diff --git a/src/gui/kernel/qwidget.cpp b/src/gui/kernel/qwidget.cpp
index 20d1d30..7975f8c 100644
--- a/src/gui/kernel/qwidget.cpp
+++ b/src/gui/kernel/qwidget.cpp
@@ -122,6 +122,8 @@
 #include "qtabwidget.h" // Needed in inTabWidget()
 #endif // QT_KEYPAD_NAVIGATION
 
+#include "QtCore/qbitarray.h"
+
 // widget/widget data creation count
 //#define QWIDGET_EXTRA_DEBUG
 //#define ALIEN_DEBUG
@@ -5368,7 +5370,7 @@ void QWidgetPrivate::drawWidget(QPaintDevice *pdev, const QRegion &rgn, const QP
     }
 
     if (recursive && !children.isEmpty()) {
-        paintSiblingsRecursive(pdev, children, children.size() - 1, rgn, offset, flags & ~DrawAsRoot
+        paintSiblingsIterative(pdev, children, rgn, offset, flags & ~DrawAsRoot
 #ifdef Q_BACKINGSTORE_SUBSURFACES
                                 , q->windowSurface()
 #endif
@@ -5466,67 +5468,73 @@ void QWidgetPrivate::render(QPaintDevice *target, const QPoint &targetOffset,
 #endif
 }
 
-void QWidgetPrivate::paintSiblingsRecursive(QPaintDevice *pdev, const QObjectList& siblings, int index, const QRegion &rgn,
-                                            const QPoint &offset, int flags
+void QWidgetPrivate::paintSiblingsIterative(QPaintDevice *pdev, const QObjectList& siblings,
+    const QRegion &rgn, const QPoint &offset, int flags
 #ifdef Q_BACKINGSTORE_SUBSURFACES
-                                            , const QWindowSurface *currentSurface
+    , const QWindowSurface *currentSurface
 #endif
-                                            , QPainter *sharedPainter, QWidgetBackingStore *backingStore)
+    , QPainter *sharedPainter, QWidgetBackingStore *backingStore)
 {
-    QWidget *w = 0;
+    QBitArray skipArray;
     QRect boundingRect;
     bool dirtyBoundingRect = true;
     const bool exludeOpaqueChildren = (flags & DontDrawOpaqueChildren);
+    QRegion wr(rgn);
 
-    do {
-        QWidget *x =  qobject_cast<QWidget*>(siblings.at(index));
-        if (x && !(exludeOpaqueChildren && x->d_func()->isOpaque) && !x->isHidden() && !x->isWindow()) {
+    const int count = siblings.count();
+    skipArray.resize(count);
+
+    for (int index = count - 1; index >= 0; --index) {
+        QWidget *x = qobject_cast<QWidget*> (siblings.at(index));
+        bool skip = true;
+        if (x && !(exludeOpaqueChildren && x->d_func()->isOpaque) && !x->isHidden()
+            && !x->isWindow()) {
             if (dirtyBoundingRect) {
-                boundingRect = rgn.boundingRect();
+                boundingRect = wr.boundingRect();
                 dirtyBoundingRect = false;
             }
 
-            if (qRectIntersects(boundingRect, x->d_func()->effectiveRectFor(x->data->crect))) {
+            if (qRectIntersects(boundingRect, x->d_func()->effectiveRectFor(x->data->crect))
 #ifdef Q_BACKINGSTORE_SUBSURFACES
-                if (x->windowSurface() == currentSurface)
-#endif
-                {
-                    w = x;
-                    break;
+            && (x->windowSurface() == currentSurface)
+#endif
+            ) {
+                QWidgetPrivate *wd = x->d_func();
+                const QPoint widgetPos(x->data->crect.topLeft());
+                const bool hasMask = wd->extra && wd->extra->hasMask && !wd->graphicsEffect;
+                if (index > 0) {
+                    if (wd->isOpaque) {
+                        wr -= hasMask ? wd->extra->mask.translated(widgetPos) : x->data->crect;
+                        dirtyBoundingRect = true;
+                    }
+                }
+                if (x->updatesEnabled()
+#ifndef QT_NO_GRAPHICSVIEW
+                    && (!wd->extra || !wd->extra->proxyWidget)
+#endif //QT_NO_GRAPHICSVIEW
+                ) {
+                    skip = false;
                 }
             }
         }
-        --index;
-    } while (index >= 0);
-
-    if (!w)
-        return;
-
-    QWidgetPrivate *wd = w->d_func();
-    const QPoint widgetPos(w->data->crect.topLeft());
-    const bool hasMask = wd->extra && wd->extra->hasMask && !wd->graphicsEffect;
-    if (index > 0) {
-        QRegion wr(rgn);
-        if (wd->isOpaque)
-            wr -= hasMask ? wd->extra->mask.translated(widgetPos) : w->data->crect;
-        paintSiblingsRecursive(pdev, siblings, --index, wr, offset, flags
-#ifdef Q_BACKINGSTORE_SUBSURFACES
-                               , currentSurface
-#endif
-                               , sharedPainter, backingStore);
+        skipArray.setBit(index, skip);
     }
 
-    if (w->updatesEnabled()
-#ifndef QT_NO_GRAPHICSVIEW
-            && (!w->d_func()->extra || !w->d_func()->extra->proxyWidget)
-#endif //QT_NO_GRAPHICSVIEW
-       ) {
+    for (int index = 0; index < count; index++) {
+        if (skipArray.testBit(index))
+            continue;
         QRegion wRegion(rgn);
-        wRegion &= wd->effectiveRectFor(w->data->crect);
-        wRegion.translate(-widgetPos);
-        if (hasMask)
-            wRegion &= wd->extra->mask;
-        wd->drawWidget(pdev, wRegion, offset + widgetPos, flags, sharedPainter, backingStore);
+        QWidget* w = qobject_cast<QWidget*> (siblings.at(index));
+        if (w) {
+            QWidgetPrivate *wd = w->d_func();
+            const QPoint widgetPos(w->data->crect.topLeft());
+            wRegion &= wd->effectiveRectFor(w->data->crect);
+            wRegion.translate(-widgetPos);
+            const bool hasMask = wd->extra && wd->extra->hasMask && !wd->graphicsEffect;
+            if (hasMask)
+                wRegion &= wd->extra->mask;
+            wd->drawWidget(pdev, wRegion, offset + widgetPos, flags, sharedPainter, backingStore);
+        }
     }
 }
 
diff --git a/src/gui/kernel/qwidget_p.h b/src/gui/kernel/qwidget_p.h
index cad60b5..4d9a97e 100644
--- a/src/gui/kernel/qwidget_p.h
+++ b/src/gui/kernel/qwidget_p.h
@@ -392,7 +392,7 @@ public:
                     QPainter *sharedPainter = 0, QWidgetBackingStore *backingStore = 0);
 
 
-    void paintSiblingsRecursive(QPaintDevice *pdev, const QObjectList& children, int index,
+    void paintSiblingsIterative(QPaintDevice *pdev, const QObjectList& children,
                                 const QRegion &rgn, const QPoint &offset, int flags
 #ifdef Q_BACKINGSTORE_SUBSURFACES
                                 , const QWindowSurface *currentSurface