QGraphicsItem::setOpacity(0.0) does not trigger an update of child items

Forwarding the ignoreOpacity flag to children in QGraphicsItemPrivate::fullUpdateHelper.
This is a complementary fix to task 252913, partly fixed in commit 2e3a5ea44...

Reviewed-by: bnilsen
BT: yes

2 files changed, 51 insertions, 2 deletions

diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index e8ace6575f..7b1967bfd2 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -3721,7 +3721,7 @@ void QGraphicsItemPrivate::fullUpdateHelper(bool childrenOnly, bool maybeDirtyCl
         }
     }
     foreach (QGraphicsItem *child, children)
-        child->d_ptr->fullUpdateHelper(false, maybeDirtyClipPath);
+        child->d_ptr->fullUpdateHelper(false, maybeDirtyClipPath, ignoreOpacity);
     dirtyChildren = 1;
 }
 
diff --git a/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp b/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp
index 34a6ab18d0..30174079d8 100644
--- a/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp
+++ b/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp
@@ -207,6 +207,7 @@ private slots:
     void opacity_data();
     void opacity();
     void opacity2();
+    void opacityZeroUpdates();
     void itemStacksBehindParent();
     void nestedClipping();
     void nestedClippingTransforms();
@@ -5498,7 +5499,7 @@ void tst_QGraphicsItem::itemTransform_unrelated()
     QCOMPARE(stranger1->itemTransform(stranger2).map(QPointF(10, 10)), QPointF(10, 10));
     QCOMPARE(stranger2->itemTransform(stranger1).map(QPointF(10, 10)), QPointF(10, 10));
 }
-        
+
 void tst_QGraphicsItem::opacity_data()
 {
     QTest::addColumn<qreal>("p_opacity");
@@ -5693,6 +5694,54 @@ void tst_QGraphicsItem::opacity2()
     QCOMPARE(grandChild->repaints, 0);
 }
 
+void tst_QGraphicsItem::opacityZeroUpdates()
+{
+    EventTester *parent = new EventTester;
+    EventTester *child = new EventTester(parent);
+
+    child->setPos(10, 10);
+
+    QGraphicsScene scene;
+    scene.addItem(parent);
+
+    class MyGraphicsView : public QGraphicsView
+    { public:
+        int repaints;
+        QRegion paintedRegion;
+        MyGraphicsView(QGraphicsScene *scene) : QGraphicsView(scene), repaints(0) {}
+        void paintEvent(QPaintEvent *e)
+        {
+            ++repaints;
+            paintedRegion += e->region();
+            QGraphicsView::paintEvent(e);
+        }
+        void reset() { repaints = 0; paintedRegion = QRegion(); }
+    };
+
+    MyGraphicsView view(&scene);
+    view.show();
+#ifdef Q_WS_X11
+    qt_x11_wait_for_window_manager(&view);
+#endif
+    QTest::qWait(250);
+
+    view.reset();
+    parent->setOpacity(0.0);
+
+    QTest::qWait(200);
+
+    // transforming items bounding rect to view coordinates
+    const QRect childDeviceBoundingRect = child->deviceTransform(view.viewportTransform())
+                                           .mapRect(child->boundingRect()).toRect();
+    const QRect parentDeviceBoundingRect = parent->deviceTransform(view.viewportTransform())
+                                           .mapRect(parent->boundingRect()).toRect();
+
+    QRegion expectedRegion = parentDeviceBoundingRect.adjusted(-2, -2, 2, 2);
+    expectedRegion += childDeviceBoundingRect.adjusted(-2, -2, 2, 2);
+
+    QCOMPARE(view.paintedRegion, expectedRegion);
+}
+
 void tst_QGraphicsItem::itemStacksBehindParent()
 {
     QGraphicsRectItem *parent1 = new QGraphicsRectItem(QRectF(0, 0, 100, 50));