Fix QQmlDelegateModel getting out of sync

Fixes a regression introduced by a0aefe1, which caused that the
source data model and adaptorModel could sometimes get out of
sync.

Change-Id: Ia6b5fc380cc6cf6549ae857e6da54e088a5dadb5
Reviewed-by: Alan Alpert (Personal) <416365416c@gmail.com>

6 files changed, 273 insertions, 8 deletions

diff --git a/src/qml/types/qqmldelegatemodel.cpp b/src/qml/types/qqmldelegatemodel.cpp
index 4591d42710..23bdeb55b2 100644
--- a/src/qml/types/qqmldelegatemodel.cpp
+++ b/src/qml/types/qqmldelegatemodel.cpp
@@ -1558,12 +1558,7 @@ void QQmlDelegateModel::_q_layoutChanged(const QList<QPersistentModelIndex> &par
             if (i == index.row())
                 continue;
 
-            QVector<Compositor::Insert> inserts;
-            QVector<Compositor::Remove> removes;
-            d->m_compositor.listItemsMoved(&d->m_adaptorModel, i, index.row(), 1, &removes, &inserts);
-            if (!removes.isEmpty() || !inserts.isEmpty()) {
-                d->itemsMoved(removes, inserts);
-            }
+            _q_itemsMoved(i, index.row(), 1);
         }
 
         d->m_storedPersistentIndexes.clear();
diff --git a/tests/auto/quick/qquicklistview/data/layoutChangeSort.qml b/tests/auto/quick/qquicklistview/data/layoutChangeSort.qml
new file mode 100644
index 0000000000..e54f164e45
--- /dev/null
+++ b/tests/auto/quick/qquicklistview/data/layoutChangeSort.qml
@@ -0,0 +1,58 @@
+import QtQuick 2.0
+import QtQml.Models 2.1
+
+Rectangle {
+    id: root
+    width: 240
+    height: 320
+    color: "#ffffff"
+
+
+    Component {
+        id: myDelegate
+        Rectangle {
+            id: wrapper
+            objectName: "wrapper"
+            height: 20
+            width: 240
+            Text {
+                objectName: "delegateText"
+                text: display
+            }
+            color: ListView.isCurrentItem ? "lightsteelblue" : "white"
+        }
+    }
+
+    DelegateModel {
+        id: delegateModel
+        objectName: "delegateModel"
+        model: testModel
+        delegate: myDelegate
+    }
+
+    ListView {
+        id: list
+        objectName: "listView"
+        model: delegateModel;
+        focus: true
+        anchors.fill: parent
+
+
+        section {
+            property: "SortRole";
+            delegate: Rectangle {
+                width: parent.width;
+                height: 20;
+                color: "steelblue";
+
+                Text {
+                    anchors {
+                        fill: parent;
+                        margins: 5;
+                    }
+                    text: section;
+                }
+            }
+        }
+    }
+}
diff --git a/tests/auto/quick/qquicklistview/qquicklistview.pro b/tests/auto/quick/qquicklistview/qquicklistview.pro
index 2ae04d32fe..c9b634b9e8 100644
--- a/tests/auto/quick/qquicklistview/qquicklistview.pro
+++ b/tests/auto/quick/qquicklistview/qquicklistview.pro
@@ -4,10 +4,13 @@ TARGET = tst_qquicklistview
 macx:CONFIG -= app_bundle
 
 HEADERS += incrementalmodel.h \
-           proxytestinnermodel.h
+           proxytestinnermodel.h \
+           randomsortmodel.h
 SOURCES += tst_qquicklistview.cpp \
            incrementalmodel.cpp \
-           proxytestinnermodel.cpp
+           proxytestinnermodel.cpp \
+           randomsortmodel.cpp
+
 
 include (../../shared/util.pri)
 include (../shared/util.pri)
diff --git a/tests/auto/quick/qquicklistview/randomsortmodel.cpp b/tests/auto/quick/qquicklistview/randomsortmodel.cpp
new file mode 100644
index 0000000000..e9082e39c9
--- /dev/null
+++ b/tests/auto/quick/qquicklistview/randomsortmodel.cpp
@@ -0,0 +1,107 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "randomsortmodel.h"
+
+RandomSortModel::RandomSortModel(QObject* parent):
+    QAbstractListModel(parent)
+{
+    for (int i = 0; i < 10; ++i) {
+        mData.append(qMakePair(QString::fromLatin1("Item %1").arg(i), i * 10));
+    }
+}
+
+QHash<int, QByteArray> RandomSortModel::roleNames() const
+{
+    QHash<int,QByteArray> roles = QAbstractItemModel::roleNames();
+    roles[Qt::UserRole] = "SortRole";
+    return roles;
+}
+
+
+int RandomSortModel::rowCount(const QModelIndex& parent) const
+{
+    if (!parent.isValid())
+        return mData.count();
+
+    return 0;
+}
+
+QVariant RandomSortModel::data(const QModelIndex& index, int role) const
+{
+    if (!index.isValid()) {
+        return QVariant();
+    }
+
+    if (index.row() >= mData.count()) {
+        return QVariant();
+    }
+
+    if (role == Qt::DisplayRole) {
+        return QString::fromLatin1("%1 (weight %2)").arg(mData[index.row()].first).arg(mData[index.row()].second);
+    } else if (role == Qt::UserRole) {
+        return mData[index.row()].second;
+    }
+
+    return QVariant();
+}
+
+void RandomSortModel::randomize()
+{
+    const int row = qrand() % mData.count();
+    int random;
+    bool exists = false;
+    // Make sure we won't end up with two items with the same weight, as that
+    // would make unit-testing much harder
+    do {
+        exists = false;
+        random = qrand() % (mData.count() * 10);
+        QList<QPair<QString, int> >::ConstIterator iter, end;
+        for (iter = mData.constBegin(), end = mData.constEnd(); iter != end; ++iter) {
+            if ((*iter).second == random) {
+                exists = true;
+                break;
+            }
+        }
+    } while (exists);
+    mData[row].second = random;
+    Q_EMIT dataChanged(index(row, 0), index(row, 0));
+}
diff --git a/tests/auto/quick/qquicklistview/randomsortmodel.h b/tests/auto/quick/qquicklistview/randomsortmodel.h
new file mode 100644
index 0000000000..8d28698d9b
--- /dev/null
+++ b/tests/auto/quick/qquicklistview/randomsortmodel.h
@@ -0,0 +1,64 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef RANDOMSORTMODEL_H
+#define RANDOMSORTMODEL_H
+
+#include <QAbstractListModel>
+
+class RandomSortModel : public QAbstractListModel
+{
+    Q_OBJECT
+
+public:
+    explicit RandomSortModel(QObject* parent = 0);
+    QHash<int, QByteArray> roleNames() const;
+
+    QVariant data(const QModelIndex& index, int role) const;
+    int rowCount(const QModelIndex& parent = QModelIndex()) const;
+
+    void randomize();
+
+  private:
+    QList<QPair<QString, int> > mData;
+};
+
+#endif // RANDOMSORTMODEL_H
diff --git a/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp b/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
index b561258351..4fcf186690 100644
--- a/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
+++ b/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
@@ -55,6 +55,7 @@
 #include "../shared/visualtestutil.h"
 #include "incrementalmodel.h"
 #include "proxytestinnermodel.h"
+#include "randomsortmodel.h"
 #include <math.h>
 
 Q_DECLARE_METATYPE(Qt::LayoutDirection)
@@ -231,6 +232,8 @@ private slots:
     void QTBUG_38209();
     void programmaticFlickAtBounds();
 
+    void layoutChange();
+
 private:
     template <class T> void items(const QUrl &source);
     template <class T> void changed(const QUrl &source);
@@ -7365,6 +7368,41 @@ void tst_QQuickListView::programmaticFlickAtBounds()
     QVERIFY(!spy.wait(100));
 }
 
+void tst_QQuickListView::layoutChange()
+{
+    RandomSortModel *model = new RandomSortModel;
+    QSortFilterProxyModel *sortModel = new QSortFilterProxyModel;
+    sortModel->setSourceModel(model);
+    sortModel->setSortRole(Qt::UserRole);
+    sortModel->setDynamicSortFilter(true);
+    sortModel->sort(0);
+
+    QScopedPointer<QQuickView> window(createView());
+    window->rootContext()->setContextProperty("testModel", QVariant::fromValue(sortModel));
+    window->setSource(testFileUrl("layoutChangeSort.qml"));
+    window->show();
+    QVERIFY(QTest::qWaitForWindowExposed(window.data()));
+
+    QQuickListView *listview = window->rootObject()->findChild<QQuickListView *>("listView");
+    QVERIFY(listview);
+
+    for (int iter = 0; iter < 100; iter++) {
+        for (int i = 0; i < sortModel->rowCount(); ++i) {
+            QQuickItem *delegateItem = listview->itemAt(10, 10 + 2 * i * 20 + 20); // item + group
+            QVERIFY(delegateItem);
+            QQuickItem *delegateText = delegateItem->findChild<QQuickItem *>("delegateText");
+            QVERIFY(delegateText);
+
+            QCOMPARE(delegateText->property("text").toString(),
+                     sortModel->index(i, 0, QModelIndex()).data().toString());
+        }
+
+        model->randomize();
+        listview->forceLayout();
+        QTest::qWait(5); // give view a chance to update
+    }
+}
+
 QTEST_MAIN(tst_QQuickListView)
 
 #include "tst_qquicklistview.moc"