QQmlIncubator: handle clear inside setinitialState

Fixes: QTBUG-91519
Change-Id: Idfe3116c2e94b8e96300d72e15db0bc78425f517
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
(cherry picked from commit 2cb306c194625626957fcde44bd56473b0436f83)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

2 files changed, 34 insertions, 1 deletions

diff --git a/src/qml/qml/qqmlincubator.cpp b/src/qml/qml/qqmlincubator.cpp
index f7cdbda01c..caf419b778 100644
--- a/src/qml/qml/qqmlincubator.cpp
+++ b/src/qml/qml/qqmlincubator.cpp
@@ -330,7 +330,7 @@ void QQmlIncubatorPrivate::incubate(QQmlInstantiationInterrupt &i)
             ddata->rootObjectInCreation = false;
             if (q) {
                 q->setInitialState(result);
-                if (!creator->requiredProperties().empty()) {
+                if (creator && !creator->requiredProperties().empty()) {
                     const auto& unsetRequiredProperties = creator->requiredProperties();
                     for (const auto& unsetRequiredProperty: unsetRequiredProperties)
                         errors << QQmlComponentPrivate::unsetRequiredPropertyToQQmlError(unsetRequiredProperty);
diff --git a/tests/auto/qml/qqmlincubator/tst_qqmlincubator.cpp b/tests/auto/qml/qqmlincubator/tst_qqmlincubator.cpp
index 549aae8c2b..25adf4f31d 100644
--- a/tests/auto/qml/qqmlincubator/tst_qqmlincubator.cpp
+++ b/tests/auto/qml/qqmlincubator/tst_qqmlincubator.cpp
@@ -71,6 +71,7 @@ private slots:
     void contextDelete();
     void garbageCollection();
     void requiredProperties();
+    void deleteInSetInitialState();
 
 private:
     QQmlIncubationController controller;
@@ -1213,6 +1214,38 @@ void tst_qqmlincubator::requiredProperties()
     }
 }
 
+class DeletingIncubator : public QQmlIncubator
+{
+
+
+    // QQmlIncubator interface
+protected:
+    void statusChanged(Status) override
+    {
+
+    }
+    void setInitialState(QObject *obj) override
+    {
+        delete obj;
+        clear();
+    }
+};
+
+void tst_qqmlincubator::deleteInSetInitialState()
+{
+    QQmlComponent component(&engine, testFileUrl("requiredProperty.qml"));
+    QVERIFY(component.isReady());
+    // forceCompletion immediately after creating an asynchronous object completes it
+    DeletingIncubator incubator;
+    incubator.setInitialProperties({{"requiredProperty", 42}});
+    QVERIFY(incubator.isNull());
+    component.create(incubator);
+    QVERIFY(incubator.isLoading());
+    incubator.forceCompletion(); // no crash
+    QVERIFY(incubator.isNull());
+    QCOMPARE(incubator.object(), nullptr); // object was deleted
+}
+
 QTEST_MAIN(tst_qqmlincubator)
 
 #include "tst_qqmlincubator.moc"