stdin.patch

diff --git i/src/plugins/platforms/cocoa/qcocoabackingstore.mm w/src/plugins/platforms/cocoa/qcocoabackingstore.mm
index af50aabe15..f9e2f792eb 100644
--- i/src/plugins/platforms/cocoa/qcocoabackingstore.mm
+++ w/src/plugins/platforms/cocoa/qcocoabackingstore.mm
@@ -46,6 +46,13 @@
 
 #include <QuartzCore/CATransaction.h>
 
+#if !defined(QT_APPLE_NO_PRIVATE_APIS)
+extern "C" {
+CGContextRef CGIOSurfaceContextCreate(IOSurfaceRef, size_t, size_t, size_t, size_t, CGColorSpaceRef, CGBitmapInfo);
+CGImageRef CGIOSurfaceContextCreateImage(CGContextRef);
+}
+#endif
+
 QT_BEGIN_NAMESPACE
 
 QCocoaBackingStore::QCocoaBackingStore(QWindow *window)
@@ -531,6 +538,26 @@ void QCALayerBackingStore::flush(QWindow *flushedWindow, const QRegion &region,
     qCInfo(lcQpaBackingStore) << "Flushing" << backBufferSurface
          << "to" << flushedView.layer << "of" << flushedView;
 
+#if !defined(QT_APPLE_NO_PRIVATE_APIS)
+    CGBitmapInfo bitmapInfo = kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Host;
+    size_t bitsPerComponent = 8;
+    size_t bitsPerPixel = 32;
+    QSize bufferSize = m_buffers.back()->size();
+    QCFType<CGContextRef> context = CGIOSurfaceContextCreate(m_buffers.back()->surface(),
+        bufferSize.width(), bufferSize.height(), bitsPerComponent, bitsPerPixel,
+        colorSpace(), bitmapInfo);
+
+    QCFType<CGImageRef> image = CGIOSurfaceContextCreateImage(context);
+
+    if (flushedView != backingStoreView) {
+        auto rect = [flushedView convertRect:flushedView.bounds toView:backingStoreView];
+        auto scale = flushedView.layer.contentsScale;
+        rect = CGRectApplyAffineTransform(rect, CGAffineTransformMakeScale(scale, scale));
+        image = CGImageCreateWithImageInRect(image, rect);
+    }
+
+    flushedView.layer.contents = (__bridge id)static_cast<CGImageRef>(image);
+#else
     flushedView.layer.contents = backBufferSurface;
 
     if (flushedView != backingStoreView) {
@@ -540,6 +567,7 @@ void QCALayerBackingStore::flush(QWindow *flushedWindow, const QRegion &region,
             // The contentsRect is in unit coordinate system
             CGAffineTransformMakeScale(1.0 / backingStoreSize.width, 1.0 / backingStoreSize.height));
     }
+#endif
 
     // Since we may receive multiple flushes before a new frame is started, we do not
     // swap any buffers just yet. Instead we check in the next beginPaint if the layer's
diff --git i/src/widgets/kernel/qwidget.cpp w/src/widgets/kernel/qwidget.cpp
index 574a490ec7..0682bca3c3 100644
--- i/src/widgets/kernel/qwidget.cpp
+++ w/src/widgets/kernel/qwidget.cpp
@@ -5433,9 +5433,7 @@ void QWidgetPrivate::drawWidget(QPaintDevice *pdev, const QRegion &rgn, const QP
             }
             sourced->context = 0;
 
-            // Native widgets need to be marked dirty on screen so painting will be done in correct context
-            // Same check as in the no effects case below.
-            if (backingStore && !onScreen && !asRoot && (q->internalWinId() || !q->nativeParentWidget()->isWindow()))
+            if (backingStore)
                 backingStore->markDirtyOnScreen(rgn, q, offset);
 
             return;
@@ -5554,8 +5552,7 @@ void QWidgetPrivate::drawWidget(QPaintDevice *pdev, const QRegion &rgn, const QP
                 sendPaintEvent(toBePainted);
             }
 
-            // Native widgets need to be marked dirty on screen so painting will be done in correct context
-            if (backingStore && !onScreen && !asRoot && (q->internalWinId() || (q->nativeParentWidget() && !q->nativeParentWidget()->isWindow())))
+            if (backingStore)
                 backingStore->markDirtyOnScreen(toBePainted, q, offset);
 
             //restore
diff --git i/src/widgets/kernel/qwidgetbackingstore.cpp w/src/widgets/kernel/qwidgetbackingstore.cpp
index 48fc73a867..00d963811e 100644
--- i/src/widgets/kernel/qwidgetbackingstore.cpp
+++ w/src/widgets/kernel/qwidgetbackingstore.cpp
@@ -333,9 +333,6 @@ void QWidgetBackingStore::beginPaint(QRegion &toClean, QWidget *widget, QBacking
     Q_UNUSED(widget);
     Q_UNUSED(toCleanIsInTopLevelCoordinates);
 
-    // Always flush repainted areas.
-    dirtyOnScreen += toClean;
-
 #ifdef QT_NO_PAINT_DEBUG
     backingStore->beginPaint(toClean);
 #else
@@ -714,8 +711,7 @@ void QWidgetBackingStore::markDirtyOnScreen(const QRegion &region, QWidget *widg
 
     // Top-level.
     if (widget == tlw) {
-        if (!widget->testAttribute(Qt::WA_WState_InPaintEvent))
-            dirtyOnScreen += region;
+        dirtyOnScreen += region;
         return;
     }
 
@@ -723,8 +719,7 @@ void QWidgetBackingStore::markDirtyOnScreen(const QRegion &region, QWidget *widg
     if (!hasPlatformWindow(widget) && !widget->isWindow()) {
         QWidget *nativeParent = widget->nativeParentWidget();        // Alien widgets with the top-level as the native parent (common case).
         if (nativeParent == tlw) {
-            if (!widget->testAttribute(Qt::WA_WState_InPaintEvent))
-                dirtyOnScreen += region.translated(topLevelOffset);
+            dirtyOnScreen += region.translated(topLevelOffset);
             return;
         }
 
@@ -1175,11 +1170,6 @@ void QWidgetBackingStore::sync(QWidget *exposedWidget, const QRegion &exposedReg
         return;
     }
 
-    if (exposedWidget != tlw)
-        markDirtyOnScreen(exposedRegion, exposedWidget, exposedWidget->mapTo(tlw, QPoint()));
-    else
-        markDirtyOnScreen(exposedRegion, exposedWidget, QPoint());
-
     if (syncAllowed())
         doSync();
 }