Don't crash when appending a null item

Task-number: QTBUG-16871

3 files changed, 21 insertions, 5 deletions

diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index 52e4d79..f463887 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -7689,11 +7689,13 @@ void QGraphicsObject::updateMicroFocus()
 
 void QGraphicsItemPrivate::children_append(QDeclarativeListProperty<QGraphicsObject> *list, QGraphicsObject *item)
 {
-    QGraphicsObject *graphicsObject = static_cast<QGraphicsObject *>(list->object);
-    if (QGraphicsItemPrivate::get(graphicsObject)->sendParentChangeNotification) {
-        item->setParentItem(graphicsObject);
-    } else {
-        QGraphicsItemPrivate::get(item)->setParentItemHelper(graphicsObject, 0, 0);
+    if (item) {
+        QGraphicsObject *graphicsObject = static_cast<QGraphicsObject *>(list->object);
+        if (QGraphicsItemPrivate::get(graphicsObject)->sendParentChangeNotification) {
+            item->setParentItem(graphicsObject);
+        } else {
+            QGraphicsItemPrivate::get(item)->setParentItemHelper(graphicsObject, 0, 0);
+        }
     }
 }
 
diff --git a/tests/auto/declarative/qdeclarativeitem/data/qtbug_16871.qml b/tests/auto/declarative/qdeclarativeitem/data/qtbug_16871.qml
new file mode 100644
index 0000000..8102df1
--- /dev/null
+++ b/tests/auto/declarative/qdeclarativeitem/data/qtbug_16871.qml
@@ -0,0 +1,5 @@
+import QtQuick 1.0
+
+Item {
+    children: [ 10 ]
+}
diff --git a/tests/auto/declarative/qdeclarativeitem/tst_qdeclarativeitem.cpp b/tests/auto/declarative/qdeclarativeitem/tst_qdeclarativeitem.cpp
index 447b57b..137522d 100644
--- a/tests/auto/declarative/qdeclarativeitem/tst_qdeclarativeitem.cpp
+++ b/tests/auto/declarative/qdeclarativeitem/tst_qdeclarativeitem.cpp
@@ -86,6 +86,7 @@ private slots:
     void implicitSize();
     void testQtQuick11Attributes();
     void testQtQuick11Attributes_data();
+    void qtbug_16871();
 
 private:
     template<typename T>
@@ -994,6 +995,14 @@ void tst_QDeclarativeItem::testQtQuick11Attributes_data()
         << ":1 \"Item.onImplicitHeightChanged\" is not available in QtQuick 1.0.\n";
 }
 
+void tst_QDeclarativeItem::qtbug_16871()
+{
+    QDeclarativeComponent component(&engine, SRCDIR "/data/qtbug_16871.qml");
+    QObject *o = component.create();
+    QVERIFY(o != 0);
+    delete o;
+}
+
 
 template<typename T>
 T *tst_QDeclarativeItem::findItem(QGraphicsObject *parent, const QString &objectName)