Merge branch '4.5' of git@scm.dev.nokia.troll.no:qt/qt into kinetic-statemachine

Conflicts:
	src/gui/graphicsview/qgraphicsitem.cpp

12 files changed, 973 insertions, 497 deletions

diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index d95b194..201dfb8 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -528,25 +528,22 @@ QT_BEGIN_NAMESPACE
 
 // QRectF::intersects() returns false always if either the source or target
 // rectangle's width or height are 0. This works around that problem.
-static QRectF _q_adjustedRect(const QRectF &rect)
-{
-    static const qreal p = (qreal)0.00001;
-    QRectF r = rect;
-    if (!r.width())
-        r.adjust(-p, 0, p, 0);
-    if (!r.height())
-        r.adjust(0, -p, 0, p);
-    return r;
+static inline void _q_adjustRect(QRectF *rect)
+{
+    Q_ASSERT(rect);
+    if (!rect->width())
+        rect->adjust(-0.00001, 0, 0.00001, 0);
+    if (!rect->height())
+        rect->adjust(0, -0.00001, 0, 0.00001);
 }
 
-static QRect _q_adjustedRect(const QRect &rect)
+static inline void _q_adjustRect(QRect *rect)
 {
-    QRect r = rect;
-    if (!r.width())
-        r.adjust(0, 0, 1, 0);
-    if (!r.height())
-        r.adjust(0, 0, 0, 1);
-    return r;
+    Q_ASSERT(rect);
+    if (!rect->width())
+        rect->adjust(0, 0, 1, 0);
+    if (!rect->height())
+        rect->adjust(0, 0, 0, 1);
 }
 
 /*
@@ -631,6 +628,7 @@ void QGraphicsItemPrivate::updateAncestorFlag(QGraphicsItem::GraphicsItemFlag ch
         case QGraphicsItem::ItemClipsChildrenToShape:
             flag = AncestorClipsChildren;
             enabled = flags & QGraphicsItem::ItemClipsChildrenToShape;
+            invalidateCachedClipPathRecursively(/*childrenOnly=*/true);
             break;
         case QGraphicsItem::ItemIgnoresTransformations:
             flag = AncestorIgnoresTransformations;
@@ -1028,9 +1026,8 @@ void QGraphicsItem::setParentItem(QGraphicsItem *parent)
     }
     if (parent == d_ptr->parent)
         return;
-    QVariant variant;
-    qVariantSetValue<QGraphicsItem *>(variant, parent);
-    parent = qVariantValue<QGraphicsItem *>(itemChange(ItemParentChange, variant));
+    const QVariant newParentVariant(itemChange(ItemParentChange, qVariantFromValue<QGraphicsItem *>(parent)));
+    parent = qVariantValue<QGraphicsItem *>(newParentVariant);
     if (parent == d_ptr->parent)
         return;
 
@@ -1045,11 +1042,11 @@ void QGraphicsItem::setParentItem(QGraphicsItem *parent)
     // We anticipate geometry changes
     prepareGeometryChange();
 
+    const QVariant thisPointerVariant(qVariantFromValue<QGraphicsItem *>(this));
     if (d_ptr->parent) {
         // Remove from current parent
         qt_graphicsitem_removeChild(this, &d_ptr->parent->d_func()->children);
-        qVariantSetValue<QGraphicsItem *>(variant, this);
-        d_ptr->parent->itemChange(ItemChildRemovedChange, variant);
+        d_ptr->parent->itemChange(ItemChildRemovedChange, thisPointerVariant);
     }
 
     if ((d_ptr->parent = parent)) {
@@ -1064,10 +1061,9 @@ void QGraphicsItem::setParentItem(QGraphicsItem *parent)
         }
 
         d_ptr->parent->d_func()->children << this;
-        qVariantSetValue<QGraphicsItem *>(variant, this);
-        d_ptr->parent->itemChange(ItemChildAddedChange, variant);
+        d_ptr->parent->itemChange(ItemChildAddedChange, thisPointerVariant);
         if (!implicitUpdate)
-            d_ptr->updateHelper();
+            d_ptr->updateHelper(QRectF(), false, true);
 
         // Inherit ancestor flags from the new parent.
         d_ptr->updateAncestorFlag(QGraphicsItem::GraphicsItemFlag(-1));
@@ -1096,7 +1092,7 @@ void QGraphicsItem::setParentItem(QGraphicsItem *parent)
         if (!d_ptr->enabled && !d_ptr->explicitlyDisabled)
             d_ptr->setEnabledHelper(true, /* explicit = */ false);
 
-        d_ptr->updateHelper();
+        d_ptr->updateHelper(QRectF(), false, true);
     }
 
     if (d_ptr->scene) {
@@ -1106,10 +1102,7 @@ void QGraphicsItem::setParentItem(QGraphicsItem *parent)
     }
 
     // Resolve opacity.
-    if (QGraphicsItem *p = d_ptr->parent)
-        d_ptr->resolveEffectiveOpacity(p->effectiveOpacity());
-    else
-        d_ptr->resolveEffectiveOpacity(1.0);
+    d_ptr->updateEffectiveOpacity();
 
     // Resolve depth.
     d_ptr->resolveDepth(parent ? parent->d_ptr->depth : -1);
@@ -1118,7 +1111,7 @@ void QGraphicsItem::setParentItem(QGraphicsItem *parent)
     d_ptr->invalidateSceneTransformCache();
 
     // Deliver post-change notification
-    itemChange(QGraphicsItem::ItemParentHasChanged, qVariantFromValue<QGraphicsItem *>(parent));
+    itemChange(QGraphicsItem::ItemParentHasChanged, newParentVariant);
 }
 
 /*!
@@ -1237,10 +1230,10 @@ void QGraphicsItem::setFlags(GraphicsItemFlags flags)
         return;
 
     // Flags that alter the geometry of the item (or its children).
-    int geomChangeFlagsMask = (ItemClipsChildrenToShape | ItemClipsToShape | ItemIgnoresTransformations);
-    bool fullUpdate = (flags & geomChangeFlagsMask) != (d_ptr->flags & geomChangeFlagsMask);
+    const quint32 geomChangeFlagsMask = (ItemClipsChildrenToShape | ItemClipsToShape | ItemIgnoresTransformations);
+    bool fullUpdate = (quint32(flags) & geomChangeFlagsMask) != (d_ptr->flags & geomChangeFlagsMask);
     if (fullUpdate)
-        d_ptr->fullUpdateHelper();
+        d_ptr->fullUpdateHelper(false, true);
 
     // Keep the old flags to compare the diff.
     GraphicsItemFlags oldFlags = this->flags();
@@ -1250,12 +1243,8 @@ void QGraphicsItem::setFlags(GraphicsItemFlags flags)
 
     // Reresolve effective opacity if the opacity flags change.
     static const quint32 opacityFlagsMask = ItemIgnoresParentOpacity | ItemDoesntPropagateOpacityToChildren;
-    if ((flags & opacityFlagsMask) != (oldFlags & opacityFlagsMask)) {
-        if (QGraphicsItem *p = d_ptr->parent)
-            d_ptr->resolveEffectiveOpacity(p->effectiveOpacity());
-        else
-            d_ptr->resolveEffectiveOpacity(1.0);
-    }
+    if ((flags & opacityFlagsMask) != (oldFlags & opacityFlagsMask))
+        d_ptr->updateEffectiveOpacity();
 
     if (!(d_ptr->flags & ItemIsFocusable) && hasFocus()) {
         // Clear focus on the item if it has focus when the focusable flag
@@ -1275,6 +1264,9 @@ void QGraphicsItem::setFlags(GraphicsItemFlags flags)
         d_ptr->updateAncestorFlag(ItemClipsChildrenToShape);
     }
 
+    if ((flags & ItemClipsToShape) != (oldFlags & ItemClipsToShape))
+        d_ptr->invalidateCachedClipPath();
+
     if ((flags & ItemIgnoresTransformations) != (oldFlags & ItemIgnoresTransformations)) {
         // Item children clipping changes. Propagate the ancestor flag to
         // all children.
@@ -1282,7 +1274,7 @@ void QGraphicsItem::setFlags(GraphicsItemFlags flags)
     }
 
     // ### Why updateHelper?
-    d_ptr->updateHelper();
+    d_ptr->updateHelper(QRectF(), false, true);
 
     // Notify change.
     itemChange(ItemFlagsHaveChanged, quint32(flags));
@@ -1380,9 +1372,9 @@ QString QGraphicsItem::toolTip() const
 */
 void QGraphicsItem::setToolTip(const QString &toolTip)
 {
-    QString newCursor = itemChange(ItemToolTipChange, toolTip).toString();
-    d_ptr->setExtra(QGraphicsItemPrivate::ExtraToolTip, toolTip);
-    itemChange(ItemToolTipHasChanged, toolTip);
+    const QVariant toolTipVariant(itemChange(ItemToolTipChange, toolTip));
+    d_ptr->setExtra(QGraphicsItemPrivate::ExtraToolTip, toolTipVariant.toString());
+    itemChange(ItemToolTipHasChanged, toolTipVariant);
 }
 #endif // QT_NO_TOOLTIP
 
@@ -1424,9 +1416,8 @@ QCursor QGraphicsItem::cursor() const
 */
 void QGraphicsItem::setCursor(const QCursor &cursor)
 {
-    QCursor newCursor = qVariantValue<QCursor>(itemChange(ItemCursorChange,
-                                                          qVariantFromValue<QCursor>(cursor)));
-    d_ptr->setExtra(QGraphicsItemPrivate::ExtraCursor, newCursor);
+    const QVariant cursorVariant(itemChange(ItemCursorChange, qVariantFromValue<QCursor>(cursor)));
+    d_ptr->setExtra(QGraphicsItemPrivate::ExtraCursor, qVariantValue<QCursor>(cursorVariant));
     d_ptr->hasCursor = 1;
     if (d_ptr->scene) {
         foreach (QGraphicsView *view, d_ptr->scene->views()) {
@@ -1443,7 +1434,7 @@ void QGraphicsItem::setCursor(const QCursor &cursor)
             }
         }
     }
-    itemChange(ItemCursorHasChanged, qVariantFromValue<QCursor>(newCursor));
+    itemChange(ItemCursorHasChanged, cursorVariant);
 }
 
 /*!
@@ -1537,14 +1528,20 @@ void QGraphicsItemPrivate::setVisibleHelper(bool newVisible, bool explicitly, bo
         return;
 
     // Modify the property.
-    newVisible = q_ptr->itemChange(QGraphicsItem::ItemVisibleChange, quint32(newVisible)).toBool();
+    const QVariant newVisibleVariant(q_ptr->itemChange(QGraphicsItem::ItemVisibleChange,
+                                                       quint32(newVisible)));
+    newVisible = newVisibleVariant.toBool();
     if (visible == quint32(newVisible))
         return;
     visible = newVisible;
 
     // Schedule redrawing
-    if (update)
+    if (update) {
+        QGraphicsItemCache *c = (QGraphicsItemCache *)qVariantValue<void *>(extra(ExtraCacheData));
+        if (c)
+            c->purge();
         updateHelper(QRectF(), /* force = */ true);
+    }
 
     // Certain properties are dropped as an item becomes invisible.
     if (!newVisible) {
@@ -1580,9 +1577,10 @@ void QGraphicsItemPrivate::setVisibleHelper(bool newVisible, bool explicitly, bo
     }
 
     // Update children with explicitly = false.
+    const bool updateChildren = update && !(flags & QGraphicsItem::ItemClipsChildrenToShape);
     foreach (QGraphicsItem *child, children) {
         if (!newVisible || !child->d_ptr->explicitlyHidden)
-            child->d_ptr->setVisibleHelper(newVisible, false);
+            child->d_ptr->setVisibleHelper(newVisible, false, updateChildren);
     }
 
     // Enable subfocus
@@ -1594,7 +1592,7 @@ void QGraphicsItemPrivate::setVisibleHelper(bool newVisible, bool explicitly, bo
     }
 
     // Deliver post-change notification.
-    q_ptr->itemChange(QGraphicsItem::ItemVisibleHasChanged, quint32(visible));
+    q_ptr->itemChange(QGraphicsItem::ItemVisibleHasChanged, newVisibleVariant);
 }
 
 /*!
@@ -1700,7 +1698,9 @@ void QGraphicsItemPrivate::setEnabledHelper(bool newEnabled, bool explicitly, bo
     }
 
     // Modify the property.
-    enabled = q_ptr->itemChange(QGraphicsItem::ItemEnabledChange, quint32(newEnabled)).toBool();
+    const QVariant newEnabledVariant(q_ptr->itemChange(QGraphicsItem::ItemEnabledChange,
+                                                       quint32(newEnabled)));
+    enabled = newEnabledVariant.toBool();
 
     // Schedule redraw.
     if (update)
@@ -1712,7 +1712,7 @@ void QGraphicsItemPrivate::setEnabledHelper(bool newEnabled, bool explicitly, bo
     }
 
     // Deliver post-change notification.
-    q_ptr->itemChange(QGraphicsItem::ItemEnabledHasChanged, quint32(enabled));
+    q_ptr->itemChange(QGraphicsItem::ItemEnabledHasChanged, newEnabledVariant);
 }
 
 /*!
@@ -1799,7 +1799,8 @@ void QGraphicsItem::setSelected(bool selected)
         selected = false;
     if (d_ptr->selected == selected)
         return;
-    bool newSelected = itemChange(ItemSelectedChange, quint32(selected)).toBool();
+    const QVariant newSelectedVariant(itemChange(ItemSelectedChange, quint32(selected)));
+    bool newSelected = newSelectedVariant.toBool();
     if (d_ptr->selected == newSelected)
         return;
     d_ptr->selected = newSelected;
@@ -1819,7 +1820,7 @@ void QGraphicsItem::setSelected(bool selected)
     }
 
     // Deliver post-change notification.
-    itemChange(QGraphicsItem::ItemSelectedHasChanged, quint32(d_ptr->selected));
+    itemChange(QGraphicsItem::ItemSelectedHasChanged, newSelectedVariant);
 }
 
 /*!
@@ -1863,6 +1864,9 @@ qreal QGraphicsItem::opacity() const
 */
 qreal QGraphicsItem::effectiveOpacity() const
 {
+    if (!d_ptr->hasEffectiveOpacity)
+        return qreal(1.0);
+
     QVariant effectiveOpacity = d_ptr->extra(QGraphicsItemPrivate::ExtraEffectiveOpacity);
     return effectiveOpacity.isNull() ? qreal(1.0) : qreal(effectiveOpacity.toDouble());
 }
@@ -1892,7 +1896,8 @@ qreal QGraphicsItem::effectiveOpacity() const
 void QGraphicsItem::setOpacity(qreal opacity)
 {
     // Notify change.
-    qreal newOpacity = itemChange(ItemOpacityChange, double(opacity)).toDouble();
+    const QVariant newOpacityVariant(itemChange(ItemOpacityChange, double(opacity)));
+    qreal newOpacity = newOpacityVariant.toDouble();
 
     // Normalize.
     newOpacity = qBound<qreal>(0.0, newOpacity, 1.0);
@@ -1921,7 +1926,7 @@ void QGraphicsItem::setOpacity(qreal opacity)
     itemChange(ItemOpacityHasChanged, newOpacity);
 
     // Update.
-    d_ptr->fullUpdateHelper();
+    d_ptr->fullUpdateHelper(/*childrenOnly=*/false, /*maybeDirtyClipPath=*/false, /*ignoreOpacity=*/true);
 }
 
 /*!
@@ -2350,19 +2355,22 @@ QPointF QGraphicsItem::scenePos() const
     the item is also updated; otherwise it is not updated before and after the
     change.
 */
-void QGraphicsItemPrivate::setPosHelper(const QPointF &pos, bool update)
+void QGraphicsItemPrivate::setPosHelper(const QPointF &pos)
 {
     Q_Q(QGraphicsItem);
     if (this->pos == pos)
         return;
 
     // Notify the item that the position is changing.
-    QPointF newPos = q->itemChange(QGraphicsItem::ItemPositionChange, pos).toPointF();
+    const QVariant newPosVariant(q->itemChange(QGraphicsItem::ItemPositionChange, pos));
+    QPointF newPos = newPosVariant.toPointF();
     if (newPos == this->pos)
         return;
 
     // Update and repositition.
-    if (scene && update) {
+    inSetPosHelper = 1;
+    updateCachedClipPathFromSetPosHelper(newPos);
+    if (scene) {
         fullUpdateHelper(true);
         q->prepareGeometryChange();
     }
@@ -2370,7 +2378,8 @@ void QGraphicsItemPrivate::setPosHelper(const QPointF &pos, bool update)
     invalidateSceneTransformCache();
 
     // Send post-notification.
-    q->itemChange(QGraphicsItem::ItemPositionHasChanged, newPos);
+    q->itemChange(QGraphicsItem::ItemPositionHasChanged, newPosVariant);
+    inSetPosHelper = 0;
 }
 
 /*!
@@ -2385,7 +2394,7 @@ void QGraphicsItemPrivate::setPosHelper(const QPointF &pos, bool update)
 */
 void QGraphicsItem::setPos(const QPointF &pos)
 {
-    d_ptr->setPosHelper(pos, /* update = */ true);
+    d_ptr->setPosHelper(pos);
 }
 
 /*!
@@ -2529,10 +2538,10 @@ QTransform QGraphicsItem::sceneTransform() const
     QTransform m;
     if (d_ptr->hasTransform) {
         m = transform();
-        m *= QTransform::fromTranslate(d_ptr->pos.x(), d_ptr->pos.y());
-    } else {
-        // ### ? QTransform::fromTranslate(d_ptr->pos.x(), d_ptr->pos.y())
-        m.translate(d_ptr->pos.x(), d_ptr->pos.y());
+        if (!d_ptr->pos.isNull())
+            m *= QTransform::fromTranslate(d_ptr->pos.x(), d_ptr->pos.y());
+    } else if (!d_ptr->pos.isNull()) {
+        m = QTransform::fromTranslate(d_ptr->pos.x(), d_ptr->pos.y());
     }
 
     // Combine with parent and add to cache.
@@ -2657,6 +2666,8 @@ QTransform QGraphicsItem::itemTransform(const QGraphicsItem *other, bool *ok) co
         if (ok)
             *ok = true;
         const QPointF &itemPos = d_ptr->pos;
+        if (itemPos.isNull())
+            return d_ptr->hasTransform ? transform() : QTransform();
         if (d_ptr->hasTransform)
             return transform() * QTransform::fromTranslate(itemPos.x(), itemPos.y());
         return QTransform::fromTranslate(itemPos.x(), itemPos.y());
@@ -2667,7 +2678,8 @@ QTransform QGraphicsItem::itemTransform(const QGraphicsItem *other, bool *ok) co
         const QPointF &otherPos = other->d_ptr->pos;
         if (other->d_ptr->hasTransform) {
             QTransform otherToParent = other->transform();
-            otherToParent *= QTransform::fromTranslate(otherPos.x(), otherPos.y());
+            if (!otherPos.isNull())
+                otherToParent *= QTransform::fromTranslate(otherPos.x(), otherPos.y());
             return otherToParent.inverted(ok);
         } else {
             if (ok)
@@ -2692,11 +2704,11 @@ QTransform QGraphicsItem::itemTransform(const QGraphicsItem *other, bool *ok) co
 
         QTransform itemToParent = QTransform::fromTranslate(itemPos.x(), itemPos.y());
         if (hasTr)
-            itemToParent = transform() * itemToParent;
+            itemToParent = itemPos.isNull() ? transform() : transform() * itemToParent;
 
         QTransform otherToParent = QTransform::fromTranslate(otherPos.x(), otherPos.y());
         if (otherHasTr)
-            otherToParent = other->transform() * otherToParent;
+            otherToParent = otherPos.isNull() ? other->transform() : other->transform() * otherToParent;
 
         return itemToParent * otherToParent.inverted(ok);
     }
@@ -2736,7 +2748,8 @@ QTransform QGraphicsItem::itemTransform(const QGraphicsItem *other, bool *ok) co
         const QGraphicsItemPrivate *pd = p->d_ptr;
         if (pd->hasTransform)
             x *= p->transform();
-        x *= QTransform::fromTranslate(pd->pos.x(), pd->pos.y());
+        if (!pd->pos.isNull())
+            x *= QTransform::fromTranslate(pd->pos.x(), pd->pos.y());
     } while ((p = p->d_ptr->parent) && p != root);
     if (parentOfOther)
         return x.inverted(ok);
@@ -2777,16 +2790,15 @@ void QGraphicsItem::setMatrix(const QMatrix &matrix, bool combine)
     if (oldTransform == newTransform)
         return;
 
-    // Notify the item that the transformation matrix is changing.
-    QVariant variant;
-    qVariantSetValue<QMatrix>(variant, newTransform.toAffine());
-    newTransform = QTransform(qVariantValue<QMatrix>(itemChange(ItemMatrixChange, variant)));
-
+    // Notify the item that the matrix is changing.
+    QVariant newTransformVariant(itemChange(ItemMatrixChange,
+                                            qVariantFromValue<QMatrix>(newTransform.toAffine())));
+    newTransform = QTransform(qVariantValue<QMatrix>(newTransformVariant));
     if (oldTransform == newTransform)
         return;
 
     // Update and set the new transformation.
-    d_ptr->fullUpdateHelper(true);
+    d_ptr->fullUpdateHelper(true, true);
     prepareGeometryChange();
     transformData->baseTransform = newTransform;
     transformData->dirty = true;
@@ -2794,7 +2806,9 @@ void QGraphicsItem::setMatrix(const QMatrix &matrix, bool combine)
     d_ptr->invalidateSceneTransformCache();
 
     // Send post-notification.
-    itemChange(ItemTransformHasChanged, newTransform);
+    // NB! We have to change the value from QMatrix to QTransform.
+    qVariantSetValue<QTransform>(newTransformVariant, newTransform);
+    itemChange(ItemTransformHasChanged, newTransformVariant);
 }
 
 /*!
@@ -2836,14 +2850,14 @@ void QGraphicsItem::setTransform(const QTransform &matrix, bool combine)
         return;
 
     // Notify the item that the transformation matrix is changing.
-    QVariant variant;
-    qVariantSetValue<QTransform>(variant, newTransform);
-    newTransform = qVariantValue<QTransform>(itemChange(ItemTransformChange, variant));
+    const QVariant newTransformVariant(itemChange(ItemTransformChange,
+                                                  qVariantFromValue<QTransform>(newTransform)));
+    newTransform = qVariantValue<QTransform>(newTransformVariant);
     if (oldTransform == newTransform)
         return;
 
     // Update and set the new transformation.
-    d_ptr->fullUpdateHelper(true);
+    d_ptr->fullUpdateHelper(true, true);
     prepareGeometryChange();
     transformData->baseTransform = newTransform;
     transformData->dirty = true;
@@ -2852,7 +2866,7 @@ void QGraphicsItem::setTransform(const QTransform &matrix, bool combine)
     d_ptr->invalidateSceneTransformCache();
 
     // Send post-notification.
-    itemChange(ItemTransformHasChanged, newTransform);
+    itemChange(ItemTransformHasChanged, newTransformVariant);
 }
 
 /*!
@@ -3191,7 +3205,8 @@ qreal QGraphicsItem::zValue() const
 */
 void QGraphicsItem::setZValue(qreal z)
 {
-    qreal newZ = qreal(itemChange(ItemZValueChange, double(z)).toDouble());
+    const QVariant newZVariant(itemChange(ItemZValueChange, double(z)));
+    qreal newZ = qreal(newZVariant.toDouble());
     if (newZ == d_ptr->z)
         return;
     d_ptr->z = z;
@@ -3203,7 +3218,7 @@ void QGraphicsItem::setZValue(qreal z)
         d_ptr->scene->d_func()->invalidateSortCache();
     }
 
-    itemChange(ItemZValueHasChanged, double(newZ));
+    itemChange(ItemZValueHasChanged, newZVariant);
 }
 
 /*!
@@ -3228,7 +3243,9 @@ QRectF QGraphicsItem::childrenBoundingRect() const
     QRectF childRect;
     foreach (QGraphicsItem *child, children()) {
         QPointF childPos = child->pos();
-        QTransform matrix = child->transform() * QTransform::fromTranslate(childPos.x(), childPos.y());
+        QTransform matrix = child->transform();
+        if (!childPos.isNull())
+            matrix *= QTransform::fromTranslate(childPos.x(), childPos.y());
         childRect |= matrix.mapRect(child->boundingRect() | child->childrenBoundingRect());
     }
     return childRect;
@@ -3360,57 +3377,79 @@ bool QGraphicsItem::isClipped() const
 QPainterPath QGraphicsItem::clipPath() const
 {
     Q_D(const QGraphicsItem);
-    QPainterPath clip;
-    if (!isClipped())
-        return clip;
+    if (!d->dirtyClipPath)
+        return d->emptyClipPath ? QPainterPath() : d->cachedClipPath;
+
+    if (!isClipped()) {
+        d_ptr->setCachedClipPath(QPainterPath());
+        return d->cachedClipPath;
+    }
+
+    const QRectF thisBoundingRect(boundingRect());
+    if (thisBoundingRect.isEmpty()) {
+        if (d_ptr->flags & ItemClipsChildrenToShape)
+            d_ptr->setEmptyCachedClipPathRecursively();
+        else
+            d_ptr->setEmptyCachedClipPath();
+        return QPainterPath();
+    }
 
+    QPainterPath clip;
     // Start with the item's bounding rect.
-    clip.addRect(boundingRect());
+    clip.addRect(thisBoundingRect);
 
-    bool clipAway = false;
     if (d->ancestorFlags & QGraphicsItemPrivate::AncestorClipsChildren) {
-        // Make list of parents up to the farthest ancestor that clips its
-        // children to its shape.
-        QVarLengthArray<const QGraphicsItem *, 32> clippingAncestors;
-        const QGraphicsItem *parent = parentItem();
-        const QGraphicsItem *clipOwner = 0;
-        do {
+        const QGraphicsItem *parent = this;
+        const QGraphicsItem *lastParent = this;
+
+        // Intersect any in-between clips starting at the top and moving downwards.
+        bool foundValidClipPath = false;
+        while ((parent = parent->d_ptr->parent)) {
             if (parent->d_ptr->flags & ItemClipsChildrenToShape) {
-                clippingAncestors.append(parent);
-                clipOwner = parent;
-            }
-        } while ((parent->d_ptr->ancestorFlags & QGraphicsItemPrivate::AncestorClipsChildren) && (parent = parent->parentItem()));
+                // Map clip to the current parent and intersect with its shape/clipPath
+                clip = lastParent->itemTransform(parent).map(clip);
+                if ((foundValidClipPath = !parent->d_ptr->dirtyClipPath && parent->isClipped())) {
+                    if (parent->d_ptr->emptyClipPath) {
+                        if (d_ptr->flags & ItemClipsChildrenToShape)
+                            d_ptr->setEmptyCachedClipPathRecursively();
+                        else
+                            d_ptr->setEmptyCachedClipPath();
+                        return QPainterPath();
+                    }
+                    clip = clip.intersected(parent->d_ptr->cachedClipPath);
+                    if (!(parent->d_ptr->flags & ItemClipsToShape))
+                        clip = clip.intersected(parent->shape());
+                } else {
+                    clip = clip.intersected(parent->shape());
+                }
 
-        // Start with the topmost clip.
-        QPainterPath parentClip = clipOwner->shape();
+                if (clip.isEmpty()) {
+                    if (d_ptr->flags & ItemClipsChildrenToShape)
+                        d_ptr->setEmptyCachedClipPathRecursively();
+                    else
+                        d_ptr->setEmptyCachedClipPath();
+                    return clip;
+                }
+                lastParent = parent;
+            }
 
-        // Intersect any in-between clips starting at the bottom and moving
-        // upwards.
-        for (int i = clippingAncestors.size() - 2; i >= 0; --i) {
-            const QGraphicsItem *item = clippingAncestors[i];
-            // ### what if itemtransform fails
-            if (clipOwner)
-                parentClip = clipOwner->itemTransform(item).map(parentClip);
-            parentClip = parentClip.intersected(item->shape());
-            if (parentClip.isEmpty()) {
-                clip = parentClip;
-                clipAway = true;
+            if (!(parent->d_ptr->ancestorFlags & QGraphicsItemPrivate::AncestorClipsChildren)
+                || foundValidClipPath) {
                 break;
             }
-            clipOwner = item;
         }
 
-        if (!clipAway) {
+        if (lastParent != this) {
+            // Map clip back to the item's transform.
             // ### what if itemtransform fails
-            clip = clip.intersected(clipOwner->itemTransform(this).map(parentClip));
-            if (clip.isEmpty())
-                clipAway = true;
+            clip = lastParent->itemTransform(this).map(clip);
         }
     }
 
-    if (!clipAway && d->flags & ItemClipsToShape)
+    if (d->flags & ItemClipsToShape)
         clip = clip.intersected(shape());
 
+    d_ptr->setCachedClipPath(clip);
     return clip;
 }
 
@@ -3432,10 +3471,16 @@ bool QGraphicsItem::contains(const QPointF &point) const
 }
 
 /*!
-    Returns true if this item collides with \a other; otherwise returns false.
-    The ways items collide is determined by \a mode. The default value for \a
-    mode is Qt::IntersectsItemShape; \a other collides with this item if it
-    either intersects, contains, or is contained by this item's shape.
+
+    Returns true if this item collides with \a other; otherwise
+    returns false.
+
+    The \a mode is applied to \a other, and the resulting shape or
+    bounding rectangle is then compared to this item's shape. The
+    default value for \a mode is Qt::IntersectsItemShape; \a other
+    collides with this item if it either intersects, contains, or is
+    contained by this item's shape (see Qt::ItemSelectionMode for
+    details).
 
     The default implementation is based on shape intersection, and it calls
     shape() on both items. Because the complexity of arbitrary shape-shape
@@ -3490,6 +3535,11 @@ bool QGraphicsItem::collidesWithItem(const QGraphicsItem *other, Qt::ItemSelecti
     Qt::IntersectsItemShape; \a path collides with this item if it either
     intersects, contains, or is contained by this item's shape.
 
+    Note that this function checks whether the item's shape or
+    bounding rectangle (depending on \a mode) is contained within \a
+    path, and not whether \a path is contained within the items shape
+    or bounding rectangle. 
+
     \sa collidesWithItem(), contains(), shape()
 */
 bool QGraphicsItem::collidesWithPath(const QPainterPath &path, Qt::ItemSelectionMode mode) const
@@ -3499,8 +3549,10 @@ bool QGraphicsItem::collidesWithPath(const QPainterPath &path, Qt::ItemSelection
         return false;
     }
 
-    QRectF rectA = _q_adjustedRect(boundingRect());
-    QRectF rectB = _q_adjustedRect(path.controlPointRect());
+    QRectF rectA(boundingRect());
+    _q_adjustRect(&rectA);
+    QRectF rectB(path.controlPointRect());
+    _q_adjustRect(&rectB);
     if (!rectA.intersects(rectB)) {
         // This we can determine efficiently. If the two rects neither
         // intersect nor contain eachother, then the two items do not collide.
@@ -3509,12 +3561,11 @@ bool QGraphicsItem::collidesWithPath(const QPainterPath &path, Qt::ItemSelection
 
     // For further testing, we need this item's shape or bounding rect.
     QPainterPath thisShape;
-    if (mode == Qt::IntersectsItemShape || mode == Qt::ContainsItemShape) {
+    if (mode == Qt::IntersectsItemShape || mode == Qt::ContainsItemShape)
         thisShape = (isClipped() && !d_ptr->localCollisionHack) ? clipPath() : shape();
-    } else {
-        thisShape.addPolygon(_q_adjustedRect(boundingRect()));
-        thisShape.closeSubpath();
-    }
+    else
+        thisShape.addRect(rectA);
+
     if (thisShape == QPainterPath()) {
         // Empty shape? No collision.
         return false;
@@ -3529,11 +3580,12 @@ bool QGraphicsItem::collidesWithPath(const QPainterPath &path, Qt::ItemSelection
 /*!
     Returns a list of all items that collide with this item.
 
-    The way collisions are detected is determined by \a mode. The default
-    value for \a mode is Qt::IntersectsItemShape; All items whose shape
-    intersects or is contained by this item's shape are returned.
+    The way collisions are detected is determined by applying \a mode
+    to items that are compared to this item, i.e., each item's shape
+    or bounding rectangle is checked against this item's shape. The
+    default value for \a mode is Qt::IntersectsItemShape.
 
-    \sa QGraphicsScene::collidingItems(), collidesWithItem()
+    \sa collidesWithItem()
 */
 QList<QGraphicsItem *> QGraphicsItem::collidingItems(Qt::ItemSelectionMode mode) const
 {
@@ -3684,7 +3736,8 @@ QRegion QGraphicsItem::boundingRegion(const QTransform &itemToDeviceTransform) c
     // into the bitmap, converts the result to a QRegion and scales the region
     // back to device space with inverse granularity.
     qreal granularity = boundingRegionGranularity();
-    QRect deviceRect = _q_adjustedRect(itemToDeviceTransform.mapRect(boundingRect()).toRect());
+    QRect deviceRect = itemToDeviceTransform.mapRect(boundingRect()).toRect();
+    _q_adjustRect(&deviceRect);
     if (granularity == 0.0)
         return QRegion(deviceRect);
 
@@ -3814,6 +3867,23 @@ void QGraphicsItem::setBoundingRegionGranularity(qreal granularity)
 
 /*!
     \internal
+    Returns true if we can discard an update request; otherwise false.
+*/
+bool QGraphicsItemPrivate::discardUpdateRequest(bool ignoreClipping, bool ignoreVisibleBit,
+                                                bool ignoreDirtyBit, bool ignoreOpacity) const
+{
+    // No scene, or if the scene is updating everything, means we have nothing
+    // to do. The only exception is if the scene tracks the growing scene rect.
+    return (!visible && !ignoreVisibleBit)
+           || (dirty && !ignoreDirtyBit)
+           || !scene
+           || (scene->d_func()->updateAll && scene->d_func()->hasSceneRect)
+           || (!ignoreClipping && (childrenClippedToShape() && isClippedAway()))
+           || (!ignoreOpacity && childrenCombineOpacity() && isFullyTransparent());
+}
+
+/*!
+    \internal
 
     Asks the scene to mark this item's scene rect as dirty, requesting a
     redraw.  This does not invalidate any cache.
@@ -3822,19 +3892,16 @@ void QGraphicsItem::setBoundingRegionGranularity(qreal granularity)
     only case where the item's background should be marked as dirty even when
     the item isn't visible.
 */
-void QGraphicsItemPrivate::updateHelper(const QRectF &rect, bool force)
+void QGraphicsItemPrivate::updateHelper(const QRectF &rect, bool force, bool maybeDirtyClipPath)
 {
     // No scene, or if the scene is updating everything, means we have nothing
     // to do. The only exception is if the scene tracks the growing scene rect.
-    if (dirty)
+    if (discardUpdateRequest(/*ignoreClipping=*/maybeDirtyClipPath, /*ignoreVisibleBit=*/force))
         return;
-    if (!scene || (scene && scene->d_func()->updateAll && scene->d_func()->hasSceneRect))
-        return;
-    if (scene && (visible || force)) {
-        if (rect.isNull())
-            dirty = 1;
-        scene->itemUpdated(q_ptr, rect);
-    }
+
+    if (rect.isNull())
+        dirty = 1;
+    scene->itemUpdated(q_ptr, rect);
 }
 
 /*!
@@ -3842,21 +3909,24 @@ void QGraphicsItemPrivate::updateHelper(const QRectF &rect, bool force)
 
     Propagates updates to \a item and all its children.
 */
-void QGraphicsItemPrivate::fullUpdateHelper(bool childrenOnly)
+void QGraphicsItemPrivate::fullUpdateHelper(bool childrenOnly, bool maybeDirtyClipPath, bool ignoreOpacity)
 {
-    // No scene, or if the scene is updating everything, means we have nothing
-    // to do. The only exception is if the scene tracks the growing scene rect.
-    if (!scene || (scene && scene->d_func()->updateAll && scene->d_func()->hasSceneRect))
-        return;
-    if (!childrenOnly && !dirty)
-        updateHelper();
-    if (children.isEmpty() || dirtyChildren)
+    if (discardUpdateRequest(/*ignoreClipping=*/maybeDirtyClipPath, /*ignoreVisibleBit=*/false,
+                             /*ignoreDirtyBit=*/true, ignoreOpacity)) {
         return;
-    if (flags & QGraphicsItem::ItemClipsChildrenToShape) {
-        // ### mark all children dirty?
+    }
+
+    if (!childrenOnly && !dirty) {
+        // Effectively the same as updateHelper(QRectF(), false, maybeDirtyClipPath).
+        dirty = 1;
+        scene->itemUpdated(q_ptr, QRectF());
+    }
+
+    if (dirtyChildren || childrenClippedToShape()) {
         // Unnecessary to update children as well.
         return;
     }
+
     if (ancestorFlags & AncestorClipsChildren) {
         Q_Q(QGraphicsItem);
         // Check if we can avoid updating all children.
@@ -3879,10 +3949,36 @@ void QGraphicsItemPrivate::fullUpdateHelper(bool childrenOnly)
         }
     }
     foreach (QGraphicsItem *child, children)
-        child->d_ptr->fullUpdateHelper();
+        child->d_ptr->fullUpdateHelper(false, maybeDirtyClipPath);
     dirtyChildren = 1;
 }
 
+static inline bool qt_allChildrenCombineOpacity(QGraphicsItem *parent)
+{
+    Q_ASSERT(parent);
+    if (parent->flags() & QGraphicsItem::ItemDoesntPropagateOpacityToChildren)
+        return false;
+
+    const QList<QGraphicsItem *> children(parent->childItems());
+    for (int i = 0; i < children.size(); ++i) {
+        if (children.at(i)->flags() & QGraphicsItem::ItemIgnoresParentOpacity)
+            return false;
+    }
+    return true;
+}
+
+void QGraphicsItemPrivate::updateEffectiveOpacity()
+{
+    Q_Q(QGraphicsItem);
+    if (parent) {
+        resolveEffectiveOpacity(parent->effectiveOpacity());
+        parent->d_ptr->allChildrenCombineOpacity = qt_allChildrenCombineOpacity(parent);
+    } else {
+        resolveEffectiveOpacity(1.0);
+    }
+    allChildrenCombineOpacity = qt_allChildrenCombineOpacity(q);
+}
+
 /*!
     \internal
 
@@ -3907,7 +4003,14 @@ void QGraphicsItemPrivate::resolveEffectiveOpacity(qreal parentEffectiveOpacity)
     }
 
     // Set this item's resolved opacity.
-    setExtra(ExtraEffectiveOpacity, myEffectiveOpacity);
+    if (qFuzzyCompare(myEffectiveOpacity, qreal(1.0))) {
+        // Opaque, unset effective opacity.
+        hasEffectiveOpacity = 0;
+        unsetExtra(ExtraEffectiveOpacity);
+    } else {
+        hasEffectiveOpacity = 1;
+        setExtra(ExtraEffectiveOpacity, myEffectiveOpacity);
+    }
 
     // Resolve children always.
     for (int i = 0; i < children.size(); ++i)
@@ -3960,6 +4063,109 @@ void QGraphicsItemPrivate::removeExtraItemCache()
     unsetExtra(ExtraCacheData);
 }
 
+void QGraphicsItemPrivate::setEmptyCachedClipPathRecursively(const QRectF &emptyIfOutsideThisRect)
+{
+    setEmptyCachedClipPath();
+
+    const bool checkRect = !emptyIfOutsideThisRect.isNull()
+                           && !(flags & QGraphicsItem::ItemClipsChildrenToShape);
+    for (int i = 0; i < children.size(); ++i) {
+        if (!checkRect) {
+            children.at(i)->d_ptr->setEmptyCachedClipPathRecursively();
+            continue;
+        }
+
+        QGraphicsItem *child = children.at(i);
+        const QRectF rect = child->mapRectFromParent(emptyIfOutsideThisRect);
+        if (rect.intersects(child->boundingRect()))
+            child->d_ptr->invalidateCachedClipPathRecursively(false, rect);
+        else
+            child->d_ptr->setEmptyCachedClipPathRecursively(rect);
+    }
+}
+
+void QGraphicsItemPrivate::invalidateCachedClipPathRecursively(bool childrenOnly, const QRectF &emptyIfOutsideThisRect)
+{
+    if (!childrenOnly)
+        invalidateCachedClipPath();
+
+    const bool checkRect = !emptyIfOutsideThisRect.isNull();
+    for (int i = 0; i < children.size(); ++i) {
+        if (!checkRect) {
+            children.at(i)->d_ptr->invalidateCachedClipPathRecursively(false);
+            continue;
+        }
+
+        QGraphicsItem *child = children.at(i);
+        const QRectF rect = child->mapRectFromParent(emptyIfOutsideThisRect);
+        if (rect.intersects(child->boundingRect()))
+            child->d_ptr->invalidateCachedClipPathRecursively(false, rect);
+        else
+            child->d_ptr->setEmptyCachedClipPathRecursively(rect);
+    }
+}
+
+void QGraphicsItemPrivate::updateCachedClipPathFromSetPosHelper(const QPointF &newPos)
+{
+    Q_ASSERT(inSetPosHelper);
+
+    if (!(ancestorFlags & QGraphicsItemPrivate::AncestorClipsChildren))
+        return; // Not clipped by any ancestor.
+
+    // Find closest clip ancestor and transform.
+    Q_Q(QGraphicsItem);
+    QTransform thisToParentTransform = hasTransform
+                                       ? q->transform() * QTransform::fromTranslate(newPos.x(), newPos.y())
+                                       : QTransform::fromTranslate(newPos.x(), newPos.y());
+    QGraphicsItem *clipParent = parent;
+    while (clipParent && !(clipParent->d_ptr->flags & QGraphicsItem::ItemClipsChildrenToShape)) {
+        if (clipParent->d_ptr->hasTransform)
+            thisToParentTransform *= clipParent->transform();
+        if (!clipParent->d_ptr->pos.isNull()) {
+            thisToParentTransform *= QTransform::fromTranslate(clipParent->d_ptr->pos.x(),
+                                                               clipParent->d_ptr->pos.y());
+        }
+        clipParent = clipParent->d_ptr->parent;
+    }
+
+    // thisToParentTransform is now the same as q->itemTransform(clipParent), except
+    // that the new position (which is not yet set on the item) is taken into account.
+    Q_ASSERT(clipParent);
+    Q_ASSERT(clipParent->d_ptr->flags & QGraphicsItem::ItemClipsChildrenToShape);
+
+    // From here everything is calculated in clip parent's coordinates.
+    const QRectF parentBoundingRect(clipParent->boundingRect());
+    const QRectF thisBoundingRect(thisToParentTransform.mapRect(q->boundingRect()));
+
+    if (!parentBoundingRect.intersects(thisBoundingRect)) {
+        // Item is moved outside the clip parent's bounding rect,
+        // i.e. it is fully clipped and the clip path is empty.
+        if (flags & QGraphicsItem::ItemClipsChildrenToShape)
+            setEmptyCachedClipPathRecursively();
+        else
+            setEmptyCachedClipPathRecursively(thisToParentTransform.inverted().mapRect(parentBoundingRect));
+        return;
+    }
+
+    const QPainterPath parentClip(clipParent->isClipped() ? clipParent->clipPath() : clipParent->shape());
+    if (parentClip.contains(thisBoundingRect))
+        return; // Item is inside the clip parent's shape. No update required.
+
+    const QRectF parentClipRect(parentClip.controlPointRect());
+    if (!parentClipRect.intersects(thisBoundingRect)) {
+        // Item is moved outside the clip parent's shape,
+        // i.e. it is fully clipped and the clip path is empty.
+        if (flags & QGraphicsItem::ItemClipsChildrenToShape)
+            setEmptyCachedClipPathRecursively();
+        else
+            setEmptyCachedClipPathRecursively(thisToParentTransform.inverted().mapRect(parentClipRect));
+    } else {
+        // Item is partially inside the clip parent's shape,
+        // i.e. the cached clip path must be invalidated.
+        invalidateCachedClipPathRecursively(false, thisToParentTransform.inverted().mapRect(parentClipRect));
+    }
+}
+
 /*!
     \internal
 
@@ -3990,20 +4196,35 @@ bool QGraphicsItemPrivate::isProxyWidget() const
 */
 void QGraphicsItem::update(const QRectF &rect)
 {
-    if (d_ptr->dirty)
+    if (rect.isEmpty() && !rect.isNull())
         return;
-    if (d_ptr->scene && isVisible()) {
-        if (CacheMode(d_ptr->cacheMode) != NoCache) {
-            QGraphicsItemCache *cache = d_ptr->extraItemCache();
-            if (rect.isNull()) {
-                cache->allExposed = true;
-                cache->exposed.clear();
-            } else {
-                cache->exposed.append(rect);
-            }
+
+    if (CacheMode(d_ptr->cacheMode) != NoCache) {
+        QGraphicsItemCache *cache = d_ptr->extraItemCache();
+        if (d_ptr->discardUpdateRequest(/* ignoreVisibleBit = */ false,
+                                        /* ignoreClipping = */ false,
+                                        /* ignoreDirtyBit = */ true)) {
+            return;
         }
-        d_ptr->updateHelper(rect);
+
+        // Invalidate cache.
+        if (rect.isNull()) {
+            cache->allExposed = true;
+            cache->exposed.clear();
+        } else {
+            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);
+    if (rect.isNull())
+        d_ptr->dirty = 1;
+    d_ptr->scene->itemUpdated(this, rect);
 }
 
 
@@ -4260,9 +4481,9 @@ QPolygonF QGraphicsItem::mapToItem(const QGraphicsItem *item, const QRectF &rect
 */
 QPolygonF QGraphicsItem::mapToParent(const QRectF &rect) const
 {
-    if (!d_ptr->hasTransform)
-        return QPolygonF(rect.translated(d_ptr->pos));
-    return transform().map(rect.translated(d_ptr->pos));
+    QPolygonF p = !d_ptr->hasTransform ? rect : transform().map(rect);
+    p.translate(d_ptr->pos);
+    return p;
 }
 
 /*!
@@ -4329,8 +4550,8 @@ QRectF QGraphicsItem::mapRectToItem(const QGraphicsItem *item, const QRectF &rec
 */
 QRectF QGraphicsItem::mapRectToParent(const QRectF &rect) const
 {
-    QRectF r = rect.translated(d_ptr->pos.x(), d_ptr->pos.y());
-    return !d_ptr->hasTransform ? r : transform().mapRect(r);
+    QRectF r = !d_ptr->hasTransform ? rect : transform().mapRect(rect);
+    return r.translated(d_ptr->pos);
 }
 
 /*!
@@ -4461,9 +4682,9 @@ QPolygonF QGraphicsItem::mapToItem(const QGraphicsItem *item, const QPolygonF &p
 */
 QPolygonF QGraphicsItem::mapToParent(const QPolygonF &polygon) const
 {
-    QPolygonF p = polygon;
+    QPolygonF p = !d_ptr->hasTransform ? polygon : transform().map(polygon);
     p.translate(d_ptr->pos);
-    return d_ptr->hasTransform ? transform().map(p) : p;
+    return p;
 }
 
 /*!
@@ -4505,7 +4726,10 @@ QPainterPath QGraphicsItem::mapToItem(const QGraphicsItem *item, const QPainterP
 */
 QPainterPath QGraphicsItem::mapToParent(const QPainterPath &path) const
 {
-    return d_ptr->parent ? itemTransform(d_ptr->parent).map(path) : mapToScene(path);
+    QTransform x = QTransform::fromTranslate(d_ptr->pos.x(), d_ptr->pos.y());
+    if (d_ptr->hasTransform)
+        x = transform() * x;
+    return x.map(path);
 }
 
 /*!
@@ -5735,11 +5959,18 @@ void QGraphicsItem::removeFromIndex()
 void QGraphicsItem::prepareGeometryChange()
 {
     if (d_ptr->scene) {
-        d_ptr->updateHelper();
-
+        d_ptr->updateHelper(QRectF(), false, /*maybeDirtyClipPath=*/!d_ptr->inSetPosHelper);
         QGraphicsScenePrivate *scenePrivate = d_ptr->scene->d_func();
         scenePrivate->removeFromIndex(this);
     }
+
+    if (d_ptr->inSetPosHelper)
+        return;
+
+    if (d_ptr->flags & ItemClipsChildrenToShape)
+        d_ptr->invalidateCachedClipPathRecursively();
+    else
+        d_ptr->invalidateCachedClipPath();
 }
 
 /*!
@@ -7253,6 +7484,7 @@ QVariant QGraphicsLineItem::extension(const QVariant &variant) const
     QPixmap::createHeuristicMask().  The performance and memory consumption
     is similar to MaskShape.
 */
+extern QPainterPath qt_regionToPath(const QRegion &region);
 
 class QGraphicsPixmapItemPrivate : public QGraphicsItemPrivate
 {
@@ -7273,7 +7505,6 @@ public:
 
     void updateShape()
     {
-        extern QPainterPath qt_regionToPath(const QRegion &region);
         shape = QPainterPath();
         switch (shapeMode) {
         case QGraphicsPixmapItem::MaskShape: {
@@ -8323,6 +8554,8 @@ void QGraphicsTextItem::setTabChangesFocus(bool b)
     Returns true if the \gui Tab key will cause the widget to change focus;
     otherwise, false is returned.
 
+    By default, this behavior is disabled, and this function will return false.
+
     \sa setTabChangesFocus()
 */
 bool QGraphicsTextItem::tabChangesFocus() const
@@ -8514,6 +8747,7 @@ void QGraphicsSimpleTextItem::setText(const QString &text)
         return;
     d->text = text;
     d->updateBoundingRect();
+    update();
 }
 
 /*!
@@ -8775,13 +9009,17 @@ void QGraphicsItemGroup::addToGroup(QGraphicsItem *item)
     QTransform oldSceneMatrix = item->sceneTransform();
     item->setPos(mapFromItem(item, 0, 0));
     item->setParentItem(this);
-    item->setTransform(oldSceneMatrix
-                       * sceneTransform().inverted()
-                       * QTransform::fromTranslate(-item->x(), -item->y()));
+    QTransform newItemTransform(oldSceneMatrix);
+    newItemTransform *= sceneTransform().inverted();
+    if (!item->pos().isNull())
+        newItemTransform *= QTransform::fromTranslate(-item->x(), -item->y());
+    item->setTransform(newItemTransform);
     item->d_func()->setIsMemberOfGroup(true);
     prepareGeometryChange();
-    d->itemsBoundingRect |= (item->transform() * QTransform::fromTranslate(item->x(), item->y()))
-                            .mapRect(item->boundingRect() | item->childrenBoundingRect());
+    QTransform itemTransform(item->transform());
+    if (!item->pos().isNull())
+        itemTransform *= QTransform::fromTranslate(item->x(), item->y());
+    d->itemsBoundingRect |= itemTransform.mapRect(item->boundingRect() | item->childrenBoundingRect());
     update();
 }
 
diff --git a/src/gui/graphicsview/qgraphicsitem_p.h b/src/gui/graphicsview/qgraphicsitem_p.h
index c14b978..e8ab63d 100644
--- a/src/gui/graphicsview/qgraphicsitem_p.h
+++ b/src/gui/graphicsview/qgraphicsitem_p.h
@@ -142,10 +142,15 @@ public:
         hasBoundingRegionGranularity(0),
         flags(0),
         hasOpacity(0),
+        hasEffectiveOpacity(0),
         isWidget(0),
         dirty(0),
         dirtyChildren(0),
         localCollisionHack(0),
+        dirtyClipPath(1),
+        emptyClipPath(0),
+        inSetPosHelper(0),
+        allChildrenCombineOpacity(1),
         globalStackingOrder(-1),
         sceneTransformIndex(-1),
         q_ptr(0)
@@ -166,11 +171,14 @@ public:
     virtual QVariant inputMethodQueryHelper(Qt::InputMethodQuery query) const;
     static bool movableAncestorIsSelected(const QGraphicsItem *item);
 
-    void setPosHelper(const QPointF &pos, bool update);
+    void setPosHelper(const QPointF &pos);
     void setVisibleHelper(bool newVisible, bool explicitly, bool update = true);
     void setEnabledHelper(bool newEnabled, bool explicitly, bool update = true);
-    void updateHelper(const QRectF &rect = QRectF(), bool force = false);
-    void fullUpdateHelper(bool childrenOnly = false);
+    bool discardUpdateRequest(bool ignoreClipping = false, bool ignoreVisibleBit = false,
+                              bool ignoreDirtyBit = false, bool ignoreOpacity = false) const;
+    void updateHelper(const QRectF &rect = QRectF(), bool force = false, bool maybeDirtyClipPath = false);
+    void fullUpdateHelper(bool childrenOnly = false, bool maybeDirtyClipPath = false, bool ignoreOpacity = false);
+    void updateEffectiveOpacity();
     void resolveEffectiveOpacity(qreal effectiveParentOpacity);
     void resolveDepth(int parentDepth);
     void invalidateSceneTransformCache();
@@ -243,6 +251,47 @@ public:
     QGraphicsItemCache *extraItemCache() const;
     void removeExtraItemCache();
 
+    inline void setCachedClipPath(const QPainterPath &path)
+    {
+        cachedClipPath = path;
+        dirtyClipPath = 0;
+        emptyClipPath = 0;
+    }
+
+    inline void setEmptyCachedClipPath()
+    {
+        emptyClipPath = 1;
+        dirtyClipPath = 0;
+    }
+
+    void setEmptyCachedClipPathRecursively(const QRectF &emptyIfOutsideThisRect = QRectF());
+
+    inline void invalidateCachedClipPath()
+    { /*static int count = 0 ;qWarning("%i", ++count);*/ dirtyClipPath = 1; emptyClipPath = 0; }
+
+    void invalidateCachedClipPathRecursively(bool childrenOnly = false, const QRectF &emptyIfOutsideThisRect = QRectF());
+    void updateCachedClipPathFromSetPosHelper(const QPointF &newPos);
+
+    inline bool isFullyTransparent() const
+    { return hasEffectiveOpacity && qFuzzyCompare(q_func()->effectiveOpacity() + 1, qreal(1.0)); }
+
+    inline bool childrenCombineOpacity() const
+    { return allChildrenCombineOpacity || children.isEmpty(); }
+
+    inline bool isClippedAway() const
+    { return !dirtyClipPath && q_func()->isClipped() && (emptyClipPath || cachedClipPath.isEmpty()); }
+
+    inline bool childrenClippedToShape() const
+    { return (flags & QGraphicsItem::ItemClipsChildrenToShape) || children.isEmpty(); }
+
+    inline bool isInvisible() const
+    {
+        return !visible
+               || (childrenClippedToShape() && isClippedAway())
+               || (childrenCombineOpacity() && isFullyTransparent());
+    }
+
+    QPainterPath cachedClipPath;
     QPointF pos;
     qreal z;
     QGraphicsScene *scene;
@@ -272,10 +321,15 @@ public:
 
     // New 32 bytes
     quint32 hasOpacity : 1;
+    quint32 hasEffectiveOpacity : 1;
     quint32 isWidget : 1;
     quint32 dirty : 1;    
     quint32 dirtyChildren : 1;    
     quint32 localCollisionHack : 1;
+    quint32 dirtyClipPath : 1;
+    quint32 emptyClipPath : 1;
+    quint32 inSetPosHelper : 1;
+    quint32 allChildrenCombineOpacity : 1;
 
     // Optional stacking order
     int globalStackingOrder;
diff --git a/src/gui/graphicsview/qgraphicslayoutitem.cpp b/src/gui/graphicsview/qgraphicslayoutitem.cpp
index 0ea7692..eaa97ff 100644
--- a/src/gui/graphicsview/qgraphicslayoutitem.cpp
+++ b/src/gui/graphicsview/qgraphicslayoutitem.cpp
@@ -117,7 +117,7 @@ QGraphicsLayoutItemPrivate::QGraphicsLayoutItemPrivate(QGraphicsLayoutItem *par,
 */
 void QGraphicsLayoutItemPrivate::init()
 {
-    sizeHintCacheDirty = true; 
+    sizeHintCacheDirty = true;
     sizePolicy = QSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred);
 }
 
@@ -175,12 +175,12 @@ QSizeF *QGraphicsLayoutItemPrivate::effectiveSizeHints(const QSizeF &constraint)
 
     Returns the parent item of this layout, or 0 if this layout is
     not installed on any widget.
-    
+
     If this is the item that the layout is installed on, it will return "itself".
 
     If the layout is a sub-layout, this function returns the parent
     widget of the parent layout.
-    
+
     Note that it will traverse up the layout item hierarchy instead of just calling
     QGraphicsItem::parentItem(). This is on purpose.
 
@@ -233,7 +233,7 @@ QGraphicsItem *QGraphicsLayoutItemPrivate::parentItem() const
     position. Calling setGeometry() will always resize and reposition the item
     immediately. Normally, this function is called by QGraphicsLayout after
     the layout has been activated, but it can also be called by the item's user
-    at any time. 
+    at any time.
 
     The sizeHint() function returns the item' minimum, preferred and maximum
     size hints. You can override these properties by calling setMinimumSize(),
@@ -360,7 +360,7 @@ void QGraphicsLayoutItem::setSizePolicy(QSizePolicy::Policy hPolicy,
 }
 
 /*!
-    Returns the current size policy. 
+    Returns the current size policy.
 
     \sa setSizePolicy(), QWidget::sizePolicy()
 */
@@ -626,14 +626,15 @@ void QGraphicsLayoutItem::setMaximumHeight(qreal height)
 */
 
 /*!
-    \fn virtual void QGraphicsLayoutItem::setGeometry(const QRectF &rect) = 0
+    \fn virtual void QGraphicsLayoutItem::setGeometry(const QRectF &rect)
 
-    This pure virtual function sets the geometry of the QGraphicsLayoutItem to
+    This virtual function sets the geometry of the QGraphicsLayoutItem to
     \a rect, which is in parent coordinates (e.g., the top-left corner of \a rect
     is equivalent to the item's position in parent coordinates).
 
-    Reimplement this function in a subclass of QGraphicsLayoutItem to enable
-    your item to receive geometry updates.
+    You must reimplement this function in a subclass of QGraphicsLayoutItem to
+    receive geometry updates. The layout will call this function when it does a 
+    rearrangement.
 
     If \a rect is outside of the bounds of minimumSize and maximumSize, it
     will be adjusted to its closest size so that it is within the legal
@@ -744,7 +745,7 @@ QSizeF QGraphicsLayoutItem::effectiveSizeHint(Qt::SizeHint which, const QSizeF &
     \sa effectiveSizeHint()
 */
 void QGraphicsLayoutItem::updateGeometry()
-{ 
+{
     Q_D(QGraphicsLayoutItem);
     d->sizeHintCacheDirty = true;
 }
@@ -768,7 +769,7 @@ QGraphicsLayoutItem *QGraphicsLayoutItem::parentLayoutItem() const
     \sa parentLayoutItem()
 */
 void QGraphicsLayoutItem::setParentLayoutItem(QGraphicsLayoutItem *parent)
-{ 
+{
     d_func()->parent = parent;
 }
 
@@ -789,12 +790,12 @@ bool QGraphicsLayoutItem::isLayout() const
     If its true, then the layout will delete it. If its false, then it is
     assumed that another object has the ownership of it, and the layout won't
     delete this item.
-    
-    If the item inherits both QGraphicsItem and QGraphicsLayoutItem (such 
-    as QGraphicsWidget does) the item is really part of two ownership 
+
+    If the item inherits both QGraphicsItem and QGraphicsLayoutItem (such
+    as QGraphicsWidget does) the item is really part of two ownership
     hierarchies. This property informs what the layout should do with its
     child items when it is destructed. In the case of QGraphicsWidget, it
-    is preferred that when the layout is deleted it won't delete its children 
+    is preferred that when the layout is deleted it won't delete its children
     (since they are also part of the graphics item hierarchy).
 
     By default this value is initialized to false in QGraphicsLayoutItem,
@@ -822,9 +823,9 @@ void QGraphicsLayoutItem::setOwnedByLayout(bool ownership)
 
 /*!
  * Returns the QGraphicsItem that this layout item represents.
- * For QGraphicsWidget it will return itself. For custom items it can return an 
- * aggregated value. 
- * 
+ * For QGraphicsWidget it will return itself. For custom items it can return an
+ * aggregated value.
+ *
  * \sa setGraphicsItem()
  */
 QGraphicsItem *QGraphicsLayoutItem::graphicsItem() const
@@ -836,10 +837,10 @@ QGraphicsItem *QGraphicsLayoutItem::graphicsItem() const
  * If the QGraphicsLayoutItem represents a QGraphicsItem, and it wants to take
  * advantage of the automatic reparenting capabilities of QGraphicsLayout it
  * should set this value.
- * Note that if you delete \a item and not delete the layout item, you are 
- * responsible of calling setGraphicsItem(0) in order to avoid having a 
+ * Note that if you delete \a item and not delete the layout item, you are
+ * responsible of calling setGraphicsItem(0) in order to avoid having a
  * dangling pointer.
- * 
+ *
  * \sa graphicsItem()
  */
 void QGraphicsLayoutItem::setGraphicsItem(QGraphicsItem *item)
@@ -848,5 +849,5 @@ void QGraphicsLayoutItem::setGraphicsItem(QGraphicsItem *item)
 }
 
 QT_END_NAMESPACE
-        
+
 #endif //QT_NO_GRAPHICSVIEW
diff --git a/src/gui/graphicsview/qgraphicsproxywidget.cpp b/src/gui/graphicsview/qgraphicsproxywidget.cpp
index 1bd2e21..973254f 100644
--- a/src/gui/graphicsview/qgraphicsproxywidget.cpp
+++ b/src/gui/graphicsview/qgraphicsproxywidget.cpp
@@ -177,6 +177,10 @@ QT_BEGIN_NAMESPACE
     while the widget is embedded. In this state, the widget may differ slightly
     in behavior from when it is not embedded.
 
+    \warning This class is provided for convenience when bridging
+    QWidgets and QGraphicsItems, it should not be used for
+    high-performance scenarios.
+
     \sa QGraphicsScene::addWidget(), QGraphicsWidget
 */
 
@@ -1034,7 +1038,7 @@ void QGraphicsProxyWidget::dragMoveEvent(QGraphicsSceneDragDropEvent *event)
         if (receiver != d->dragDropWidget) {
             // Try to enter before we leave
             QDragEnterEvent dragEnter(receiverPos, event->possibleActions(), event->mimeData(), event->buttons(), event->modifiers());
-            dragEnter.setDropAction(event->proposedAction());            
+            dragEnter.setDropAction(event->proposedAction());
             QApplication::sendEvent(receiver, &dragEnter);
             event->setAccepted(dragEnter.isAccepted());
             event->setDropAction(dragEnter.dropAction());
@@ -1433,7 +1437,7 @@ int QGraphicsProxyWidget::type() const
 
   Creates a proxy widget for the given \a child of the widget
   contained in this proxy.
-  
+
   This function makes it possible to aquire proxies for
   non top-level widgets. For instance, you can embed a dialog,
   and then transform only one of its widgets.
diff --git a/src/gui/graphicsview/qgraphicsscene.cpp b/src/gui/graphicsview/qgraphicsscene.cpp
index 1f78a18..13f70e5 100644
--- a/src/gui/graphicsview/qgraphicsscene.cpp
+++ b/src/gui/graphicsview/qgraphicsscene.cpp
@@ -292,15 +292,21 @@ static inline bool QRectF_intersects(const QRectF &s, const QRectF &r)
 
 // QRectF::intersects() returns false always if either the source or target
 // rectangle's width or height are 0. This works around that problem.
-static QRectF _q_adjustedRect(const QRectF &rect)
+static inline void _q_adjustRect(QRectF *rect)
 {
-    static const qreal p = (qreal)0.00001;
-    QRectF r = rect;
-    if (!r.width())
-        r.adjust(-p, 0, p, 0);
-    if (!r.height())
-        r.adjust(0, -p, 0, p);
-    return r;
+    Q_ASSERT(rect);
+    if (!rect->width())
+        rect->adjust(-0.00001, 0, 0.00001, 0);
+    if (!rect->height())
+        rect->adjust(0, -0.00001, 0, 0.00001);
+}
+
+static inline QRectF adjustedItemBoundingRect(const QGraphicsItem *item)
+{
+    Q_ASSERT(item);
+    QRectF boundingRect(item->boundingRect());
+    _q_adjustRect(&boundingRect);
+    return boundingRect;
 }
 
 static void _q_hoverFromMouseEvent(QGraphicsSceneHoverEvent *hover, const QGraphicsSceneMouseEvent *mouseEvent)
@@ -632,10 +638,11 @@ void QGraphicsScenePrivate::_q_updateLater()
 */
 void QGraphicsScenePrivate::_q_polishItems()
 {
+    const QVariant booleanTrueVariant(true);
     foreach (QGraphicsItem *item, unpolishedItems) {
         if (!item->d_ptr->explicitlyHidden) {
-            item->itemChange(QGraphicsItem::ItemVisibleChange, true);
-            item->itemChange(QGraphicsItem::ItemVisibleHasChanged, true);
+            item->itemChange(QGraphicsItem::ItemVisibleChange, booleanTrueVariant);
+            item->itemChange(QGraphicsItem::ItemVisibleHasChanged, booleanTrueVariant);
         }
         if (item->isWidget()) {
             QEvent event(QEvent::Polish);
@@ -690,13 +697,6 @@ void QGraphicsScenePrivate::_q_removeItemLater(QGraphicsItem *item)
 {
     Q_Q(QGraphicsScene);
 
-    if (QGraphicsItem *parent = item->d_func()->parent) {
-        QVariant variant;
-        qVariantSetValue<QGraphicsItem *>(variant, item);
-        parent->itemChange(QGraphicsItem::ItemChildRemovedChange, variant);
-        parent->d_func()->children.removeAll(item);
-    }
-
     // Clear focus on the item to remove any reference in the focusWidget
     // chain.
     item->clearFocus();
@@ -740,6 +740,15 @@ void QGraphicsScenePrivate::_q_removeItemLater(QGraphicsItem *item)
     unpolishedItems.removeAll(item);
     dirtyItems.removeAll(item);
 
+    //We remove all references of item from the sceneEventFilter arrays
+    QMultiMap<QGraphicsItem*, QGraphicsItem*>::iterator iterator = sceneEventFilters.begin();
+    while (iterator != sceneEventFilters.end()) {
+        if (iterator.value() == item || iterator.key() == item)
+            iterator = sceneEventFilters.erase(iterator);
+        else
+            ++iterator;
+    }
+
     // Remove from scene transform cache
     int transformIndex = item->d_func()->sceneTransformIndex;
     if (transformIndex != -1) {
@@ -1358,6 +1367,48 @@ QGraphicsWidget *QGraphicsScenePrivate::windowForItem(const QGraphicsItem *item)
     return 0;
 }
 
+
+QList<QGraphicsItem *> QGraphicsScenePrivate::items_helper(const QPointF &pos) const
+{
+    QList<QGraphicsItem *> items;
+
+    // The index returns a rough estimate of what items are inside the rect.
+    // Refine it by iterating through all returned items.
+    QRectF adjustedRect = QRectF(pos, QSize(1,1));
+    foreach (QGraphicsItem *item, estimateItemsInRect(adjustedRect)) {
+        // Find the item's scene transform in a clever way.
+        QTransform x = item->sceneTransform();
+        bool keep = false;
+
+        // ### _q_adjustedRect is only needed because QRectF::intersects,
+        // QRectF::contains and QTransform::map() and friends don't work with
+        // flat rectangles.
+        const QRectF br(adjustedItemBoundingRect(item));
+            // Rect intersects/contains item's shape
+        if (QRectF_intersects(adjustedRect, x.mapRect(br))) {
+            bool ok;
+            QTransform xinv = x.inverted(&ok);
+            if (ok) {
+                if (item->contains(xinv.map(pos))) {
+                    items << item;
+                    keep = true;
+                }
+            }
+        }
+
+        if (keep && (item->flags() & QGraphicsItem::ItemClipsChildrenToShape)) {
+            // Recurse into children that clip children.
+            bool ok;
+            QTransform xinv = x.inverted(&ok);
+            if (ok)
+                childItems_helper(&items, item, xinv.map(pos));
+        }
+    }
+
+    sortItems(&items, Qt::AscendingOrder, sortCacheEnabled);
+    return items;
+}
+
 QList<QGraphicsItem *> QGraphicsScenePrivate::items_helper(const QRectF &rect,
                                                            Qt::ItemSelectionMode mode,
                                                            Qt::SortOrder order) const
@@ -1368,7 +1419,8 @@ QList<QGraphicsItem *> QGraphicsScenePrivate::items_helper(const QRectF &rect,
 
     // The index returns a rough estimate of what items are inside the rect.
     // Refine it by iterating through all returned items.
-    QRectF adjustedRect = _q_adjustedRect(rect);
+    QRectF adjustedRect(rect);
+    _q_adjustRect(&adjustedRect);
     foreach (QGraphicsItem *item, estimateItemsInRect(adjustedRect)) {
         // Find the item's scene transform in a clever way.
         QTransform x = item->sceneTransform();
@@ -1377,7 +1429,7 @@ QList<QGraphicsItem *> QGraphicsScenePrivate::items_helper(const QRectF &rect,
         // ### _q_adjustedRect is only needed because QRectF::intersects,
         // QRectF::contains and QTransform::map() and friends don't work with
         // flat rectangles.
-        QRectF br = _q_adjustedRect(item->boundingRect());
+        const QRectF br(adjustedItemBoundingRect(item));
         if (mode >= Qt::ContainsItemBoundingRect) {
             // Rect intersects/contains item's bounding rect
             QRectF mbr = x.mapRect(br);
@@ -1392,7 +1444,7 @@ QList<QGraphicsItem *> QGraphicsScenePrivate::items_helper(const QRectF &rect,
                 bool ok;
                 QTransform xinv = x.inverted(&ok);
                 if (ok) {
-                    if (path == QPainterPath())
+                    if (path.isEmpty())
                         path.addRect(rect);
                     if (itemCollidesWithPath(item, xinv.map(path), mode)) {
                         items << item;
@@ -1429,7 +1481,8 @@ QList<QGraphicsItem *> QGraphicsScenePrivate::items_helper(const QPolygonF &poly
 {
     QList<QGraphicsItem *> items;
 
-    QRectF polyRect = _q_adjustedRect(polygon.boundingRect());
+    QRectF polyRect(polygon.boundingRect());
+     _q_adjustRect(&polyRect);
     QPainterPath path;
 
     // The index returns a rough estimate of what items are inside the rect.
@@ -1442,7 +1495,7 @@ QList<QGraphicsItem *> QGraphicsScenePrivate::items_helper(const QPolygonF &poly
         // ### _q_adjustedRect is only needed because QRectF::intersects,
         // QRectF::contains and QTransform::map() and friends don't work with
         // flat rectangles.
-        QRectF br = _q_adjustedRect(item->boundingRect());
+        const QRectF br(adjustedItemBoundingRect(item));
         if (mode >= Qt::ContainsItemBoundingRect) {
             // Polygon contains/intersects item's bounding rect
             if (path == QPainterPath())
@@ -1487,21 +1540,47 @@ QList<QGraphicsItem *> QGraphicsScenePrivate::items_helper(const QPainterPath &p
                                                            Qt::SortOrder order) const
 {
     QList<QGraphicsItem *> items;
+    QRectF pathRect(path.controlPointRect());
+    _q_adjustRect(&pathRect);
+
     // The index returns a rough estimate of what items are inside the rect.
     // Refine it by iterating through all returned items.
-    foreach (QGraphicsItem *item, estimateItemsInRect(_q_adjustedRect(path.controlPointRect()))) {
+    foreach (QGraphicsItem *item, estimateItemsInRect(pathRect)) {
         // Find the item's scene transform in a clever way.
         QTransform x = item->sceneTransform();
-        bool ok;
-        QTransform xinv = x.inverted(&ok);
-        if (ok) {
-            QPainterPath mappedPath = xinv.map(path);
-            if (itemCollidesWithPath(item, mappedPath, mode)) {
+        bool keep = false;
+
+        // ### _q_adjustedRect is only needed because QRectF::intersects,
+        // QRectF::contains and QTransform::map() and friends don't work with
+        // flat rectangles.
+        const QRectF br(adjustedItemBoundingRect(item));
+        if (mode >= Qt::ContainsItemBoundingRect) {
+            // Path contains/intersects item's bounding rect
+            if ((mode == Qt::IntersectsItemBoundingRect && path.intersects(x.mapRect(br)))
+                || (mode == Qt::ContainsItemBoundingRect && path.contains(x.mapRect(br)))) {
                 items << item;
-                if (item->flags() & QGraphicsItem::ItemClipsChildrenToShape)
-                    childItems_helper(&items, item, mappedPath, mode);
+                keep = true;
+            }
+        } else {
+            // Path contains/intersects item's shape
+            if (QRectF_intersects(pathRect, x.mapRect(br))) {
+                bool ok;
+                QTransform xinv = x.inverted(&ok);
+                if (ok) {
+                    if (itemCollidesWithPath(item, xinv.map(path), mode)) {
+                        items << item;
+                        keep = true;
+                    }
+                }
             }
         }
+
+        if (keep && (item->flags() & QGraphicsItem::ItemClipsChildrenToShape)) {
+            bool ok;
+            QTransform xinv = x.inverted(&ok);
+            if (ok)
+                childItems_helper(&items, item, xinv.map(path), mode);
+        }
     }
 
     if (order != Qt::SortOrder(-1))
@@ -1511,13 +1590,13 @@ QList<QGraphicsItem *> QGraphicsScenePrivate::items_helper(const QPainterPath &p
 
 void QGraphicsScenePrivate::childItems_helper(QList<QGraphicsItem *> *items,
                                               const QGraphicsItem *parent,
-                                              const QRectF &rect,
-                                              Qt::ItemSelectionMode mode) const
+                                              const QPointF &pos) const
 {
-    QPainterPath path;
     bool parentClip = (parent->flags() & QGraphicsItem::ItemClipsChildrenToShape);
-    QRectF r = !parentClip ? _q_adjustedRect(rect) : _q_adjustedRect(rect).intersected(_q_adjustedRect(parent->boundingRect()));
-    if (r.isEmpty())
+    if (parentClip && parent->d_ptr->isClippedAway())
+        return;
+    // ### is this needed?
+    if (parentClip && !parent->boundingRect().contains(pos))
         return;
 
     QList<QGraphicsItem *> &children = parent->d_ptr->children;
@@ -1527,31 +1606,73 @@ void QGraphicsScenePrivate::childItems_helper(QList<QGraphicsItem *> *items,
             continue;
 
         // Skip invisible items and all their children.
-        if (!item->d_ptr->visible || qFuzzyCompare(item->effectiveOpacity(), qreal(0.0)))
+        if (item->d_ptr->isInvisible())
             continue;
 
-        // ### _q_adjustedRect is only needed because QRectF::intersects,
-        // QRectF::contains and QTransform::map() and friends don't work with
-        // flat rectangles.
-        QRectF br = _q_adjustedRect(item->boundingRect());
-        QRectF mbr = item->mapRectToParent(br);
         bool keep = false;
-        if (mode >= Qt::ContainsItemBoundingRect) {
-            // Rect intersects/contains item's bounding rect
-            if ((mode == Qt::IntersectsItemBoundingRect && QRectF_intersects(rect, mbr))
-                || (mode == Qt::ContainsItemBoundingRect && rect != mbr && rect.contains(br))) {
+        if (!item->d_ptr->isClippedAway()) {
+            if (item->contains(item->mapFromParent(pos))) {
                 items->append(item);
                 keep = true;
             }
-        } else {
-            // Rect intersects/contains item's shape
-            if (QRectF_intersects(rect, mbr)) {
-                if (path == QPainterPath())
-                    path.addRect(rect);
-                if (itemCollidesWithPath(item, item->mapFromParent(path), mode)) {
+        }
+
+        if ((keep || !(item->flags() & QGraphicsItem::ItemClipsChildrenToShape)) && !item->d_ptr->children.isEmpty())
+            // Recurse into children.
+            childItems_helper(items, item, item->mapFromParent(pos));
+    }
+}
+
+
+void QGraphicsScenePrivate::childItems_helper(QList<QGraphicsItem *> *items,
+                                              const QGraphicsItem *parent,
+                                              const QRectF &rect,
+                                              Qt::ItemSelectionMode mode) const
+{
+    bool parentClip = (parent->flags() & QGraphicsItem::ItemClipsChildrenToShape);
+    if (parentClip && parent->d_ptr->isClippedAway())
+        return;
+    QRectF adjustedRect(rect);
+    _q_adjustRect(&adjustedRect);
+    QRectF r = !parentClip ? adjustedRect : adjustedRect.intersected(adjustedItemBoundingRect(parent));
+    if (r.isEmpty())
+        return;
+
+    QPainterPath path;
+    QList<QGraphicsItem *> &children = parent->d_ptr->children;
+    for (int i = 0; i < children.size(); ++i) {
+        QGraphicsItem *item = children.at(i);
+        if (item->d_ptr->hasTransform && !item->transform().isInvertible())
+            continue;
+
+        // Skip invisible items and all their children.
+        if (item->d_ptr->isInvisible())
+            continue;
+
+        bool keep = false;
+        if (!item->d_ptr->isClippedAway()) {
+            // ### _q_adjustedRect is only needed because QRectF::intersects,
+            // QRectF::contains and QTransform::map() and friends don't work with
+            // flat rectangles.
+            const QRectF br(adjustedItemBoundingRect(item));
+            QRectF mbr = item->mapRectToParent(br);
+            if (mode >= Qt::ContainsItemBoundingRect) {
+                // Rect intersects/contains item's bounding rect
+                if ((mode == Qt::IntersectsItemBoundingRect && QRectF_intersects(rect, mbr))
+                    || (mode == Qt::ContainsItemBoundingRect && rect != mbr && rect.contains(br))) {
                     items->append(item);
                     keep = true;
                 }
+            } else {
+                // Rect intersects/contains item's shape
+                if (QRectF_intersects(rect, mbr)) {
+                    if (path == QPainterPath())
+                        path.addRect(rect);
+                    if (itemCollidesWithPath(item, item->mapFromParent(path), mode)) {
+                        items->append(item);
+                        keep = true;
+                    }
+                }
             }
         }
 
@@ -1568,18 +1689,22 @@ void QGraphicsScenePrivate::childItems_helper(QList<QGraphicsItem *> *items,
     }
 }
 
+
 void QGraphicsScenePrivate::childItems_helper(QList<QGraphicsItem *> *items,
                                               const QGraphicsItem *parent,
                                               const QPolygonF &polygon,
                                               Qt::ItemSelectionMode mode) const
 {
-    QPainterPath path;
     bool parentClip = (parent->flags() & QGraphicsItem::ItemClipsChildrenToShape);
-    QRectF polyRect = _q_adjustedRect(polygon.boundingRect());
-    QRectF r = !parentClip ? polyRect : polyRect.intersected(_q_adjustedRect(parent->boundingRect()));
+    if (parentClip && parent->d_ptr->isClippedAway())
+        return;
+    QRectF polyRect(polygon.boundingRect());
+    _q_adjustRect(&polyRect);
+    QRectF r = !parentClip ? polyRect : polyRect.intersected(adjustedItemBoundingRect(parent));
     if (r.isEmpty())
         return;
 
+    QPainterPath path;
     QList<QGraphicsItem *> &children = parent->d_ptr->children;
     for (int i = 0; i < children.size(); ++i) {
         QGraphicsItem *item = children.at(i);
@@ -1587,32 +1712,34 @@ void QGraphicsScenePrivate::childItems_helper(QList<QGraphicsItem *> *items,
             continue;
 
         // Skip invisible items.
-        if (!item->d_ptr->visible || qFuzzyCompare(item->effectiveOpacity() + 1, qreal(1.0)))
+        if (item->d_ptr->isInvisible())
             continue;
 
-        // ### _q_adjustedRect is only needed because QRectF::intersects,
-        // QRectF::contains and QTransform::map() and friends don't work with
-        // flat rectangles.
-        QRectF br = _q_adjustedRect(item->boundingRect());
         bool keep = false;
-        if (mode >= Qt::ContainsItemBoundingRect) {
-            // Polygon contains/intersects item's bounding rect
-            if (path == QPainterPath())
-                path.addPolygon(polygon);
-            if ((mode == Qt::IntersectsItemBoundingRect && path.intersects(item->mapRectToParent(br)))
-                || (mode == Qt::ContainsItemBoundingRect && path.contains(item->mapRectToParent(br)))) {
-                items->append(item);
-                keep = true;
-            }
-        } else {
-            // Polygon contains/intersects item's shape
-            if (QRectF_intersects(polyRect, item->mapRectToParent(br))) {
+        if (!item->d_ptr->isClippedAway()) {
+            // ### _q_adjustedRect is only needed because QRectF::intersects,
+            // QRectF::contains and QTransform::map() and friends don't work with
+            // flat rectangles.
+            const QRectF br(adjustedItemBoundingRect(item));
+            if (mode >= Qt::ContainsItemBoundingRect) {
+                // Polygon contains/intersects item's bounding rect
                 if (path == QPainterPath())
                     path.addPolygon(polygon);
-                if (itemCollidesWithPath(item, item->mapFromParent(path), mode)) {
+                if ((mode == Qt::IntersectsItemBoundingRect && path.intersects(item->mapRectToParent(br)))
+                    || (mode == Qt::ContainsItemBoundingRect && path.contains(item->mapRectToParent(br)))) {
                     items->append(item);
                     keep = true;
                 }
+            } else {
+                // Polygon contains/intersects item's shape
+                if (QRectF_intersects(polyRect, item->mapRectToParent(br))) {
+                    if (path == QPainterPath())
+                        path.addPolygon(polygon);
+                    if (itemCollidesWithPath(item, item->mapFromParent(path), mode)) {
+                        items->append(item);
+                        keep = true;
+                    }
+                }
             }
         }
 
@@ -1629,30 +1756,52 @@ void QGraphicsScenePrivate::childItems_helper(QList<QGraphicsItem *> *items,
                                               Qt::ItemSelectionMode mode) const
 {
     bool parentClip = (parent->flags() & QGraphicsItem::ItemClipsChildrenToShape);
-    QPainterPath intersectedPath = !parentClip ? path : path.intersected(parent->shape());
-    if (intersectedPath.isEmpty())
+    if (parentClip && parent->d_ptr->isClippedAway())
+        return;
+    QRectF pathRect(path.boundingRect());
+    _q_adjustRect(&pathRect);
+    QRectF r = !parentClip ? pathRect : pathRect.intersected(adjustedItemBoundingRect(parent));
+    if (r.isEmpty())
         return;
 
     QList<QGraphicsItem *> &children = parent->d_ptr->children;
     for (int i = 0; i < children.size(); ++i) {
         QGraphicsItem *item = children.at(i);
+        if (item->d_ptr->hasTransform && !item->transform().isInvertible())
+            continue;
 
         // Skip invisible items.
-        if (!item->d_ptr->visible || qFuzzyCompare(item->effectiveOpacity(), qreal(0.0)))
+        if (item->d_ptr->isInvisible())
             continue;
 
-        QTransform x = item->sceneTransform();
-
-        bool ok;
-        QTransform xinv = x.inverted(&ok);
-        if (ok) {
-            QPainterPath mappedPath = xinv.map(path);
-            if (itemCollidesWithPath(item, mappedPath, mode)) {
-                items->append(item);
-                if (!item->d_ptr->children.isEmpty())
-                    childItems_helper(items, item, mappedPath, mode);
+        bool keep = false;
+        if (!item->d_ptr->isClippedAway()) {
+            // ### _q_adjustedRect is only needed because QRectF::intersects,
+            // QRectF::contains and QTransform::map() and friends don't work with
+            // flat rectangles.
+            const QRectF br(adjustedItemBoundingRect(item));
+            if (mode >= Qt::ContainsItemBoundingRect) {
+                // Polygon contains/intersects item's bounding rect
+                if ((mode == Qt::IntersectsItemBoundingRect && path.intersects(item->mapRectToParent(br)))
+                    || (mode == Qt::ContainsItemBoundingRect && path.contains(item->mapRectToParent(br)))) {
+                    items->append(item);
+                    keep = true;
+                }
+            } else {
+                // Path contains/intersects item's shape
+                if (QRectF_intersects(pathRect, item->mapRectToParent(br))) {
+                    if (itemCollidesWithPath(item, item->mapFromParent(path), mode)) {
+                        items->append(item);
+                        keep = true;
+                    }
+                }
             }
         }
+
+        if ((keep || !(item->flags() & QGraphicsItem::ItemClipsChildrenToShape)) && !item->d_ptr->children.isEmpty()) {
+            // Recurse into children that clip children.
+            childItems_helper(items, item, item->mapFromParent(path), mode);
+        }
     }
 }
 
@@ -2326,17 +2475,8 @@ QList<QGraphicsItem *> QGraphicsScene::items() const
 */
 QList<QGraphicsItem *> QGraphicsScene::items(const QPointF &pos) const
 {
-    QList<QGraphicsItem *> itemsAtPoint;
-
-    // Find all items within a 1x1 rect area starting at pos. This can be
-    // inefficient for scenes that use small coordinates (like unity
-    // coordinates), or for detailed graphs. ### The index should support
-    // fetching items at a pos to avoid this limitation.
-    foreach (QGraphicsItem *item, items(QRectF(pos, QSizeF(1, 1)), Qt::IntersectsItemBoundingRect)) {
-        if (item->contains(item->mapFromScene(pos)))
-            itemsAtPoint << item;
-    }
-    return itemsAtPoint;
+    Q_D(const QGraphicsScene);
+    return d->items_helper(pos);
 }
 
 
@@ -2723,8 +2863,9 @@ void QGraphicsScene::addItem(QGraphicsItem *item)
 
     // Notify the item that its scene is changing, and allow the item to
     // react.
-    QGraphicsScene *targetScene = qVariantValue<QGraphicsScene *>(item->itemChange(QGraphicsItem::ItemSceneChange,
-                                                                                   qVariantFromValue<QGraphicsScene *>(this)));
+    const QVariant newSceneVariant(item->itemChange(QGraphicsItem::ItemSceneChange,
+                                                    qVariantFromValue<QGraphicsScene *>(this)));
+    QGraphicsScene *targetScene = qVariantValue<QGraphicsScene *>(newSceneVariant);
     if (targetScene != this) {
         if (targetScene && item->scene() != targetScene)
             targetScene->addItem(item);
@@ -2818,7 +2959,7 @@ void QGraphicsScene::addItem(QGraphicsItem *item)
         emit selectionChanged();
 
     // Deliver post-change notification
-    item->itemChange(QGraphicsItem::ItemSceneHasChanged, qVariantFromValue<QGraphicsScene *>(this));
+    item->itemChange(QGraphicsItem::ItemSceneHasChanged, newSceneVariant);
 }
 
 /*!
@@ -3082,8 +3223,9 @@ void QGraphicsScene::removeItem(QGraphicsItem *item)
 
     // Notify the item that it's scene is changing to 0, allowing the item to
     // react.
-    QGraphicsScene *targetScene = qVariantValue<QGraphicsScene *>(item->itemChange(QGraphicsItem::ItemSceneChange,
-                                                                                   qVariantFromValue<QGraphicsScene *>(0)));
+    const QVariant newSceneVariant(item->itemChange(QGraphicsItem::ItemSceneChange,
+                                                    qVariantFromValue<QGraphicsScene *>(0)));
+    QGraphicsScene *targetScene = qVariantValue<QGraphicsScene *>(newSceneVariant);
     if (targetScene != 0 && targetScene != this) {
         targetScene->addItem(item);
         return;
@@ -3154,6 +3296,16 @@ void QGraphicsScene::removeItem(QGraphicsItem *item)
     d->unpolishedItems.removeAll(item);
     d->dirtyItems.removeAll(item);
 
+    //We remove all references of item from the sceneEventFilter arrays
+    QMultiMap<QGraphicsItem*, QGraphicsItem*>::iterator iterator = d->sceneEventFilters.begin();
+    while (iterator != d->sceneEventFilters.end()) {
+        if (iterator.value() == item || iterator.key() == item)
+            iterator = d->sceneEventFilters.erase(iterator);
+        else
+            ++iterator;
+    }
+
+
     //Ensure dirty flag have the correct default value so the next time it will be added it will receive updates
     item->d_func()->dirty = 0;
     item->d_func()->dirtyChildren = 0;
@@ -3181,7 +3333,7 @@ void QGraphicsScene::removeItem(QGraphicsItem *item)
         emit selectionChanged();
 
     // Deliver post-change notification
-    item->itemChange(QGraphicsItem::ItemSceneHasChanged, qVariantFromValue<QGraphicsScene *>(0));
+    item->itemChange(QGraphicsItem::ItemSceneHasChanged, newSceneVariant);
 }
 
 /*!
@@ -3455,7 +3607,7 @@ QVariant QGraphicsScene::inputMethodQuery(Qt::InputMethodQuery query) const
 void QGraphicsScene::update(const QRectF &rect)
 {
     Q_D(QGraphicsScene);
-    if (d->updateAll)
+    if (d->updateAll || (rect.isEmpty() && !rect.isNull()))
         return;
 
     // Check if anyone's connected; if not, we can send updates directly to
@@ -4564,7 +4716,9 @@ void QGraphicsScenePrivate::drawItemHelper(QGraphicsItem *item, QPainter *painte
 
     // Item's (local) bounding rect
     QRectF brect = item->boundingRect();
-    if (_q_adjustedRect(brect).isEmpty())
+    QRectF adjustedBrect(brect);
+    _q_adjustRect(&adjustedBrect);
+    if (adjustedBrect.isEmpty())
         return;
 
     // Fetch the off-screen transparent buffer and exposed area info.
@@ -4595,16 +4749,17 @@ void QGraphicsScenePrivate::drawItemHelper(QGraphicsItem *item, QPainter *painte
     if (cacheMode == QGraphicsItem::ItemCoordinateCache) {
         QSize pixmapSize;
         bool fixedCacheSize = false;
+        QRectF brectAligned = brect.toAlignedRect();
         if ((fixedCacheSize = itemCache->fixedSize.isValid())) {
             pixmapSize = itemCache->fixedSize;
         } else {
-            pixmapSize = brect.toAlignedRect().size();
+            pixmapSize = brectAligned.size().toSize();
         }
 
         // Create or recreate the pixmap.
         int adjust = itemCache->fixedSize.isValid() ? 0 : 2;
         QSize adjustSize(adjust*2, adjust*2);
-        QRectF br = brect.adjusted(-adjust, -adjust, adjust, adjust);
+        QRectF br = brectAligned.adjusted(-adjust, -adjust, adjust, adjust);
         if (pix.isNull() || (!fixedCacheSize && (pixmapSize + adjustSize) != pix.size())) {
             pix = QPixmap(pixmapSize + adjustSize);
             itemCache->exposed.clear();
@@ -4614,9 +4769,11 @@ void QGraphicsScenePrivate::drawItemHelper(QGraphicsItem *item, QPainter *painte
         // Redraw any newly exposed areas.
         if (itemCache->allExposed || !itemCache->exposed.isEmpty()) {
             // Fit the item's bounding rect into the pixmap's coordinates.
-            const QPointF scale(pixmapSize.width() / brect.width(), pixmapSize.height() / brect.height());
             QTransform itemToPixmap;
-            itemToPixmap.scale(scale.x(), scale.y());
+            if (fixedCacheSize) {
+                const QPointF scale(pixmapSize.width() / brect.width(), pixmapSize.height() / brect.height());
+                itemToPixmap.scale(scale.x(), scale.y());
+            }
             itemToPixmap.translate(-br.x(), -br.y());
 
             // Generate the item's exposedRect and map its list of expose
@@ -4769,8 +4926,9 @@ void QGraphicsScenePrivate::drawItemHelper(QGraphicsItem *item, QPainter *painte
         if (itemCache->allExposed || !itemCache->exposed.isEmpty() || !scrollExposure.isEmpty()) {
             // Construct an item-to-pixmap transform.
             QPointF p = deviceRect.topLeft();
-            QTransform itemToPixmap = QTransform::fromTranslate(-p.x(), -p.y());
-            itemToPixmap = painter->worldTransform() * itemToPixmap;
+            QTransform itemToPixmap = painter->worldTransform();
+            if (!p.isNull())
+                itemToPixmap *= QTransform::fromTranslate(-p.x(), -p.y());
 
             // Map the item's logical expose to pixmap coordinates.
             QRegion pixmapExposed = scrollExposure;
@@ -5104,9 +5262,12 @@ void QGraphicsScene::itemUpdated(QGraphicsItem *item, const QRectF &rect)
             update(item->sceneBoundingRect());
         } else {
             // ### Remove _q_adjustedRects().
-            QRectF boundingRect = _q_adjustedRect(item->boundingRect());
-            if (!rect.isNull())
-                boundingRect &= _q_adjustedRect(rect);
+            QRectF boundingRect(adjustedItemBoundingRect(item));
+            if (!rect.isNull()) {
+                QRectF adjustedRect(rect);
+                _q_adjustRect(&adjustedRect);
+                boundingRect &= adjustedRect;
+            }
 
             // Update each view directly.
             for (int i = 0; i < d->views.size(); ++i)
@@ -5118,6 +5279,9 @@ void QGraphicsScene::itemUpdated(QGraphicsItem *item, const QRectF &rect)
         d->resetDirtyItemsLater();
     }
 
+    if (!item->isVisible())
+        return; // Hiding an item won't effect the largestUntransformableItem/sceneRect.
+
     // Update d->largestUntransformableItem by mapping this item's bounding
     // rect back to the topmost untransformable item's untransformed
     // coordinate system (which sort of equals the 1:1 coordinate system of an
@@ -5133,7 +5297,9 @@ void QGraphicsScene::itemUpdated(QGraphicsItem *item, const QRectF &rect)
     // defined scene rect.
     if (!d->hasSceneRect) {
         QRectF oldGrowingItemsBoundingRect = d->growingItemsBoundingRect;
-        d->growingItemsBoundingRect |= _q_adjustedRect(item->sceneBoundingRect());
+        QRectF adjustedItemSceneBoundingRect(item->sceneBoundingRect());
+        _q_adjustRect(&adjustedItemSceneBoundingRect);
+        d->growingItemsBoundingRect |= adjustedItemSceneBoundingRect;
         if (d->growingItemsBoundingRect != oldGrowingItemsBoundingRect)
             emit sceneRectChanged(d->growingItemsBoundingRect);
     }
diff --git a/src/gui/graphicsview/qgraphicsscene_p.h b/src/gui/graphicsview/qgraphicsscene_p.h
index 9c165d1..befbbd8 100644
--- a/src/gui/graphicsview/qgraphicsscene_p.h
+++ b/src/gui/graphicsview/qgraphicsscene_p.h
@@ -197,6 +197,7 @@ public:
     void mousePressEventHandler(QGraphicsSceneMouseEvent *mouseEvent);
     QGraphicsWidget *windowForItem(const QGraphicsItem *item) const;
 
+    QList<QGraphicsItem *> items_helper(const QPointF &pos) const;
     QList<QGraphicsItem *> items_helper(const QRectF &rect,
                                         Qt::ItemSelectionMode mode,
                                         Qt::SortOrder order) const;
@@ -208,6 +209,9 @@ public:
                                         Qt::SortOrder order) const;
     void childItems_helper(QList<QGraphicsItem *> *items,
                            const QGraphicsItem *parent,
+                           const QPointF &pos) const;
+    void childItems_helper(QList<QGraphicsItem *> *items,
+                           const QGraphicsItem *parent,
                            const QRectF &rect,
                            Qt::ItemSelectionMode mode) const;
     void childItems_helper(QList<QGraphicsItem *> *items,
diff --git a/src/gui/graphicsview/qgraphicssceneevent.cpp b/src/gui/graphicsview/qgraphicssceneevent.cpp
index 57c79db..b819c2c 100644
--- a/src/gui/graphicsview/qgraphicssceneevent.cpp
+++ b/src/gui/graphicsview/qgraphicssceneevent.cpp
@@ -133,7 +133,7 @@
 
     A QContextMenuEvent received by a QGraphicsView is translated
     into a QGraphicsSceneContextMenuEvent. The
-    QWheelEvent::globalPos() is translated into item, scene, and
+    QContextMenuEvent::globalPos() is translated into item, scene, and
     screen coordinates (pos(), scenePos(), and screenPos()).
 
     \sa QGraphicsSceneMouseEvent, QGraphicsSceneWheelEvent,
diff --git a/src/gui/graphicsview/qgraphicsview.cpp b/src/gui/graphicsview/qgraphicsview.cpp
index 15c0e25..05e4907 100644
--- a/src/gui/graphicsview/qgraphicsview.cpp
+++ b/src/gui/graphicsview/qgraphicsview.cpp
@@ -790,6 +790,19 @@ QRegion QGraphicsViewPrivate::mapToViewRegion(const QGraphicsItem *item, const Q
     return item->boundingRegion(itv) & itv.mapRect(rect).toAlignedRect();
 }
 
+// QRectF::intersects() returns false always if either the source or target
+// rectangle's width or height are 0. This works around that problem.
+static inline QRectF adjustedItemBoundingRect(const QGraphicsItem *item)
+{
+    Q_ASSERT(item);
+    QRectF boundingRect(item->boundingRect());
+    if (!boundingRect.width())
+        boundingRect.adjust(-0.00001, 0, 0.00001, 0);
+    if (!boundingRect.height())
+        boundingRect.adjust(0, -0.00001, 0, 0.00001);
+    return boundingRect;
+}
+
 /*!
     \internal
 */
@@ -801,38 +814,37 @@ void QGraphicsViewPrivate::itemUpdated(QGraphicsItem *item, const QRectF &rect)
         updateLater();
 
     QRectF updateRect = rect;
-    if (item->isClipped()) {
+    if ((item->d_ptr->flags & QGraphicsItem::ItemClipsChildrenToShape) || item->d_ptr->children.isEmpty()) {
+        updateRect &= adjustedItemBoundingRect(item);
+        if (updateRect.isEmpty())
+            return;
+    }
+
+    QGraphicsItem *clipItem = item;
+    if (item->d_ptr->ancestorFlags & QGraphicsItemPrivate::AncestorClipsChildren) {
         // Minimize unnecessary redraw.
-        QGraphicsItem *p = item;
-        while ((p = p->d_ptr->parent)) {
-            if (p->flags() & QGraphicsItem::ItemClipsChildrenToShape) {
-                updateRect &= p->itemTransform(item).mapRect(p->boundingRect());
-                if (updateRect.isNull())
+        QGraphicsItem *parent = item;
+        while ((parent = parent->d_ptr->parent)) {
+            if (parent->d_ptr->flags & QGraphicsItem::ItemClipsChildrenToShape) {
+                // Map update rect to the current parent and itersect with its bounding rect.
+                updateRect = clipItem->itemTransform(parent).mapRect(updateRect)
+                             & adjustedItemBoundingRect(parent);
+                if (updateRect.isEmpty())
                     return;
+                clipItem = parent;
             }
 
-            if (!(p->d_ptr->ancestorFlags & QGraphicsItemPrivate::AncestorClipsChildren))
+            if (!(parent->d_ptr->ancestorFlags & QGraphicsItemPrivate::AncestorClipsChildren))
                 break;
         }
-
-        if (updateRect.isNull())
-            return;
     }
 
-    // Map the rect to view coordinates.
-    QRect vr = viewport->rect();
-
-    if (!item->d_ptr->hasBoundingRegionGranularity) {
-        QRect r = mapToViewRect(item, updateRect) & vr;
-        if (r.isNull())
-            return;
-        this->updateRect(r);
-    } else {
-        QRegion r = mapToViewRegion(item, updateRect) & vr;
-        if (r.isEmpty())
-            return;
-        updateRegion(r);
-    }
+    // Map update rect from clipItem coordinates to view coordinates.
+    Q_ASSERT(clipItem);
+    if (!item->d_ptr->hasBoundingRegionGranularity)
+        this->updateRect(mapToViewRect(clipItem, updateRect) & viewport->rect());
+    else
+        updateRegion(mapToViewRegion(clipItem, updateRect) & viewport->rect());
 }
 
 void QGraphicsViewPrivate::updateLater()
@@ -855,16 +867,19 @@ void QGraphicsViewPrivate::_q_updateLaterSlot()
     const QList<QGraphicsItem *> &dirtyItems = scene->d_func()->dirtyItems;
     for (int i = 0; i < dirtyItems.size(); ++i) {
         const QGraphicsItem *item = dirtyItems.at(i);
+        if (item->d_ptr->discardUpdateRequest(/*ignoreClipping=*/false,
+                                              /*ignoreVisibleBit=*/false,
+                                              /*ignoreDirtyBit=*/true)) {
+            continue;
+        }
         QTransform x = item->sceneTransform() * viewTransform;
-        QRect viewRect = x.mapRect(item->boundingRect()).toAlignedRect() & vr;
-        if (!viewRect.isNull())
-            updateRect(viewRect);
+        updateRect(x.mapRect(item->boundingRect()).toAlignedRect() & vr);
     }
 
     dirtyRectCount += dirtyRects.size();
 
     bool noUpdate = !fullUpdatePending && viewportUpdateMode == QGraphicsView::FullViewportUpdate;
-    if ((dirtyRectCount > 0 || !dirtyBoundingRect.isNull()) && !fullUpdatePending && !noUpdate) {
+    if ((dirtyRectCount > 0 || !dirtyBoundingRect.isEmpty()) && !fullUpdatePending && !noUpdate) {
         if (viewportUpdateMode == QGraphicsView::BoundingRectViewportUpdate
             || (viewportUpdateMode == QGraphicsView::SmartViewportUpdate
                 && dirtyRectCount >= QGRAPHICSVIEW_REGION_RECT_THRESHOLD)) {
@@ -921,6 +936,9 @@ void QGraphicsViewPrivate::updateAll()
 
 void QGraphicsViewPrivate::updateRegion(const QRegion &r)
 {
+    if (r.isEmpty())
+        return;
+
     Q_Q(QGraphicsView);
 
     // Rect intersects viewport - update everything?
@@ -969,6 +987,9 @@ void QGraphicsViewPrivate::updateRegion(const QRegion &r)
 
 void QGraphicsViewPrivate::updateRect(const QRect &r)
 {
+    if (r.isEmpty())
+        return;
+
     Q_Q(QGraphicsView);
 
     // Rect intersects viewport - update everything?
@@ -1023,105 +1044,77 @@ void QGraphicsViewPrivate::freeStyleOptionsArray(QStyleOptionGraphicsItem *array
         delete [] array;
 }
 
+extern QPainterPath qt_regionToPath(const QRegion &region);
 
-QList<QGraphicsItem *> QGraphicsViewPrivate::findItems(const QRegion &exposedRegion,
-                                                       const QTransform &worldTransform,
-                                                       bool *allItems) const
+/*!
+    ### Adjustments in findItems: mapToScene(QRect) forces us to adjust the
+    input rectangle by (0, 0, 1, 1), because it uses QRect::bottomRight()
+    (etc) when mapping the rectangle to a polygon (which is _wrong_). In
+    addition, as QGraphicsItem::boundingRect() is defined in logical space,
+    but the default pen for QPainter is cosmetic with a width of 0, QPainter
+    is at risk of painting 1 pixel outside the bounding rect. Therefore we
+    must search for items with an adjustment of (-1, -1, 1, 1).
+*/
+QList<QGraphicsItem *> QGraphicsViewPrivate::findItems(const QRegion &exposedRegion, bool *allItems) const
 {
     Q_Q(const QGraphicsView);
-    QList<QGraphicsItem *> itemList;
-    QSet<QGraphicsItem *> tmp;
-    bool simpleTransform = worldTransform.type() <= QTransform::TxScale;
-
-    extern QPainterPath qt_regionToPath(const QRegion &region);
-    QPainterPath path = qt_regionToPath(exposedRegion);
-    *allItems = path.contains(q->mapFromScene(scene->d_func()->growingItemsBoundingRect).boundingRect());
-    QList<QRectF> exposedRects;
-    QList<QPolygonF> exposedPolys;
-
-    // Transform the exposed viewport rects to scene rects or polygons
-    foreach (const QRect &rect, exposedRegion.rects()) {
-        QPolygonF exposedPoly = q->mapToScene(rect.adjusted(-1, -1, 1, 1));
-        QRectF exposedRect = exposedPoly.boundingRect();
-        if (!simpleTransform)
-            exposedPolys << exposedPoly;
-        exposedRects << exposedRect;
-    }
-
-    // Find which items need to be drawn.
-    if (*allItems) {
+
+    // Step 1) If all items are contained within the expose region, then
+    // return a list of all visible items.
+    const QRectF exposedRegionSceneBounds = q->mapToScene(exposedRegion.boundingRect().adjusted(-1, -1, 2, 2))
+                                            .boundingRect();
+    if (exposedRegionSceneBounds.contains(scene->d_func()->growingItemsBoundingRect)) {
+        Q_ASSERT(allItems);
+        *allItems = true;
+
         // All items are guaranteed within the exposed region, don't bother using the index.
-        foreach (QGraphicsItem *item, scene->items()) {
+        QList<QGraphicsItem *> itemList(scene->items());
+        int i = 0;
+        while (i < itemList.size()) {
+            const QGraphicsItem *item = itemList.at(i);
             // But we only want to include items that are visible
-            if (item->isVisible())
-                itemList << item;
-        }
-    } else if (simpleTransform) {
-        // Simple rect lookups will do.
-        if (exposedRects.size() > 1) {
-            foreach (const QRectF &rect, exposedRects) {
-                foreach (QGraphicsItem *item, scene->d_func()->items_helper(rect, Qt::IntersectsItemBoundingRect, Qt::SortOrder(-1) /* don't sort */)) {
-                    if (!tmp.contains(item)) {
-                        tmp << item;
-                        itemList << item;
-                    }
-                }
-            }
-        } else {
-            itemList += scene->d_func()->items_helper(exposedRects[0], Qt::IntersectsItemBoundingRect, Qt::SortOrder(-1) /* don't sort */);
-        }
-    } else {
-        // Polygon lookup is necessary.
-        if (exposedRects.size() > 1) {
-            foreach (const QPolygonF &poly, exposedPolys) {
-                foreach (QGraphicsItem *item, scene->d_func()->items_helper(poly, Qt::IntersectsItemBoundingRect, Qt::SortOrder(-1) /* don't sort */)) {
-                    if (!tmp.contains(item)) {
-                        tmp << item;
-                        itemList << item;
-                    }
-                }
-            }
-        } else {
-            itemList += scene->d_func()->items_helper(exposedPolys[0], Qt::IntersectsItemBoundingRect, Qt::SortOrder(-1) /* don't sort */);
+            // The following check is basically the same as item->d_ptr->isInvisible(), except
+            // that we don't check whether the item clips children to shape or propagates its
+            // opacity (we loop through all items, so those checks are wrong in this context).
+            if (!item->isVisible() || item->d_ptr->isClippedAway() || item->d_ptr->isFullyTransparent())
+                itemList.removeAt(i);
+            else
+                ++i;
         }
+
+        // Sort the items.
+        QGraphicsScenePrivate::sortItems(&itemList, Qt::DescendingOrder, scene->d_func()->sortCacheEnabled);
+        return itemList;
     }
 
-    // Check for items that ignore inherited transformations, and add them if
-    // necessary.
-    QRectF untr = scene->d_func()->largestUntransformableItem;
-    if (!*allItems && !untr.isNull()) {
-        // Map the largest untransformable item subtree boundingrect from view
-        // to scene coordinates, and use this to expand all exposed rects in
-        // search for untransformable items.
-        QRectF ltri = matrix.inverted().mapRect(untr);
-        ltri.adjust(-untr.width(), -untr.height(), untr.width(), untr.height());
-
-        foreach (const QRect &rect, exposedRegion.rects()) {
-            QRectF exposed = q->mapToScene(rect.adjusted(-1, -1, 1, 1)).boundingRect();
-            exposed.adjust(-ltri.width(), -ltri.height(), ltri.width(), ltri.height());
-
-            foreach (QGraphicsItem *item, scene->d_func()->estimateItemsInRect(exposed)) {
-                if (item->d_ptr->itemIsUntransformable()) {
-                    if (!tmp.contains(item)) {
-                        QPainterPath rectPath;
-                        rectPath.addRect(rect);
-                        QPainterPath path = item->deviceTransform(q->viewportTransform()).inverted().map(rectPath);
-                        if (item->collidesWithPath(path, Qt::IntersectsItemBoundingRect)) {
-                            itemList << item;
-                            tmp << item;
-                        }
-                    }
-                }
-            }
-        }
+    // Step 2) If the expose region is a simple rect and the view is only
+    // translated or scaled, search for items using
+    // QGraphicsScene::items(QRectF).
+    bool simpleRectLookup =  (scene->d_func()->largestUntransformableItem.isNull()
+                              && exposedRegion.numRects() == 1 && matrix.type() <= QTransform::TxScale);
+    if (simpleRectLookup) {
+        return scene->d_func()->items_helper(exposedRegionSceneBounds,
+                                             Qt::IntersectsItemBoundingRect,
+                                             Qt::DescendingOrder);
     }
-    tmp.clear();
 
-    // Sort the items.
-    QGraphicsScenePrivate::sortItems(&itemList, Qt::DescendingOrder,
-                                     scene->d_func()->sortCacheEnabled);
+    // If the region is complex or the view has a complex transform, adjust
+    // the expose region, convert it to a path, and then search for items
+    // using QGraphicsScene::items(QPainterPath);
+    QRegion adjustedRegion;
+    foreach (const QRect &r, exposedRegion.rects())
+        adjustedRegion += r.adjusted(-1, -1, 1, 1);
+
+    const QPainterPath exposedPath(qt_regionToPath(adjustedRegion));
+    if (scene->d_func()->largestUntransformableItem.isNull()) {
+        const QPainterPath exposedScenePath(q->mapToScene(exposedPath));
+        return scene->d_func()->items_helper(exposedScenePath,
+                                             Qt::IntersectsItemBoundingRect,
+                                             Qt::DescendingOrder);
+    }
 
-    return itemList;
+    // NB! Path must be in viewport coordinates.
+    return itemsInArea(exposedPath, Qt::IntersectsItemBoundingRect, Qt::DescendingOrder);
 }
 
 void QGraphicsViewPrivate::generateStyleOptions(const QList<QGraphicsItem *> &itemList,
@@ -2224,7 +2217,8 @@ QList<QGraphicsItem *> QGraphicsView::items() const
     certainly room for improvement.
 */
 QList<QGraphicsItem *> QGraphicsViewPrivate::itemsInArea(const QPainterPath &path,
-                                                         Qt::ItemSelectionMode mode) const
+                                                         Qt::ItemSelectionMode mode,
+                                                         Qt::SortOrder order) const
 {
     Q_Q(const QGraphicsView);
 
@@ -2274,8 +2268,8 @@ QList<QGraphicsItem *> QGraphicsViewPrivate::itemsInArea(const QPainterPath &pat
     }
 
     // ### Insertion sort would be faster.
-    QGraphicsScenePrivate::sortItems(&result, Qt::AscendingOrder,
-                                     scene->d_func()->sortCacheEnabled);
+    if (order != Qt::SortOrder(-1))
+        QGraphicsScenePrivate::sortItems(&result, order, scene->d_func()->sortCacheEnabled);
     return result;
 }
 
@@ -3280,7 +3274,7 @@ void QGraphicsView::mouseMoveEvent(QMouseEvent *event)
             }
 
             // Update old rubberband
-            if (d->viewportUpdateMode != QGraphicsView::NoViewportUpdate && !d->rubberBandRect.isNull()) {
+            if (d->viewportUpdateMode != QGraphicsView::NoViewportUpdate && !d->rubberBandRect.isEmpty()) {
                 if (d->viewportUpdateMode != FullViewportUpdate)
                     viewport()->update(d->rubberBandRegion(viewport(), d->rubberBandRect));
                 else
@@ -3462,7 +3456,7 @@ void QGraphicsView::paintEvent(QPaintEvent *event)
     QPainter painter(viewport());
     QTransform original = painter.worldTransform();
 #ifndef QT_NO_RUBBERBAND
-    if (d->rubberBanding && !d->rubberBandRect.isNull())
+    if (d->rubberBanding && !d->rubberBandRect.isEmpty())
         painter.save();
 #endif
     // Set up render hints
@@ -3481,7 +3475,7 @@ void QGraphicsView::paintEvent(QPaintEvent *event)
 
     // Find all exposed items
     bool allItems = false;
-    QList<QGraphicsItem *> itemList = d->findItems(exposedRegion, viewTransform, &allItems);
+    QList<QGraphicsItem *> itemList = d->findItems(exposedRegion, &allItems);
 
 #ifdef QGRAPHICSVIEW_DEBUG
     int exposedTime = stopWatch.elapsed();
@@ -3557,7 +3551,7 @@ void QGraphicsView::paintEvent(QPaintEvent *event)
 
 #ifndef QT_NO_RUBBERBAND
     // Rubberband
-    if (d->rubberBanding && !d->rubberBandRect.isNull()) {
+    if (d->rubberBanding && !d->rubberBandRect.isEmpty()) {
         painter.restore();
         QStyleOptionRubberBand option;
         option.initFrom(viewport());
@@ -3631,30 +3625,30 @@ void QGraphicsView::scrollContentsBy(int dx, int dy)
     if (isRightToLeft())
         dx = -dx;
 
-    if (d->viewportUpdateMode != QGraphicsView::NoViewportUpdate
-        && d->viewportUpdateMode != QGraphicsView::FullViewportUpdate) {
-        for (int i = 0; i < d->dirtyRects.size(); ++i)
-            d->dirtyRects[i].translate(dx, dy);
-        for (int i = 0; i < d->dirtyRegions.size(); ++i)
-            d->dirtyRegions[i].translate(dx, dy);
-    }
-
+    if (d->viewportUpdateMode != QGraphicsView::NoViewportUpdate) {
+        if (d->viewportUpdateMode != QGraphicsView::FullViewportUpdate) {
+            for (int i = 0; i < d->dirtyRects.size(); ++i)
+                d->dirtyRects[i].translate(dx, dy);
+            for (int i = 0; i < d->dirtyRegions.size(); ++i)
+                d->dirtyRegions[i].translate(dx, dy);
+            if (d->accelerateScrolling) {
 #ifndef QT_NO_RUBBERBAND
-    // Update old rubberband
-    if (d->viewportUpdateMode != QGraphicsView::NoViewportUpdate && !d->rubberBandRect.isNull()) {
-        if (d->viewportUpdateMode != FullViewportUpdate)
-            viewport()->update(d->rubberBandRegion(viewport(), d->rubberBandRect));
-        else
-            viewport()->update();
-    }
+                // Update new and old rubberband regions
+                if (!d->rubberBandRect.isEmpty()) {
+                    QRegion rubberBandRegion(d->rubberBandRegion(viewport(), d->rubberBandRect));
+                    rubberBandRegion += rubberBandRegion.translated(-dx, -dy);
+                    viewport()->update(rubberBandRegion);
+                }
 #endif
-
-    if (d->viewportUpdateMode != QGraphicsView::NoViewportUpdate){
-        if (d->accelerateScrolling && d->viewportUpdateMode != FullViewportUpdate)
-            viewport()->scroll(dx, dy);
-        else
+                viewport()->scroll(dx, dy);
+            } else {
+                viewport()->update();
+            }
+        } else {
             viewport()->update();
+        }
     }
+
     d->updateLastCenterPoint();
 
     if ((d->cacheMode & CacheBackground)
diff --git a/src/gui/graphicsview/qgraphicsview_p.h b/src/gui/graphicsview/qgraphicsview_p.h
index 2109673..a76279e 100644
--- a/src/gui/graphicsview/qgraphicsview_p.h
+++ b/src/gui/graphicsview/qgraphicsview_p.h
@@ -85,7 +85,8 @@ public:
     qint64 verticalScroll() const;
 
     QList<QGraphicsItem *> itemsInArea(const QPainterPath &path,
-                                       Qt::ItemSelectionMode mode = Qt::IntersectsItemShape) const;
+                                       Qt::ItemSelectionMode mode = Qt::IntersectsItemShape,
+                                       Qt::SortOrder = Qt::AscendingOrder) const;
 
     QPointF mousePressItemPoint;
     QPointF mousePressScenePoint;
@@ -172,9 +173,7 @@ public:
     void updateRegion(const QRegion &region);
     bool updateSceneSlotReimplementedChecked;
 
-    QList<QGraphicsItem *> findItems(const QRegion &exposedRegion,
-				     const QTransform &worldTransform,
-                                     bool *allItems) const;
+    QList<QGraphicsItem *> findItems(const QRegion &exposedRegion, bool *allItems) const;
 
     void generateStyleOptions(const QList<QGraphicsItem *> &itemList,
 			      QGraphicsItem **itemArray,
diff --git a/src/gui/graphicsview/qgraphicswidget.cpp b/src/gui/graphicsview/qgraphicswidget.cpp
index 5cc18f9..7f02fb9 100644
--- a/src/gui/graphicsview/qgraphicswidget.cpp
+++ b/src/gui/graphicsview/qgraphicswidget.cpp
@@ -366,32 +366,33 @@ void QGraphicsWidget::resize(const QSizeF &size)
 void QGraphicsWidget::setGeometry(const QRectF &rect)
 {
     QGraphicsWidgetPrivate *wd = QGraphicsWidget::d_func();
-    const QGraphicsLayoutItemPrivate *d = QGraphicsLayoutItem::d_ptr;
-    setAttribute(Qt::WA_Resized);
-    QRectF newGeom = rect;
-    newGeom.setSize(rect.size().expandedTo(effectiveSizeHint(Qt::MinimumSize))
-                               .boundedTo(effectiveSizeHint(Qt::MaximumSize)));
-    if (newGeom == d->geom)
-        return;
-
-    // Update and prepare to change the geometry (remove from index).
-    if (wd->scene) {
-        if (rect.topLeft() != d->geom.topLeft())
-            wd->fullUpdateHelper(true);
-        else
-            update();
-    }
-    prepareGeometryChange();
-
-    // setPos triggers ItemPositionChange, which can adjust position
+    QGraphicsLayoutItemPrivate *d = QGraphicsLayoutItem::d_ptr;
+    QRectF newGeom;
     QPointF oldPos = d->geom.topLeft();
-    wd->inSetGeometry = 1;
-    wd->setPosHelper(newGeom.topLeft(), /* update = */ false);
-    wd->inSetGeometry = 0;
-    newGeom.moveTopLeft(pos());
-
-    if (newGeom == d->geom)
-        return;
+    if (!wd->inSetPos) {
+        setAttribute(Qt::WA_Resized);
+        newGeom = rect;
+        newGeom.setSize(rect.size().expandedTo(effectiveSizeHint(Qt::MinimumSize))
+                                   .boundedTo(effectiveSizeHint(Qt::MaximumSize)));
+        if (newGeom == d->geom)
+            return;
+
+        // setPos triggers ItemPositionChange, which can adjust position
+        wd->inSetGeometry = 1;
+        wd->setPosHelper(newGeom.topLeft());
+        wd->inSetGeometry = 0;
+        newGeom.moveTopLeft(pos());
+
+        if (newGeom == d->geom)
+           return;
+
+         // Update and prepare to change the geometry (remove from index) if the size has changed.
+        if (wd->scene) {
+            if (rect.topLeft() == d->geom.topLeft()) {
+                prepareGeometryChange();
+            }
+        }
+    }
 
     // Update the layout item geometry
     bool moved = oldPos != pos();
@@ -401,6 +402,11 @@ void QGraphicsWidget::setGeometry(const QRectF &rect)
         event.setOldPos(oldPos);
         event.setNewPos(pos());
         QApplication::sendEvent(this, &event);
+        if (wd->inSetPos) {
+            //set the new pos
+            d->geom.moveTopLeft(pos());
+            return;
+        }
     }
     QSizeF oldSize = size();
     QGraphicsLayoutItem::setGeometry(newGeom);
@@ -1016,9 +1022,11 @@ QVariant QGraphicsWidget::itemChange(GraphicsItemChange change, const QVariant &
         break;
     case ItemPositionHasChanged:
         if (!d->inSetGeometry) {
+            d->inSetPos = 1;
             // Ensure setGeometry is called (avoid recursion when setPos is
             // called from within setGeometry).
             setGeometry(QRectF(pos(), size()));
+            d->inSetPos = 0 ;
         }
         break;
     case ItemParentChange: {
@@ -1269,6 +1277,8 @@ bool QGraphicsWidget::event(QEvent *event)
         break;
     case QEvent::Polish:
         polishEvent();
+        d->polished = true;
+        d->updateFont(d->font);
         break;
     case QEvent::WindowActivate:
     case QEvent::WindowDeactivate:
diff --git a/src/gui/graphicsview/qgraphicswidget_p.cpp b/src/gui/graphicsview/qgraphicswidget_p.cpp
index 641409d..789f8da 100644
--- a/src/gui/graphicsview/qgraphicswidget_p.cpp
+++ b/src/gui/graphicsview/qgraphicswidget_p.cpp
@@ -274,6 +274,8 @@ void QGraphicsWidgetPrivate::updateFont(const QFont &font)
         }
     }
 
+    if (!polished)
+        return;
     // Notify change.
     QEvent event(QEvent::FontChange);
     QApplication::sendEvent(q, &event);
diff --git a/src/gui/graphicsview/qgraphicswidget_p.h b/src/gui/graphicsview/qgraphicswidget_p.h
index afa6812..53eaa31 100644
--- a/src/gui/graphicsview/qgraphicswidget_p.h
+++ b/src/gui/graphicsview/qgraphicswidget_p.h
@@ -85,6 +85,8 @@ public:
           inheritedPaletteResolveMask(0),
           inheritedFontResolveMask(0),
           inSetGeometry(0),
+          polished(0),
+          inSetPos(0),
           focusPolicy(Qt::NoFocus),
           focusNext(0),
           focusPrev(0),
@@ -193,6 +195,8 @@ public:
     }
     quint32 attributes : 10;
     quint32 inSetGeometry : 1;
+    quint32 polished: 1;
+    quint32 inSetPos : 1;
 
     // Focus
     Qt::FocusPolicy focusPolicy;