stdin.patch

diff --git c/examples/widgets/windowcontainer/windowcontainer.cpp i/examples/widgets/windowcontainer/windowcontainer.cpp
index a104949d1eb..6bfc0e33bd2 100644
--- c/examples/widgets/windowcontainer/windowcontainer.cpp
+++ i/examples/widgets/windowcontainer/windowcontainer.cpp
@@ -162,6 +162,7 @@ int main(int argc, char *argv[])
     QHBoxLayout *layout = new QHBoxLayout(widget);
 
     Window *window = new Window;
+    window->setFlag(Qt::SubWindow);
 
     QWidget *container = QWidget::createWindowContainer(window);
     container->setMinimumSize(300, 300);
diff --git c/src/gui/kernel/qplatformintegration.cpp i/src/gui/kernel/qplatformintegration.cpp
index a53f0d09d71..1427db5c614 100644
--- c/src/gui/kernel/qplatformintegration.cpp
+++ i/src/gui/kernel/qplatformintegration.cpp
@@ -450,6 +450,9 @@ Qt::WindowState QPlatformIntegration::defaultWindowState(Qt::WindowFlags flags)
     if (flags & Qt::Popup & ~Qt::Window)
         return Qt::WindowNoState;
 
+     if (flags & Qt::SubWindow)
+        return Qt::WindowNoState;
+
     if (styleHint(QPlatformIntegration::ShowIsFullScreen).toBool())
         return Qt::WindowFullScreen;
     else if (styleHint(QPlatformIntegration::ShowIsMaximized).toBool())