2 files changed, 25 insertions, 1 deletions
diff --git a/src/corelib/itemmodels/qsortfilterproxymodel.cpp b/src/corelib/itemmodels/qsortfilterproxymodel.cpp
index fad980f568..b4ba1a2823 100644
--- a/src/corelib/itemmodels/qsortfilterproxymodel.cpp
+++ b/src/corelib/itemmodels/qsortfilterproxymodel.cpp
@@ -1857,6 +1857,9 @@ void QSortFilterProxyModel::setSourceModel(QAbstractItemModel *sourceModel)
 {
     Q_D(QSortFilterProxyModel);
 
+    if (sourceModel == d->model)
+        return;
+
     beginResetModel();
 
     disconnect(d->model, SIGNAL(dataChanged(QModelIndex,QModelIndex,QVector<int>)),
@@ -1910,6 +1913,7 @@ void QSortFilterProxyModel::setSourceModel(QAbstractItemModel *sourceModel)
     disconnect(d->model, SIGNAL(modelAboutToBeReset()), this, SLOT(_q_sourceAboutToBeReset()));
     disconnect(d->model, SIGNAL(modelReset()), this, SLOT(_q_sourceReset()));
 
+    d->_q_sourceModelDestroyed();
     QAbstractProxyModel::setSourceModel(sourceModel);
 
     connect(d->model, SIGNAL(dataChanged(QModelIndex,QModelIndex,QVector<int>)),
@@ -1963,7 +1967,6 @@ void QSortFilterProxyModel::setSourceModel(QAbstractItemModel *sourceModel)
     connect(d->model, SIGNAL(modelAboutToBeReset()), this, SLOT(_q_sourceAboutToBeReset()));
     connect(d->model, SIGNAL(modelReset()), this, SLOT(_q_sourceReset()));
 
-    d->_q_clearMapping();
     endResetModel();
     if (d->update_source_sort_column() && d->dynamic_sortfilter)
         d->sort();
diff --git a/tests/auto/corelib/itemmodels/qsortfilterproxymodel/tst_qsortfilterproxymodel.cpp b/tests/auto/corelib/itemmodels/qsortfilterproxymodel/tst_qsortfilterproxymodel.cpp
index 8333809c40..dd5394d452 100644
--- a/tests/auto/corelib/itemmodels/qsortfilterproxymodel/tst_qsortfilterproxymodel.cpp
+++ b/tests/auto/corelib/itemmodels/qsortfilterproxymodel/tst_qsortfilterproxymodel.cpp
@@ -152,6 +152,7 @@ private slots:
     void emitLayoutChangedOnlyIfSortingChanged_data();
     void emitLayoutChangedOnlyIfSortingChanged();
 
+    void checkSetNewModel();
 protected:
     void buildHierarchy(const QStringList &data, QAbstractItemModel *model);
     void checkHierarchy(const QStringList &data, const QAbstractItemModel *model);
@@ -4227,6 +4228,10 @@ public:
 
     QModelIndex index(int, int, const QModelIndex& parent = QModelIndex()) const override
     {
+        // QTBUG-44962: Would we always expect the parent to belong to the model
+        qDebug() << parent.model() << this;
+        Q_ASSERT(!parent.isValid() || parent.model() == this);
+
         quintptr parentId = (parent.isValid()) ? parent.internalId() : 0;
         if (parentId >= m_depth)
             return QModelIndex();
@@ -4507,5 +4512,21 @@ void tst_QSortFilterProxyModel::dynamicFilterWithoutSort()
     QCOMPARE(resetSpy.count(), 1);
 }
 
+void tst_QSortFilterProxyModel::checkSetNewModel()
+{
+    QTreeView tv;
+    StepTreeModel model1;
+    model1.setDepth(4);
+    StepTreeModel model2;
+    model2.setDepth(4);
+
+    QSortFilterProxyModel proxy;
+    proxy.setSourceModel(&model1);
+    tv.setModel(&proxy);
+    tv.show();
+    tv.expandAll(); // create persistent indexes
+    proxy.setSourceModel(&model2);
+}
+
 QTEST_MAIN(tst_QSortFilterProxyModel)
 #include "tst_qsortfilterproxymodel.moc"