2 files changed, 61 insertions, 0 deletions

diff --git a/src/gui/graphicsview/qgraphicsscene.cpp b/src/gui/graphicsview/qgraphicsscene.cpp
index ae0abf9..22c3f92 100644
--- a/src/gui/graphicsview/qgraphicsscene.cpp
+++ b/src/gui/graphicsview/qgraphicsscene.cpp
@@ -4889,6 +4889,24 @@ void QGraphicsScenePrivate::markDirty(QGraphicsItem *item, const QRectF &rect, b
     if (updateAll)
         return;
 
+    if (removingItemFromScene && !ignoreOpacity && !item->d_ptr->ignoreOpacity) {
+        // If any of the item's ancestors ignore opacity, it means that the opacity
+        // was set to 0 (and the update request has not yet been processed). That
+        // also means that we have to ignore the opacity for the item itself; otherwise
+        // things like: parent->setOpacity(0); scene->removeItem(child) won't work.
+        // Note that we only do this when removing items from the scene. In all other
+        // cases the ignoreOpacity bit propagates properly in processDirtyItems, but
+        // since the item is removed immediately it won't be processed there.
+        QGraphicsItem *p = item->d_ptr->parent;
+        while (p) {
+            if (p->d_ptr->ignoreOpacity) {
+                item->d_ptr->ignoreOpacity = true;
+                break;
+            }
+            p = p->d_ptr->parent;
+        }
+    }
+
     if (item->d_ptr->discardUpdateRequest(/*ignoreVisibleBit=*/force,
                                           /*ignoreDirtyBit=*/removingItemFromScene || invalidateChildren,
                                           /*ignoreOpacity=*/ignoreOpacity)) {
diff --git a/tests/auto/qgraphicsscene/tst_qgraphicsscene.cpp b/tests/auto/qgraphicsscene/tst_qgraphicsscene.cpp
index a155222..67a41ca 100644
--- a/tests/auto/qgraphicsscene/tst_qgraphicsscene.cpp
+++ b/tests/auto/qgraphicsscene/tst_qgraphicsscene.cpp
@@ -275,6 +275,7 @@ private slots:
     void polishItems2();
     void isActive();
     void siblingIndexAlwaysValid();
+    void removeFullyTransparentItem();
 
     // task specific tests below me
     void task139710_bspTreeCrash();
@@ -4333,6 +4334,48 @@ void tst_QGraphicsScene::siblingIndexAlwaysValid()
 
 }
 
+void tst_QGraphicsScene::removeFullyTransparentItem()
+{
+    QGraphicsScene scene;
+
+    QGraphicsItem *parent = scene.addRect(0, 0, 100, 100);
+    parent->setFlag(QGraphicsItem::ItemHasNoContents);
+
+    QGraphicsItem *child = scene.addRect(0, 0, 100, 100);
+    child->setParentItem(parent);
+
+    CustomView view;
+    view.setScene(&scene);
+    view.show();
+    QTest::qWaitForWindowShown(&view);
+
+    // NB! The parent has the ItemHasNoContents flag set, which means
+    // the parent itself doesn't generate any update requests, only the
+    // child can possibly trigger an update. Also note that the child
+    // is removed before processing events.
+    view.repaints = 0;
+    parent->setOpacity(0);
+    QVERIFY(qFuzzyIsNull(child->effectiveOpacity()));
+    scene.removeItem(child);
+    QVERIFY(!scene.items().contains(child));
+    QTRY_VERIFY(view.repaints > 0);
+
+    // Re-add child. There's nothing new to display (child is still
+    // effectively hidden), so it shouldn't trigger an update.
+    view.repaints = 0;
+    child->setParentItem(parent);
+    QVERIFY(scene.items().contains(child));
+    QVERIFY(qFuzzyIsNull(child->effectiveOpacity()));
+    QApplication::processEvents();
+    QCOMPARE(view.repaints, 0);
+
+    // Nothing is visible on the screen, removing child item shouldn't trigger an update.
+    scene.removeItem(child);
+    QApplication::processEvents();
+    QCOMPARE(view.repaints, 0);
+    delete child;
+}
+
 void tst_QGraphicsScene::taskQTBUG_5904_crashWithDeviceCoordinateCache()
 {
     QGraphicsScene scene;