Fix bug when resetting QSortFilterProxyModel

If multiple proxies are connected to one source model which gets reset,
the order of execution of the sourceModelAboutToBeReset slots could cause
QPersistentModelIndexes to be invalidated in one proxy model before the
same slot is executed in the other proxy model.

Additionally, the persistent indexes in the QSFPM are invalidated before
the persistent indexes in the source model. This patch makes them
invalidated afterward now, which makes more sense.

Merge-request: 503
Reviewed-by: Olivier Goffart <ogoffart@trolltech.com>

1 files changed, 87 insertions, 0 deletions

diff --git a/tests/auto/qsortfilterproxymodel/tst_qsortfilterproxymodel.cpp b/tests/auto/qsortfilterproxymodel/tst_qsortfilterproxymodel.cpp
index 56eaf25..2339b21 100644
--- a/tests/auto/qsortfilterproxymodel/tst_qsortfilterproxymodel.cpp
+++ b/tests/auto/qsortfilterproxymodel/tst_qsortfilterproxymodel.cpp
@@ -139,6 +139,8 @@ private slots:
     void taskQTBUG_7537_appearsAndSort();
     void taskQTBUG_7716_unnecessaryDynamicSorting();
 
+    void testMultipleProxiesWithSelection();
+
 protected:
     void buildHierarchy(const QStringList &data, QAbstractItemModel *model);
     void checkHierarchy(const QStringList &data, const QAbstractItemModel *model);
@@ -2951,5 +2953,90 @@ void tst_QSortFilterProxyModel::taskQTBUG_7716_unnecessaryDynamicSorting()
     }
 }
 
+class SelectionProxyModel : QAbstractProxyModel
+{
+    Q_OBJECT
+public:
+    SelectionProxyModel()
+        : QAbstractProxyModel(), selectionModel(0)
+    {
+    }
+
+    QModelIndex mapFromSource(QModelIndex const&) const
+    { return QModelIndex(); }
+
+    QModelIndex mapToSource(QModelIndex const&) const
+    { return QModelIndex(); }
+
+    QModelIndex index(int, int, const QModelIndex&) const
+    { return QModelIndex(); }
+
+    QModelIndex parent(const QModelIndex&) const
+    { return QModelIndex(); }
+
+    int rowCount(const QModelIndex&) const
+    { return 0; }
+
+    int columnCount(const QModelIndex&) const
+    { return 0; }
+
+    void setSourceModel( QAbstractItemModel *sourceModel )
+    {
+        beginResetModel();
+        disconnect( sourceModel, SIGNAL(modelAboutToBeReset()), this, SLOT(sourceModelAboutToBeReset()) );
+        QAbstractProxyModel::setSourceModel( sourceModel );
+        connect( sourceModel, SIGNAL(modelAboutToBeReset()), this, SLOT(sourceModelAboutToBeReset()) );
+        endResetModel();
+    }
+
+    void setSelectionModel( QItemSelectionModel *_selectionModel )
+    {
+        selectionModel = _selectionModel;
+    }
+
+private slots:
+    void sourceModelAboutToBeReset()
+    {
+        QVERIFY( selectionModel->selectedIndexes().size() == 1 );
+        beginResetModel();
+    }
+
+    void sourceModelReset()
+    {
+        endResetModel();
+    }
+
+private:
+    QItemSelectionModel *selectionModel;
+
+};
+
+void tst_QSortFilterProxyModel::testMultipleProxiesWithSelection()
+{
+    QStringListModel model;
+    const QStringList initial = QString("bravo charlie delta echo").split(" ");
+    model.setStringList(initial);
+
+    QSortFilterProxyModel proxy;
+    proxy.setSourceModel( &model );
+
+    SelectionProxyModel proxy1;
+    QSortFilterProxyModel proxy2;
+
+    // Note that the order here matters. The order of the sourceAboutToBeReset
+    // exposes the bug in QSortFilterProxyModel.
+    proxy2.setSourceModel( &proxy );
+    proxy1.setSourceModel( &proxy );
+
+    QItemSelectionModel selectionModel(&proxy2);
+    proxy1.setSelectionModel( &selectionModel );
+
+    selectionModel.select( proxy2.index( 0, 0 ), QItemSelectionModel::Select );
+
+    // trick the proxy into emitting begin/end reset signals.
+    proxy.setSourceModel(0);
+
+}
+
 QTEST_MAIN(tst_QSortFilterProxyModel)
 #include "tst_qsortfilterproxymodel.moc"