1 files changed, 8 insertions, 1 deletions
diff --git a/src/plugins/platforms/windows/qwindowswindow.cpp b/src/plugins/platforms/windows/qwindowswindow.cpp
index 773d3f7102..8f376162ef 100644
--- a/src/plugins/platforms/windows/qwindowswindow.cpp
+++ b/src/plugins/platforms/windows/qwindowswindow.cpp
@@ -903,8 +903,15 @@ void QWindowsWindow::setParent_sys(const QPlatformWindow *parent) const
 
     }
 
+    // NULL handle means desktop window, which also has its proper handle -> disambiguate
+    HWND desktopHwnd = GetDesktopWindow();
+    if (oldParentHWND == desktopHwnd)
+        oldParentHWND = 0;
+    if (newParentHWND == desktopHwnd)
+        newParentHWND = 0;
+
     if (newParentHWND != oldParentHWND) {
-        const bool wasTopLevel = window()->isTopLevel();
+        const bool wasTopLevel = oldParentHWND == 0;
         const bool isTopLevel = newParentHWND == 0;
 
         setFlag(WithinSetParent);