5 files changed, 22 insertions, 13 deletions

diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index 21ffe7d..dcac5ca 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -4027,11 +4027,18 @@ bool QGraphicsItemPrivate::isProxyWidget() const
 */
 void QGraphicsItem::update(const QRectF &rect)
 {
-    if ((rect.isEmpty() && !rect.isNull()) || d_ptr->discardUpdateRequest())
+    if (rect.isEmpty() && !rect.isNull())
         return;
 
     if (CacheMode(d_ptr->cacheMode) != NoCache) {
         QGraphicsItemCache *cache = d_ptr->extraItemCache();
+        if (d_ptr->discardUpdateRequest(/* ignoreVisibleBit = */ false,
+                                        /* ignoreClipping = */ false,
+                                        /* ignoreDirtyBit = */ true)) {
+            return;
+        }
+
+        // Invalidate cache.
         if (!cache->allExposed) {
             if (rect.isNull()) {
                 cache->allExposed = true;
@@ -4040,6 +4047,11 @@ void QGraphicsItem::update(const QRectF &rect)
                 cache->exposed.append(rect);
             }
         }
+        // Only invalidate cache; item is already dirty.
+        if (d_ptr->dirty)
+            return;
+    } else if (d_ptr->discardUpdateRequest()) {
+        return;
     }
 
     // Effectively the same as updateHelper(rect);
diff --git a/src/gui/graphicsview/qgraphicsproxywidget.cpp b/src/gui/graphicsview/qgraphicsproxywidget.cpp
index e660879..01b7593 100644
--- a/src/gui/graphicsview/qgraphicsproxywidget.cpp
+++ b/src/gui/graphicsview/qgraphicsproxywidget.cpp
@@ -460,7 +460,7 @@ void QGraphicsProxyWidgetPrivate::embedSubWindow(QWidget *subWin)
 {
     QWExtra *extra;
     if (!((extra = subWin->d_func()->extra) && extra->proxyWidget)) {
-        QGraphicsProxyWidget *subProxy = new QGraphicsProxyWidget(q_func());
+        QGraphicsProxyWidget *subProxy = new QGraphicsProxyWidget(q_func(), subWin->windowFlags());
         subProxy->d_func()->setWidget_helper(subWin, false);
     }
 }
@@ -544,6 +544,9 @@ QGraphicsProxyWidget::~QGraphicsProxyWidget()
     hidden or disabled after embedding is complete. The class documentation
     has a full overview over the shared state.
 
+    QGraphicsProxyWidget's window flags determine whether the widget, after
+    embedding, will be given window decorations or not.
+
     After this function returns, QGraphicsProxyWidget will keep its state
     synchronized with that of \a widget whenever possible.
 
@@ -661,10 +664,6 @@ void QGraphicsProxyWidgetPrivate::setWidget_helper(QWidget *newWidget, bool auto
     if (newWidget->testAttribute(Qt::WA_SetCursor))
         q->setCursor(widget->cursor());
 #endif
-    Qt::WFlags flags = newWidget->windowFlags();
-    if (newWidget->windowType() == Qt::Window)
-        flags &= ~Qt::Window;
-    q->setWindowFlags(flags);
     q->setEnabled(newWidget->isEnabled());
     q->setVisible(newWidget->isVisible());
     q->setLayoutDirection(newWidget->layoutDirection());
diff --git a/src/gui/graphicsview/qgraphicsscene.cpp b/src/gui/graphicsview/qgraphicsscene.cpp
index f90998f..f322305 100644
--- a/src/gui/graphicsview/qgraphicsscene.cpp
+++ b/src/gui/graphicsview/qgraphicsscene.cpp
@@ -4957,9 +4957,11 @@ void QGraphicsScenePrivate::drawItemHelper(QGraphicsItem *item, QPainter *painte
             if (newCacheIndent != deviceData->cacheIndent || deviceRect.size() != pix.size()) {
                 QPoint diff = newCacheIndent - deviceData->cacheIndent;
                 QPixmap newPix(deviceRect.size());
+                // ### Investigate removing this fill (test with Plasma and
+                // graphicssystem raster).
+                newPix.fill(Qt::transparent);
                 if (!pix.isNull()) {
                     QPainter newPixPainter(&newPix);
-                    newPixPainter.setCompositionMode(QPainter::CompositionMode_Source);
                     newPixPainter.drawPixmap(-diff, pix);
                     newPixPainter.end();
                 }
diff --git a/src/gui/graphicsview/qgraphicswidget.cpp b/src/gui/graphicsview/qgraphicswidget.cpp
index 2e7d82a..66930f2 100644
--- a/src/gui/graphicsview/qgraphicswidget.cpp
+++ b/src/gui/graphicsview/qgraphicswidget.cpp
@@ -1039,10 +1039,6 @@ QVariant QGraphicsWidget::itemChange(GraphicsItemChange change, const QVariant &
         break;
     }
     case ItemParentHasChanged: {
-        // reset window type on parent change in order to automagically remove decorations etc.
-        Qt::WindowFlags wflags = d->windowFlags & ~Qt::WindowType_Mask;
-        d->adjustWindowFlags(&wflags);
-        setWindowFlags(wflags);
         // Deliver ParentChange.
         QEvent event(QEvent::ParentChange);
         QApplication::sendEvent(this, &event);
@@ -1623,6 +1619,7 @@ void QGraphicsWidget::setWindowFlags(Qt::WindowFlags wFlags)
         return;
     bool wasPopup = (d->windowFlags & Qt::WindowType_Mask) == Qt::Popup;
 
+    d->adjustWindowFlags(&wFlags);
     d->windowFlags = wFlags;
     if (!d->setWindowFrameMargins)
         unsetWindowFrameMargins();
diff --git a/src/gui/graphicsview/qgraphicswidget_p.cpp b/src/gui/graphicsview/qgraphicswidget_p.cpp
index 06ffe73..4b41a31 100644
--- a/src/gui/graphicsview/qgraphicswidget_p.cpp
+++ b/src/gui/graphicsview/qgraphicswidget_p.cpp
@@ -67,8 +67,7 @@ void QGraphicsWidgetPrivate::init(QGraphicsItem *parentItem, Qt::WindowFlags wFl
     focusNext = focusPrev = q;
     focusPolicy = Qt::NoFocus;
 
-    if (!parentItem)
-        adjustWindowFlags(&wFlags);
+    adjustWindowFlags(&wFlags);
     windowFlags = wFlags;
 
     q->setParentItem(parentItem);