From 52c66e85156eb0547777ada07fe67e5e5ef653da Mon Sep 17 00:00:00 2001
From: "Raschbauer, Reinhard" <reinhard.raschbauer@bbv.ch>
Date: Wed, 17 May 2017 11:03:02 +0200
Subject: [PATCH] QAbstractItemView: fix nullptr violation

If in a slot connected to QAbstractItemView::clicked
QAbstractItemView::setModel(nullptr) is called the method
QAbstractItemView::mouseReleaseEvent will cause a segmentation fault.
The problem is that the method QAbstractItemView::model used in
QAbstractItemView::mouseReleaseEvent will return a nullptr if a null
model was set. The solution is to used d->model since it is always a
valid model. (See line d->model =
(model ? model : QAbstractItemModelPrivate::staticEmptyModel());
in method QAbstractItemView::setModel)

Change-Id: I6f01bdeac64495ee4a76adcc7bf8da8a7719ef4d
Reviewed-by: David Faure <david.faure@kdab.com>
---
 src/widgets/itemviews/qabstractitemview.cpp   |  2 +-
 .../tst_qabstractitemview.cpp                 | 25 +++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/src/widgets/itemviews/qabstractitemview.cpp b/src/widgets/itemviews/qabstractitemview.cpp
index f056b7e5e5..25587a281d 100644
--- a/src/widgets/itemviews/qabstractitemview.cpp
+++ b/src/widgets/itemviews/qabstractitemview.cpp
@@ -1925,7 +1925,7 @@ void QAbstractItemView::mouseReleaseEvent(QMouseEvent *event)
         QStyleOptionViewItem option = d->viewOptionsV1();
         if (d->pressedAlreadySelected)
             option.state |= QStyle::State_Selected;
-        if ((model()->flags(index) & Qt::ItemIsEnabled)
+        if ((d->model->flags(index) & Qt::ItemIsEnabled)
             && style()->styleHint(QStyle::SH_ItemView_ActivateItemOnSingleClick, &option, this))
             emit activated(index);
     }
diff --git a/tests/auto/widgets/itemviews/qabstractitemview/tst_qabstractitemview.cpp b/tests/auto/widgets/itemviews/qabstractitemview/tst_qabstractitemview.cpp
index f2cf78e8ac..83912fa2c3 100644
--- a/tests/auto/widgets/itemviews/qabstractitemview/tst_qabstractitemview.cpp
+++ b/tests/auto/widgets/itemviews/qabstractitemview/tst_qabstractitemview.cpp
@@ -153,6 +153,7 @@ private slots:
     void testClickToSelect();
     void testDialogAsEditor();
     void QTBUG46785_mouseout_hover_state();
+    void testClearModelInClickedSignal();
 };
 
 class MyAbstractItemDelegate : public QAbstractItemDelegate
@@ -2266,5 +2267,29 @@ void tst_QAbstractItemView::QTBUG46785_mouseout_hover_state()
     QTRY_VERIFY(delegate.m_paintedWithoutHover);
 }
 
+void tst_QAbstractItemView::testClearModelInClickedSignal()
+{
+    QStringList list{"A", "B"};
+    QStringListModel model(list);
+
+    QListView view;
+    view.setModel(&model);
+    view.show();
+
+    QWidget::connect(&view, &QListView::clicked, [&view](const QModelIndex &index)
+    {
+        view.setModel(nullptr);
+        QCOMPARE(index.data().toString(), QStringLiteral("B"));
+    });
+
+    QModelIndex index = view.model()->index(1, 0);
+    QVERIFY(index.isValid());
+    QPoint p = view.visualRect(index).center();
+
+    QTest::mouseClick(view.viewport(), Qt::LeftButton, Qt::NoModifier, p);
+
+    QCOMPARE(view.model(), nullptr);
+}
+
 QTEST_MAIN(tst_QAbstractItemView)
 #include "tst_qabstractitemview.moc"