3 files changed, 20 insertions, 10 deletions

diff --git a/src/qmlmodels/qqmladaptormodel.cpp b/src/qmlmodels/qqmladaptormodel.cpp
index dc3ea8019e..fe0ab6bcbc 100644
--- a/src/qmlmodels/qqmladaptormodel.cpp
+++ b/src/qmlmodels/qqmladaptormodel.cpp
@@ -962,30 +962,36 @@ QQmlAdaptorModel::~QQmlAdaptorModel()
     accessors->cleanup(*this);
 }
 
-void QQmlAdaptorModel::setModel(const QVariant &variant, QObject *parent)
+void QQmlAdaptorModel::setModel(const QVariant &variant, QObject *)
 {
     accessors->cleanup(*this);
 
     list.setList(variant);
+    modelStrongReference.clear();
 
     if (QObject *object = qvariant_cast<QObject *>(list.list())) {
-        setObject(object, parent);
+        if (QQmlData *ddata = QQmlData::get(object))
+            modelStrongReference = ddata->jsWrapper;
+        setObject(object);
         if (qobject_cast<QAbstractItemModel *>(object))
             accessors = new VDMAbstractItemModelDataType(this);
         else
             accessors = new VDMObjectDelegateDataType;
     } else if (list.type() == QQmlListAccessor::ListProperty) {
-        setObject(static_cast<const QQmlListReference *>(variant.constData())->object(), parent);
+        auto object = static_cast<const QQmlListReference *>(variant.constData())->object();
+        if (QQmlData *ddata = QQmlData::get(object))
+            modelStrongReference = ddata->jsWrapper;
+        setObject(object);
         accessors = new VDMObjectDelegateDataType;
     } else if (list.type() == QQmlListAccessor::ObjectList) {
-        setObject(nullptr, parent);
+        setObject(nullptr);
         accessors = new VDMObjectDelegateDataType;
     } else if (list.type() != QQmlListAccessor::Invalid
             && list.type() != QQmlListAccessor::Instance) { // Null QObject
-        setObject(nullptr, parent);
+        setObject(nullptr);
         accessors = new VDMListDelegateDataType;
     } else {
-        setObject(nullptr, parent);
+        setObject(nullptr);
         accessors = &qt_vdm_null_accessors;
     }
 }
diff --git a/src/qmlmodels/qqmladaptormodel_p.h b/src/qmlmodels/qqmladaptormodel_p.h
index 531e8d9105..8635762bc4 100644
--- a/src/qmlmodels/qqmladaptormodel_p.h
+++ b/src/qmlmodels/qqmladaptormodel_p.h
@@ -70,7 +70,7 @@ class QQmlDelegateModel;
 class QQmlDelegateModelItem;
 class QQmlDelegateModelItemMetaType;
 
-class Q_QMLMODELS_PRIVATE_EXPORT QQmlAdaptorModel : public QQmlStrongJSQObjectReference<QObject>
+class Q_QMLMODELS_PRIVATE_EXPORT QQmlAdaptorModel : public QQmlGuard<QObject>
 {
 public:
     class Accessors
@@ -114,6 +114,10 @@ public:
     const Accessors *accessors;
     QPersistentModelIndex rootIndex;
     QQmlListAccessor list;
+    // we need to ensure that a JS created model does not get gced, but cannot
+    // arbitrarily set the parent  (using QQmlStrongJSQObjectReference)  of QObject based models,
+    // as that causes issues with singletons
+    QV4::PersistentValue modelStrongReference;
 
     QTypeRevision modelItemRevision = QTypeRevision::zero();
 
@@ -121,7 +125,7 @@ public:
     ~QQmlAdaptorModel();
 
     inline QVariant model() const { return list.list(); }
-    void setModel(const QVariant &variant, QObject *parent);
+    void setModel(const QVariant &variant, QObject *parent = nullptr);
     void invalidateModel();
 
     bool isValid() const;
diff --git a/src/qmlmodels/qqmldelegatemodel.cpp b/src/qmlmodels/qqmldelegatemodel.cpp
index bbaad6d878..5ace1809d1 100644
--- a/src/qmlmodels/qqmldelegatemodel.cpp
+++ b/src/qmlmodels/qqmldelegatemodel.cpp
@@ -259,7 +259,7 @@ QQmlDelegateModel::~QQmlDelegateModel()
 {
     Q_D(QQmlDelegateModel);
     d->disconnectFromAbstractItemModel();
-    d->m_adaptorModel.setObject(nullptr, this);
+    d->m_adaptorModel.setObject(nullptr);
 
     for (QQmlDelegateModelItem *cacheItem : qAsConst(d->m_cache)) {
         if (cacheItem->object) {
@@ -443,7 +443,7 @@ void QQmlDelegateModel::setModel(const QVariant &model)
         _q_itemsRemoved(0, d->m_count);
 
     d->disconnectFromAbstractItemModel();
-    d->m_adaptorModel.setModel(model, this);
+    d->m_adaptorModel.setModel(model);
     d->connectToAbstractItemModel();
 
     d->m_adaptorModel.replaceWatchedRoles(QList<QByteArray>(), d->m_watchedRoles);