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diff --git a/src/xmlpatterns/expr/qnodesort.cpp b/src/xmlpatterns/expr/qnodesort.cpp
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+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Qt Software Information (qt-info@nokia.com)
+**
+** This file is part of the QtXmlPatterns module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** 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, Nokia gives you certain
+** additional rights. These rights are described in the Nokia Qt LGPL
+** Exception version 1.0, 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.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at qt-sales@nokia.com.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qcommonsequencetypes_p.h"
+#include "qdeduplicateiterator_p.h"
+#include "qnodesort_p.h"
+
+QT_BEGIN_NAMESPACE
+
+using namespace QPatternist;
+
+NodeSortExpression::NodeSortExpression(const Expression::Ptr &op) : SingleContainer(op)
+{
+}
+
+bool NodeSortExpression::lessThanUsingNodeModel(const Item &n1,
+ const Item &n2)
+{
+ Q_ASSERT(n1.isNode());
+ Q_ASSERT(n2.isNode());
+
+ if(n1.asNode().model() == n2.asNode().model())
+ return n1.asNode().compareOrder(n2.asNode()) == QXmlNodeModelIndex::Precedes;
+ else
+ {
+ /* The two nodes are from different trees. The sort order is implementation
+ * defined, but it must be stable.
+ *
+ * We do this by looking at the pointer difference. The value means nothing,
+ * but it is stable, and that's what we're looking for. */
+ return n1.asNode().model() - n2.asNode().model() < 0;
+ }
+}
+
+Item::Iterator::Ptr NodeSortExpression::evaluateSequence(const DynamicContext::Ptr &context) const
+{
+ Q_ASSERT_X(m_operand->staticType()->cardinality().allowsMany(), Q_FUNC_INFO,
+ "It makes no sense to sort a single node.");
+
+ Item::List nodes(m_operand->evaluateSequence(context)->toList());
+
+ if(nodes.isEmpty())
+ return CommonValues::emptyIterator;
+ else if(nodes.first().isAtomicValue())
+ return makeListIterator(nodes);
+ else
+ {
+ qSort(nodes.begin(), nodes.end(), lessThanUsingNodeModel);
+
+ return Item::Iterator::Ptr(new DeduplicateIterator(nodes));
+ }
+}
+
+Expression::Ptr NodeSortExpression::wrapAround(const Expression::Ptr &operand,
+ const StaticContext::Ptr &context)
+{
+ Q_ASSERT(operand);
+ Q_ASSERT(context);
+
+ const Expression::Ptr sort(new NodeSortExpression(operand));
+ context->wrapExpressionWith(operand.data(), sort);
+ return sort;
+}
+
+Expression::Ptr NodeSortExpression::compress(const StaticContext::Ptr &context)
+{
+ const Expression::Ptr me(SingleContainer::compress(context));
+
+ /* It make no sense to sort & deduplicate a single node. */
+ if(m_operand->staticType()->cardinality().allowsMany())
+ return me;
+ else
+ return m_operand;
+}
+
+SequenceType::Ptr NodeSortExpression::staticType() const
+{
+ return m_operand->staticType();
+}
+
+SequenceType::List NodeSortExpression::expectedOperandTypes() const
+{
+ SequenceType::List result;
+ result.append(CommonSequenceTypes::ZeroOrMoreItems);
+ return result;
+}
+
+ExpressionVisitorResult::Ptr
+NodeSortExpression::accept(const ExpressionVisitor::Ptr &visitor) const
+{
+ return visitor->visit(this);
+}
+
+Expression::Properties NodeSortExpression::properties() const
+{
+ /* The reason we disable elimination is that the assert for sorting a
+ * single node in evaluateSequence() triggers unless our compress() routine
+ * has been run. Anyhow, it's not that we would manage to write away anyway,
+ * since the node source in most(all?) cases prevents it.
+ */
+ return AffectsOrderOnly | DisableElimination;
+}
+
+QT_END_NAMESPACE