Eliminate QTreeWidget drag crash

In QTreeViewPrivate::adjustViewOptionsForIndex() wrong index had been
used when referencing to array of viewItems. Variable row is set to the
index of the QModelIndex, however it is not as same as the index in
viewItems[] when there was hidden item in treeWidget. Index of viewItems[]
should be used here. Unit test is added as well.

Change-Id: Idc7eda979e7d09c5a07bd6dffd92b7abbac10e67
Task-Id: QTBUG-25333
Reviewed-by: Girish Ramakrishnan <girish.1.ramakrishnan@nokia.com>
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>

2 files changed, 43 insertions, 1 deletions

diff --git a/src/widgets/itemviews/qtreeview.cpp b/src/widgets/itemviews/qtreeview.cpp
index f2a2ef2ca2..62d94d0004 100644
--- a/src/widgets/itemviews/qtreeview.cpp
+++ b/src/widgets/itemviews/qtreeview.cpp
@@ -1357,7 +1357,7 @@ QItemViewPaintPairs QTreeViewPrivate::draggablePaintPairs(const QModelIndexList
 
 void QTreeViewPrivate::adjustViewOptionsForIndex(QStyleOptionViewItemV4 *option, const QModelIndex &current) const
 {
-    const int row = current.row();
+    const int row = viewIndex(current); // get the index in viewItems[]
     option->state = option->state | (viewItems.at(row).expanded ? QStyle::State_Open : QStyle::State_None)
                                   | (viewItems.at(row).hasChildren ? QStyle::State_Children : QStyle::State_None)
                                   | (viewItems.at(row).hasMoreSiblings ? QStyle::State_Sibling : QStyle::State_None);
diff --git a/tests/auto/widgets/itemviews/qtreeview/tst_qtreeview.cpp b/tests/auto/widgets/itemviews/qtreeview/tst_qtreeview.cpp
index b0b55a73bc..320483bb14 100644
--- a/tests/auto/widgets/itemviews/qtreeview/tst_qtreeview.cpp
+++ b/tests/auto/widgets/itemviews/qtreeview/tst_qtreeview.cpp
@@ -239,6 +239,7 @@ private slots:
     void taskQTBUG_9216_setSizeAndUniformRowHeightsWrongRepaint();
     void taskQTBUG_11466_keyboardNavigationRegression();
     void taskQTBUG_13567_removeLastItemRegression();
+    void taskQTBUG_25333_adjustViewOptionsForIndex();
 };
 
 class QtTestModel: public QAbstractItemModel
@@ -4008,5 +4009,46 @@ void tst_QTreeView::taskQTBUG_13567_removeLastItemRegression()
     CHECK_VISIBLE(198, 0);
 }
 
+// From QTBUG-25333 (QTreeWidget drag crashes when there was a hidden item in tree)
+// The test passes simply if it doesn't crash, hence there are no calls
+// to QCOMPARE() or QVERIFY().
+// Note: define QT_BUILD_INTERNAL to run this test
+void tst_QTreeView::taskQTBUG_25333_adjustViewOptionsForIndex()
+{
+    PublicView view;
+    QStandardItemModel model;
+    QStandardItem *item1 = new QStandardItem("Item1");
+    QStandardItem *item2 = new QStandardItem("Item2");
+    QStandardItem *item3 = new QStandardItem("Item3");
+    QStandardItem *data1 = new QStandardItem("Data1");
+    QStandardItem *data2 = new QStandardItem("Data2");
+    QStandardItem *data3 = new QStandardItem("Data3");
+
+    // Create a treeview
+    model.appendRow(QList<QStandardItem*>() << item1 << data1 );
+    model.appendRow(QList<QStandardItem*>() << item2 << data2 );
+    model.appendRow(QList<QStandardItem*>() << item3 << data3 );
+
+    view.setModel(&model);
+
+    // Hide a row
+    view.setRowHidden(1, QModelIndex(), true);
+    view.expandAll();
+
+    view.show();
+
+#ifdef QT_BUILD_INTERNAL
+    {
+        QStyleOptionViewItemV4 option;
+
+        view.aiv_priv()->adjustViewOptionsForIndex(&option, model.indexFromItem(item1));
+
+        view.aiv_priv()->adjustViewOptionsForIndex(&option, model.indexFromItem(item3));
+    }
+#endif
+
+}
+
+
 QTEST_MAIN(tst_QTreeView)
 #include "tst_qtreeview.moc"