Fix invalid call on destroyed object

Part of !209

src/CompositeWidgetFocusWatcher.cpp

@@ -35,10 +35,14 @@ CompositeWidgetFocusWatcher::CompositeWidgetFocusWatcher(QWidget *compositeWidge
 
 bool CompositeWidgetFocusWatcher::eventFilter(QObject *watched, QEvent *event)
 {
-    Q_UNUSED(watched)
-
     auto *focusEvent = static_cast<QFocusEvent *>(event);
     switch(event->type()) {
+    case QEvent::Close:
+    case QEvent::DeferredDelete:
+    case QEvent::Destroy:
+        removeEventFilter(watched);
+        disconnect(this, &CompositeWidgetFocusWatcher::compositeFocusChanged, watched, nullptr);
+        break;
     case QEvent::FocusIn:
         emit compositeFocusChanged(true);
         break;

src/terminalDisplay/TerminalDisplay.cpp

@@ -577,7 +577,7 @@ TerminalDisplay::TerminalDisplay(QWidget* parent)
     new AutoScrollHandler(this);
 
     // Keep this last
-    auto focusWatcher = new CompositeWidgetFocusWatcher(this, this);
+    CompositeWidgetFocusWatcher *focusWatcher = new CompositeWidgetFocusWatcher(this, this);
     connect(focusWatcher, &CompositeWidgetFocusWatcher::compositeFocusChanged,
             this, [this](bool focused) {_hasCompositeFocus = focused;});
     connect(focusWatcher, &CompositeWidgetFocusWatcher::compositeFocusChanged,