5 files changed, 37 insertions, 9 deletions

diff --git a/src/qml/qml/qqmlguard_p.h b/src/qml/qml/qqmlguard_p.h
index 808bf4c709..3ac63926a0 100644
--- a/src/qml/qml/qqmlguard_p.h
+++ b/src/qml/qml/qqmlguard_p.h
@@ -106,6 +106,34 @@ protected:
     virtual void objectDestroyed(T *) {}
 };
 
+template <typename T>
+class QQmlStrongJSQObjectReference : public QQmlGuard<T>
+{
+public:
+    void setObject(T *o, QObject *parent) {
+        T *old = this->object();
+        if (o == old)
+            return;
+
+        if (m_jsOwnership && old && old->parent() == parent)
+            QQml_setParent_noEvent(old, nullptr);
+
+        this->QQmlGuard<T>::operator=(o);
+
+        if (o && !o->parent() && !QQmlData::keepAliveDuringGarbageCollection(o)) {
+            m_jsOwnership = true;
+            QQml_setParent_noEvent(o, parent);
+        } else {
+            m_jsOwnership = false;
+        }
+    }
+
+private:
+    using QQmlGuard<T>::setObject;
+    using QQmlGuard<T>::operator=;
+    bool m_jsOwnership = false;
+};
+
 QT_END_NAMESPACE
 
 Q_DECLARE_METATYPE(QQmlGuard<QObject>)
diff --git a/src/qml/types/qqmldelegatemodel.cpp b/src/qml/types/qqmldelegatemodel.cpp
index 1c0da2875c..61cbb8700a 100644
--- a/src/qml/types/qqmldelegatemodel.cpp
+++ b/src/qml/types/qqmldelegatemodel.cpp
@@ -200,8 +200,7 @@ QQmlDelegateModelParts::QQmlDelegateModelParts(QQmlDelegateModel *parent)
 */
 
 QQmlDelegateModelPrivate::QQmlDelegateModelPrivate(QQmlContext *ctxt)
-    : m_delegate(nullptr)
-    , m_cacheMetaType(nullptr)
+    : m_cacheMetaType(nullptr)
     , m_context(ctxt)
     , m_parts(nullptr)
     , m_filterGroup(QStringLiteral("items"))
@@ -263,6 +262,7 @@ QQmlDelegateModel::QQmlDelegateModel(QQmlContext *ctxt, QObject *parent)
 QQmlDelegateModel::~QQmlDelegateModel()
 {
     Q_D(QQmlDelegateModel);
+    d->m_adaptorModel.setObject(nullptr, this);
 
     for (QQmlDelegateModelItem *cacheItem : qAsConst(d->m_cache)) {
         if (cacheItem->object) {
@@ -409,7 +409,7 @@ void QQmlDelegateModel::setDelegate(QQmlComponent *delegate)
         return;
     }
     bool wasValid = d->m_delegate != nullptr;
-    d->m_delegate = delegate;
+    d->m_delegate.setObject(delegate, this);
     d->m_delegateValidated = false;
     if (wasValid && d->m_complete) {
         for (int i = 1; i < d->m_groupCount; ++i) {
diff --git a/src/qml/types/qqmldelegatemodel_p_p.h b/src/qml/types/qqmldelegatemodel_p_p.h
index fc46986e23..3f9dd12243 100644
--- a/src/qml/types/qqmldelegatemodel_p_p.h
+++ b/src/qml/types/qqmldelegatemodel_p_p.h
@@ -305,7 +305,7 @@ public:
 
     QQmlAdaptorModel m_adaptorModel;
     QQmlListCompositor m_compositor;
-    QQmlComponent *m_delegate;
+    QQmlStrongJSQObjectReference<QQmlComponent> m_delegate;
     QQmlDelegateModelItemMetaType *m_cacheMetaType;
     QPointer<QQmlContext> m_context;
     QQmlDelegateModelParts *m_parts;
diff --git a/src/qml/util/qqmladaptormodel.cpp b/src/qml/util/qqmladaptormodel.cpp
index c430074f56..15844017aa 100644
--- a/src/qml/util/qqmladaptormodel.cpp
+++ b/src/qml/util/qqmladaptormodel.cpp
@@ -956,7 +956,7 @@ void QQmlAdaptorModel::setModel(const QVariant &variant, QQmlDelegateModel *vdm,
     list.setList(variant, engine);
 
     if (QObject *object = qvariant_cast<QObject *>(list.list())) {
-        setObject(object);
+        setObject(object, vdm);
         if (QAbstractItemModel *model = qobject_cast<QAbstractItemModel *>(object)) {
             accessors = new VDMAbstractItemModelDataType(this);
 
@@ -978,14 +978,14 @@ void QQmlAdaptorModel::setModel(const QVariant &variant, QQmlDelegateModel *vdm,
             accessors = new VDMObjectDelegateDataType;
         }
     } else if (list.type() == QQmlListAccessor::ListProperty) {
-        setObject(static_cast<const QQmlListReference *>(variant.constData())->object());
+        setObject(static_cast<const QQmlListReference *>(variant.constData())->object(), vdm);
         accessors = new VDMObjectDelegateDataType;
     } else if (list.type() != QQmlListAccessor::Invalid
             && list.type() != QQmlListAccessor::Instance) { // Null QObject
-        setObject(nullptr);
+        setObject(nullptr, vdm);
         accessors = &qt_vdm_list_accessors;
     } else {
-        setObject(nullptr);
+        setObject(nullptr, vdm);
         accessors = &qt_vdm_null_accessors;
     }
 }
diff --git a/src/qml/util/qqmladaptormodel_p.h b/src/qml/util/qqmladaptormodel_p.h
index b706fcb5f2..3b2d180ca7 100644
--- a/src/qml/util/qqmladaptormodel_p.h
+++ b/src/qml/util/qqmladaptormodel_p.h
@@ -68,7 +68,7 @@ class QQmlDelegateModel;
 class QQmlDelegateModelItem;
 class QQmlDelegateModelItemMetaType;
 
-class QQmlAdaptorModel : public QQmlGuard<QObject>
+class QQmlAdaptorModel : public QQmlStrongJSQObjectReference<QObject>
 {
 public:
     class Accessors