5 files changed, 13 insertions, 5 deletions
diff --git a/src/gui/kernel/qapplication_mac.mm b/src/gui/kernel/qapplication_mac.mm
index eb0fd8d..0b9cad8 100644
--- a/src/gui/kernel/qapplication_mac.mm
+++ b/src/gui/kernel/qapplication_mac.mm
@@ -715,6 +715,7 @@ void qt_event_request_showsheet(QWidget *w)
 {
     Q_ASSERT(qt_mac_is_macsheet(w));
 #ifdef QT_MAC_USE_COCOA
+    w->repaint();
     [NSApp beginSheet:qt_mac_window_for(w) modalForWindow:qt_mac_window_for(w->parentWidget())
         modalDelegate:nil didEndSelector:nil contextInfo:0];
 #else
diff --git a/src/gui/kernel/qcocoaview_mac.mm b/src/gui/kernel/qcocoaview_mac.mm
index 13ff85b..e32fdeb 100644
--- a/src/gui/kernel/qcocoaview_mac.mm
+++ b/src/gui/kernel/qcocoaview_mac.mm
@@ -320,7 +320,7 @@ static int qCocoaViewCount = 0;
 
             }
 
-            CGContextFlush(context);
+            CGContextSynchronize(context);
             qt_mac_release_graphics_context(context);
             return;
         }
diff --git a/src/gui/kernel/qplatformclipboard_qpa.cpp b/src/gui/kernel/qplatformclipboard_qpa.cpp
index 7905185..f8e4b62 100644
--- a/src/gui/kernel/qplatformclipboard_qpa.cpp
+++ b/src/gui/kernel/qplatformclipboard_qpa.cpp
@@ -83,7 +83,7 @@ QPlatformClipboard::~QPlatformClipboard()
 
 }
 
-const QMimeData *QPlatformClipboard::mimeData(QClipboard::Mode mode) const
+QMimeData *QPlatformClipboard::mimeData(QClipboard::Mode mode)
 {
     //we know its clipboard
     Q_UNUSED(mode);
diff --git a/src/gui/kernel/qplatformclipboard_qpa.h b/src/gui/kernel/qplatformclipboard_qpa.h
index 41aa951..6a40fbc 100644
--- a/src/gui/kernel/qplatformclipboard_qpa.h
+++ b/src/gui/kernel/qplatformclipboard_qpa.h
@@ -59,7 +59,7 @@ class Q_GUI_EXPORT QPlatformClipboard
 public:
     virtual ~QPlatformClipboard();
 
-    virtual const QMimeData *mimeData(QClipboard::Mode mode = QClipboard::Clipboard ) const;
+    virtual QMimeData *mimeData(QClipboard::Mode mode = QClipboard::Clipboard);
     virtual void setMimeData(QMimeData *data, QClipboard::Mode mode = QClipboard::Clipboard);
     virtual bool supportsMode(QClipboard::Mode mode) const;
     void emitChanged(QClipboard::Mode mode);
diff --git a/src/gui/kernel/qwidget_qpa.cpp b/src/gui/kernel/qwidget_qpa.cpp
index a9bfba6..c7ce99a 100644
--- a/src/gui/kernel/qwidget_qpa.cpp
+++ b/src/gui/kernel/qwidget_qpa.cpp
@@ -731,12 +731,19 @@ QPlatformWindowFormat QWidget::platformWindowFormat() const
 {
     Q_D(const QWidget);
 
+    QPlatformWindowFormat format;
+
     QTLWExtra *extra = d->maybeTopData();
     if (extra){
-        return extra->platformWindowFormat;
+        format = extra->platformWindowFormat;
     } else {
-        return QPlatformWindowFormat::defaultFormat();
+        format = QPlatformWindowFormat::defaultFormat();
     }
+
+    if (testAttribute(Qt::WA_TranslucentBackground))
+        format.setAlpha(true);
+
+    return format;
 }
 
 void QWidgetPrivate::createSysExtra()