QHash - checks if iterator argument is valid (in debugmode)

This checks if the iterator argument in erase is valid in debug mode.

Change-Id: I8768f4263d1464ff78986a1a30702e210e561dc1
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/tools/qhash.h

@@ -509,6 +509,24 @@ private:
     static void deleteNode2(QHashData::Node *node);
 
     static void duplicateNode(QHashData::Node *originalNode, void *newNode);
+
+    bool isValidIterator(const iterator &it) const
+    {
+#if defined(QT_DEBUG) && !defined(Q_HASH_NO_ITERATOR_DEBUG)
+        union {
+            QHashData *iteratorHashData;
+            QHashData::Node *node;
+        };
+        node = it.i;
+        while (node->next)
+            node = node->next;
+
+        return (iteratorHashData == d);
+#else
+        Q_UNUSED(it);
+        return true;
+#endif
+    }
 };
 
 
@@ -831,6 +849,8 @@ Q_OUTOFLINE_TEMPLATE T QHash<Key, T>::take(const Key &akey)
 template <class Key, class T>
 Q_OUTOFLINE_TEMPLATE typename QHash<Key, T>::iterator QHash<Key, T>::erase(iterator it)
 {
+    Q_ASSERT_X(isValidIterator(it), "QHash::erase", "The specified const_iterator argument 'it' is invalid");
+
     if (it == iterator(e))
         return it;
 

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

@@ -0,0 +1,85 @@
+/****************************************************************************
+**
+** 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 <QHash>
+
+void testEraseNoError()
+{
+    QHash<int, int> a;
+
+    a.insert(100, 100);
+    a.insert(101, 200);
+    a.insert(5, 50);
+    a.insertMulti(5, 60);
+    a.insertMulti(5, 70);
+    a.insertMulti(5, 80);
+
+    QHash<int, int>::iterator i = a.begin();
+    while (i.key() != 5)
+        ++i;
+    ++i;
+    a.erase(i);
+
+    qDebug() << "Erase - got no errors on iterator check";
+}
+
+void testErase()
+{
+    QHash<int, int> a, b;
+    a.insert(5, 50);
+    a.insert(6, 60);
+    a.insert(7, 70);
+    b = a;
+    a.erase(a.begin());
+    b.erase(b.end() - 1);
+    qDebug() << "Erase - Executing line with error now.";
+    a.erase(b.begin());
+}
+
+
+int main()
+{
+    testEraseNoError();
+    testErase();
+    return 0;
+}

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

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