Fix a crash when reparenting an item in QGraphicsView.

Before calling addItem we need to invalidate the depth otherwise if
someone call anything relating to sorting when itemChange is called
(because of the scene change for instance) then qt_closestItemFirst
for example can crash because of an invalid state.

Task-number:QTBUG-6932
Reviewed-by:janarve

2 files changed, 37 insertions, 2 deletions

diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index f3c90ca..9852323 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -1130,6 +1130,9 @@ void QGraphicsItemPrivate::setParentItemHelper(QGraphicsItem *newParent, const Q
         }
     }
 
+    // Resolve depth.
+    invalidateDepthRecursively();
+
     if ((parent = newParent)) {
         if (parent->d_func()->scene && parent->d_func()->scene != scene) {
             // Move this item to its new parent's scene
@@ -1180,8 +1183,6 @@ void QGraphicsItemPrivate::setParentItemHelper(QGraphicsItem *newParent, const Q
         }
     }
 
-    // Resolve depth.
-    invalidateDepthRecursively();
     dirtySceneTransform = 1;
 
     // Restore the sub focus chain.
diff --git a/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp b/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp
index 4d9f23f..75fb337 100644
--- a/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp
+++ b/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp
@@ -439,6 +439,7 @@ private slots:
     void QTBUG_7714_fullUpdateDiscardingOpacityUpdate2();
     void QT_2653_fullUpdateDiscardingOpacityUpdate();
     void QT_2649_focusScope();
+    void sortItemsWhileAdding();
 
 private:
     QList<QGraphicsItem *> paintedItems;
@@ -10070,5 +10071,38 @@ void tst_QGraphicsItem::QT_2649_focusScope()
     delete scene;
 }
 
+class MyGraphicsItemWithItemChange : public QGraphicsWidget
+{
+public:
+    MyGraphicsItemWithItemChange(QGraphicsItem *parent = 0) : QGraphicsWidget(parent)
+    {}
+
+    QVariant itemChange(GraphicsItemChange change, const QVariant &value)
+    {
+        if (change == QGraphicsItem::ItemSceneHasChanged) {
+            foreach (QGraphicsView *view, scene()->views()) {
+                //We trigger a sort of unindexed items in the BSP
+                view->sceneRect();
+            }
+        }
+        return QGraphicsWidget::itemChange(change, value);
+    }
+};
+
+void tst_QGraphicsItem::sortItemsWhileAdding()
+{
+    QGraphicsScene scene;
+    QGraphicsView view(&scene);
+    QGraphicsWidget grandGrandParent;
+    grandGrandParent.resize(200, 200);
+    scene.addItem(&grandGrandParent);
+    QGraphicsWidget grandParent;
+    grandParent.resize(200, 200);
+    QGraphicsWidget parent(&grandParent);
+    parent.resize(200, 200);
+    MyGraphicsItemWithItemChange item(&parent);
+    grandParent.setParentItem(&grandGrandParent);
+}
+
 QTEST_MAIN(tst_QGraphicsItem)
 #include "tst_qgraphicsitem.moc"