Fixed "TQApplication::postEvent: Unexpected null receiver" warning message. This resolves bug 1901 and 1909.

diff --git a/src/kernel/qwidget.cpp b/src/kernel/qwidget.cpp
index 2b36de6..461c7f3 100644
--- a/src/kernel/qwidget.cpp
+++ b/src/kernel/qwidget.cpp
@@ -5984,9 +5984,9 @@
 
 void QWidget::updateGeometry()
 {
-    if ( !isTopLevel() && isShown() )
-	QApplication::postEvent( parentWidget(),
-				 new QEvent( QEvent::LayoutHint ) );
+  QWidget *parent = parentWidget();
+  if (parent && !isTopLevel() && isShown())
+	  QApplication::postEvent(parent, new QEvent(QEvent::LayoutHint));
 }