Fix crash when assigning a null QObject or derived property as a ListView model

Fall through to the null case handler in the event of a QVariant of QObject or
derived type with a null value, rather than asserting in the instance handler.

Task-number: QTBUG-34999

Change-Id: I5eeffbe29a263c57e6157d516b138ddc8e2e7a95
Reviewed-by: Alan Alpert <aalpert@blackberry.com>

2 files changed, 43 insertions, 0 deletions

diff --git a/tests/auto/quick/qquicklistview/data/typedModel.qml b/tests/auto/quick/qquicklistview/data/typedModel.qml
new file mode 100644
index 0000000000..d2b3f7e42f
--- /dev/null
+++ b/tests/auto/quick/qquicklistview/data/typedModel.qml
@@ -0,0 +1,23 @@
+import QtQuick 2.0
+
+ListView {
+    width: 100
+    height: 100
+
+    delegate: Item {
+        width: 100
+        height: 10
+    }
+    model: listModel
+
+    ListModel {
+        id: listModel
+
+        ListElement { label: "a" }
+        ListElement { label: "b" }
+        ListElement { label: "c" }
+        ListElement { label: "d" }
+        ListElement { label: "e" }
+        ListElement { label: "f" }
+    }
+}
diff --git a/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp b/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
index f62151c2d8..6ec7cf8dc1 100644
--- a/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
+++ b/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
@@ -213,6 +213,8 @@ private slots:
     void outsideViewportChangeNotAffectingView();
     void testProxyModelChangedAfterMove();
 
+    void typedModel();
+
 private:
     template <class T> void items(const QUrl &source);
     template <class T> void changed(const QUrl &source);
@@ -6960,6 +6962,24 @@ void tst_QQuickListView::testProxyModelChangedAfterMove()
     delete window;
 }
 
+void tst_QQuickListView::typedModel()
+{
+    QQmlEngine engine;
+    QQmlComponent component(&engine, testFileUrl("typedModel.qml"));
+
+    QScopedPointer<QObject> object(component.create());
+
+    QQuickListView *listview = qobject_cast<QQuickListView *>(object.data());
+    QVERIFY(listview);
+
+    QCOMPARE(listview->count(), 6);
+
+    QQmlListModel *listModel = 0;
+
+    listview->setModel(QVariant::fromValue(listModel));
+    QCOMPARE(listview->count(), 0);
+}
+
 QTEST_MAIN(tst_QQuickListView)
 
 #include "tst_qquicklistview.moc"