Fix crash in QQuickLoader when source component is garbage collected

It may happen that the QQuickLoader is the last entity left in the system
holding a reference to the QQmlComponent *sourceComponent. We have to let the
garbage collector know about that by keeping a persistent value for it.

Task-number: QTBUG-35334
Change-Id: I715864440378fd9dd4f2d5ef8ff2f171c81ed7ef
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/tests/auto/quick/qquickloader/tst_qquickloader.cpp b/tests/auto/quick/qquickloader/tst_qquickloader.cpp
index 50ded4d95a..1e23d689ff 100644
--- a/tests/auto/quick/qquickloader/tst_qquickloader.cpp
+++ b/tests/auto/quick/qquickloader/tst_qquickloader.cpp
@@ -128,6 +128,8 @@ private slots:
     void sizeBound();
     void QTBUG_30183();
 
+    void sourceComponentGarbageCollection();
+
 private:
     QQmlEngine engine;
 };
@@ -1144,6 +1146,26 @@ void tst_QQuickLoader::QTBUG_30183()
     delete loader;
 }
 
+void tst_QQuickLoader::sourceComponentGarbageCollection()
+{
+    QQmlComponent component(&engine, testFileUrl("sourceComponentGarbageCollection.qml"));
+    QScopedPointer<QObject> obj(component.create());
+    QVERIFY(!obj.isNull());
+
+    QMetaObject::invokeMethod(obj.data(), "setSourceComponent");
+    engine.collectGarbage();
+    QCoreApplication::sendPostedEvents(0, QEvent::DeferredDelete);
+
+    QSignalSpy spy(obj.data(), SIGNAL(loaded()));
+
+    obj->setProperty("active", true);
+
+    if (spy.isEmpty())
+        QVERIFY(spy.wait());
+
+    QCOMPARE(spy.count(), 1);
+}
+
 QTEST_MAIN(tst_QQuickLoader)
 
 #include "tst_qquickloader.moc"