1 files changed, 6 insertions, 1 deletions
diff --git a/src/widgets/kernel/qapplication.cpp b/src/widgets/kernel/qapplication.cpp
index ed6262ce93..c66a4487b4 100644
--- a/src/widgets/kernel/qapplication.cpp
+++ b/src/widgets/kernel/qapplication.cpp
@@ -2217,12 +2217,17 @@ Q_WIDGETS_EXPORT bool qt_tryModalHelper(QWidget *widget, QWidget **rettop)
 bool QApplicationPrivate::isBlockedByModal(QWidget *widget)
 {
     widget = widget->window();
-    return self->isWindowBlocked(widget->windowHandle());
+    QWindow *window = widget->windowHandle();
+    return window && self->isWindowBlocked(window);
 }
 
 bool QApplicationPrivate::isWindowBlocked(QWindow *window, QWindow **blockingWindow) const
 {
     QWindow *unused = 0;
+    if (!window) {
+        qWarning().nospace() << "window == 0 passed.";
+        return false;
+    }
     if (!blockingWindow)
         blockingWindow = &unused;