QMap - check if iterator arguments are valid (in debugmode)

This patch adds a debug-tests in erase, insert (with hint)
and insertMulti (with hint) that ensures the iterator-argument
is valid (and e.g not from another map)

Change-Id: I7920131bc9712543183cabf13c7603bd0e12880d
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/tools/qmap.h

@@ -557,6 +557,18 @@ public:
 
 private:
     void detach_helper();
+    bool isValidIterator(const const_iterator &ci) const
+    {
+#if defined(QT_DEBUG) && !defined(Q_MAP_NO_ITERATOR_DEBUG)
+        const QMapNodeBase *n = ci.i;
+        while (n->parent())
+            n = n->parent();
+        return n->left == d->root();
+#else
+        Q_UNUSED(ci);
+        return true;
+#endif
+    }
 };
 
 template <class Key, class T>
@@ -670,6 +682,8 @@ typename QMap<Key, T>::iterator QMap<Key, T>::insert(const_iterator pos, const K
     if (d->ref.isShared())
         return this->insert(akey, avalue);
 
+    Q_ASSERT_X(isValidIterator(pos), "QMap::insert", "The specified const_iterator argument 'it' is invalid");
+
     if (pos == constEnd()) {
         // Hint is that the Node is larger than (or equal to) the largest value.
         Node *n = static_cast<Node *>(pos.i->left);
@@ -753,6 +767,8 @@ typename QMap<Key, T>::iterator QMap<Key, T>::insertMulti(const_iterator pos, co
     if (d->ref.isShared())
         return this->insertMulti(akey, avalue);
 
+    Q_ASSERT_X(isValidIterator(pos), "QMap::insertMulti", "The specified const_iterator argument 'pos' is invalid");
+
     if (pos == constEnd()) {
         // Hint is that the Node is larger than (or equal to) the largest value.
         Node *n = static_cast<Node *>(pos.i->left);
@@ -895,6 +911,8 @@ Q_OUTOFLINE_TEMPLATE typename QMap<Key, T>::iterator QMap<Key, T>::erase(iterato
     if (it == iterator(d->end()))
         return it;
 
+    Q_ASSERT_X(isValidIterator(const_iterator(it)), "QMap::erase", "The specified iterator argument 'it' is invalid");
+
     Node *n = it.i;
     ++it;
     d->deleteNode(n);

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

@@ -0,0 +1,111 @@
+/****************************************************************************
+**
+** Copyright (C) 2012 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.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//#define Q_NO_DEBUGMAP_PARENT_TEST
+// Comment in line above to skip the parent test.
+#include <QtCore/QMap>
+#include <QDebug>
+
+void noBugErase()
+{
+    QMap<int, int> a, b;
+    a[10] = 11;
+    a[11] = 12;
+    b = a;
+    b.erase(b.begin());
+}
+
+void noBugInsertWithHints()
+{
+    QMap<int, int> a;
+    QMap<int, int> b;
+    for (int u = 100; u < 10000; u += 20)
+        a.insert(u, u);
+    b = a;
+    QMap<int, int>::const_iterator b_ite(b.begin()); // b.begin() ensures correct detach()
+    ++b_ite;
+    b.insert(b_ite, 501, 501);
+    b.insert(b_ite, 115, 115);
+    QMap<int, int> c;
+    c = b;
+    c.setSharable(false);
+}
+
+void testInsertWithHintCorruption()
+{
+    qDebug() << "Starting testInsertWithHintCorruption";
+
+    QMap<int, int> a;
+    QMap<int, int> b;
+    for (int u = 100; u < 10000; u += 20)
+        a.insert(u, u);
+    b = a;
+    QMap<int, int>::const_iterator b_ite = b.constBegin();
+    ++b_ite;
+    b.insert(b_ite, 501, 501);
+    b.insert(b_ite, 115, 115); // insert with wrong hint.
+    QMap<int, int> c;
+    c = b;
+    c.setSharable(false);
+    qDebug() << "End of testInsertWithHintCorruption - failed silently";
+}
+
+void testEraseCorruption()
+{
+    qDebug() << "Starting testEraseCorruption";
+
+    QMap<int, int> a, b;
+    a[10] = 11;
+    a[11] = 12;
+    b = a;
+    b.erase(a.begin());
+    qDebug() << "End of testEraseCorruption - failed silently";
+}
+
+int main()
+{
+    noBugErase();
+    noBugInsertWithHints();
+
+    // testEraseCorruption();
+    testInsertWithHintCorruption();
+    return 0;
+}

tests/manual/corelib/tools/qmap/qmaptest.pro

@@ -0,0 +1,2 @@
+TEMPLATE = app
+SOURCES = main.cpp