QSortProxyModel: Crash when changing model with 2-level proxy and selected items

The index mapping to the base model was being cleared before the persistant
model indices.

Reviewed-by: Olivier
Task-number: QTBUG-6237

2 files changed, 42 insertions, 1 deletions

diff --git a/src/gui/itemviews/qsortfilterproxymodel.cpp b/src/gui/itemviews/qsortfilterproxymodel.cpp
index f1ae3d2..fc82f30 100644
--- a/src/gui/itemviews/qsortfilterproxymodel.cpp
+++ b/src/gui/itemviews/qsortfilterproxymodel.cpp
@@ -1153,6 +1153,8 @@ void QSortFilterProxyModelPrivate::_q_sourceAboutToBeReset()
 {
     Q_Q(QSortFilterProxyModel);
     q->beginResetModel();
+    invalidatePersistentIndexes();
+    clear_mapping();
 }
 
 void QSortFilterProxyModelPrivate::_q_sourceReset()
@@ -1470,6 +1472,8 @@ void QSortFilterProxyModel::setSourceModel(QAbstractItemModel *sourceModel)
 {
     Q_D(QSortFilterProxyModel);
 
+    beginResetModel();
+
     disconnect(d->model, SIGNAL(dataChanged(QModelIndex,QModelIndex)),
                this, SLOT(_q_sourceDataChanged(QModelIndex,QModelIndex)));
 
@@ -1551,7 +1555,7 @@ void QSortFilterProxyModel::setSourceModel(QAbstractItemModel *sourceModel)
     connect(d->model, SIGNAL(modelReset()), this, SLOT(_q_sourceReset()));
 
     d->clear_mapping();
-    reset();
+    endResetModel();
     if (d->update_source_sort_column() && d->dynamic_sortfilter)
         d->sort();
 }
diff --git a/tests/auto/qsortfilterproxymodel/tst_qsortfilterproxymodel.cpp b/tests/auto/qsortfilterproxymodel/tst_qsortfilterproxymodel.cpp
index e99e9d6..b7839f7 100644
--- a/tests/auto/qsortfilterproxymodel/tst_qsortfilterproxymodel.cpp
+++ b/tests/auto/qsortfilterproxymodel/tst_qsortfilterproxymodel.cpp
@@ -135,6 +135,7 @@ private slots:
     void task251296_hiddenChildren();
     void task252507_mapFromToSource();
     void task255652_removeRowsRecursive();
+    void taskQTBUG_6205_doubleProxySelectionSetSourceModel();
 
 protected:
     void buildHierarchy(const QStringList &data, QAbstractItemModel *model);
@@ -2815,5 +2816,41 @@ void tst_QSortFilterProxyModel::task255652_removeRowsRecursive()
     delete pItem11;
 }
 
+void tst_QSortFilterProxyModel::taskQTBUG_6205_doubleProxySelectionSetSourceModel()
+{
+    QStandardItemModel *model1 = new QStandardItemModel;
+    QStandardItem *parentItem = model1->invisibleRootItem();
+    for (int i = 0; i < 4; ++i) {
+        QStandardItem *item = new QStandardItem(QString("model1 item %0").arg(i));
+        parentItem->appendRow(item);
+        parentItem = item;
+    }
+
+    QStandardItemModel *model2 = new QStandardItemModel;
+    QStandardItem *parentItem2 = model2->invisibleRootItem();
+    for (int i = 0; i < 4; ++i) {
+        QStandardItem *item = new QStandardItem(QString("model2 item %0").arg(i));
+        parentItem2->appendRow(item);
+        parentItem2 = item;
+    }
+
+    QSortFilterProxyModel *toggleProxy = new QSortFilterProxyModel;
+    toggleProxy->setSourceModel(model1);
+
+    QSortFilterProxyModel *proxyModel = new QSortFilterProxyModel;
+    proxyModel->setSourceModel(toggleProxy);
+
+    QModelIndex mi = proxyModel->index(0, 0, proxyModel->index(0, 0, proxyModel->index(0, 0)));
+    QItemSelectionModel ism(proxyModel);
+    ism.select(mi, QItemSelectionModel::Select);
+    QModelIndexList mil = ism.selectedIndexes();
+    QCOMPARE(mil.count(), 1);
+    QCOMPARE(mil.first(), mi);
+
+    toggleProxy->setSourceModel(model2);
+    // No crash, it's good news!
+    QVERIFY(ism.selection().isEmpty());
+}
+
 QTEST_MAIN(tst_QSortFilterProxyModel)
 #include "tst_qsortfilterproxymodel.moc"