to enforce loading the default layout on startup
+    bool m_inStartup{true}; //! this is used in order to identify when application is still in startup phase
     bool m_inQuit{false}; //! this is used in order to identify when application is in quit phase
     bool m_quitTimedEnded{false}; //! this is used on destructor in order to delay it and slide-out the views
 

app/layouts/synchronizer.cpp

@@ -300,9 +300,14 @@ CentralLayout *Synchronizer::centralLayout(QString layoutname) const
 QList<CentralLayout *> Synchronizer::currentLayouts() const
 {
     QList<CentralLayout *> layouts;
+    layouts.clear();
+
+    if (m_centralLayouts.isEmpty()) {
+        return layouts;
+    }
 
     if (m_manager->memoryUsage() == MemoryUsage::SingleLayout) {
-        layouts << m_centralLayouts.at(0);
+        layouts << m_centralLayouts[0];
     } else {
         for (auto layout : m_centralLayouts) {
             if (layout->isOnAllActivities() || layout->appliedActivities().contains(m_manager->corona()->activitiesConsumer()->currentActivity())) {