QList - check if iterators arguments are valid (in debugmode)

This adds a check of the iterator values in erase and insert.

Change-Id: I78403dcbd24fd7c6beb86d3c827a8e233963e770
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/tools/qlist.h

@@ -346,6 +346,11 @@ private:
     void node_destruct(Node *n);
     void node_copy(Node *from, Node *to, Node *src);
     void node_destruct(Node *from, Node *to);
+
+    bool isValidIterator(const iterator &i) const
+    {
+        return (constBegin().i <= i.i) && (i.i <= constEnd().i);
+    }
 };
 
 #if defined(Q_CC_BOR)
@@ -433,6 +438,8 @@ Q_INLINE_TEMPLATE QList<T> &QList<T>::operator=(const QList<T> &l)
 template <typename T>
 inline typename QList<T>::iterator QList<T>::insert(iterator before, const T &t)
 {
+    Q_ASSERT_X(isValidIterator(before), "QList::insert", "The specified iterator argument 'before' is invalid");
+
     int iBefore = int(before.i - reinterpret_cast<Node *>(p.begin()));
     Node *n = reinterpret_cast<Node *>(p.insert(iBefore));
     QT_TRY {
@@ -445,8 +452,11 @@ inline typename QList<T>::iterator QList<T>::insert(iterator before, const T &t)
 }
 template <typename T>
 inline typename QList<T>::iterator QList<T>::erase(iterator it)
-{ node_destruct(it.i);
- return reinterpret_cast<Node *>(p.erase(reinterpret_cast<void**>(it.i))); }
+{
+    Q_ASSERT_X(isValidIterator(it), "QList::erase", "The specified iterator argument 'it' is invalid");
+    node_destruct(it.i);
+    return reinterpret_cast<Node *>(p.erase(reinterpret_cast<void**>(it.i)));
+}
 template <typename T>
 inline const T &QList<T>::at(int i) const
 { Q_ASSERT_X(i >= 0 && i < p.size(), "QList<T>::at", "index out of range");
@@ -811,6 +821,9 @@ template <typename T>
 Q_OUTOFLINE_TEMPLATE typename QList<T>::iterator QList<T>::erase(typename QList<T>::iterator afirst,
                                                                  typename QList<T>::iterator alast)
 {
+    Q_ASSERT_X(isValidIterator(afirst), "QList::erase", "The specified iterator argument 'afirst' is invalid");
+    Q_ASSERT_X(isValidIterator(alast), "QList::erase", "The specified iterator argument 'alast' is invalid");
+
     for (Node *n = afirst.i; n < alast.i; ++n)
         node_destruct(n);
     int idx = afirst - begin();

tests/manual/corelib/tools/qlist/main.cpp

@@ -0,0 +1,71 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Thorbjørn Lund Martsum - tmartsum[at]gmail.com
+** 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 <QDebug>
+//#define QT_STRICT_ITERATORS
+#include <QVector>
+void testErase()
+{
+    QList<int> a, b;
+    a.append(5);
+    a.append(6);
+    a.append(7);
+    b = a;
+    a.erase(a.begin());
+    qDebug() << "erase - Executing line with error now.";
+    // a.erase(a.end());
+    a.erase(b.begin());
+}
+void testInsert()
+{
+    QList<int> a, b;
+    a.insert(a.begin(), 1);
+    a.insert(a.begin(), 2);
+    a.insert(a.end(), 3);
+    b = a;
+    qDebug() << "insert - Executing line with error now.";
+    a.insert(b.begin(), 4);
+}
+int main()
+{
+    // testErase();
+    testInsert();
+    return 0;
+}

tests/manual/corelib/tools/qlist/main.pro

@@ -0,0 +1 @@
+SOURCES = main.cpp