Handle overflow, underflow in XPath substring position, length.

third_party/WebKit/Source/core/xml/XPathPredicate.h

 /*
  * Copyright 2005 Frerich Raabe <raabe@kde.org>
  * Copyright (C) 2006 Apple Computer, Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef XPathPredicate_h
 #define XPathPredicate_h
 
+#include "core/CoreExport.h"
 #include "core/xml/XPathExpressionNode.h"
 #include "core/xml/XPathValue.h"
 
 namespace blink {
 
 namespace XPath {
 
-class Number final : public Expression {
+class CORE_EXPORT Number final : public Expression {
  public:
   explicit Number(double);
   DECLARE_VIRTUAL_TRACE();
 
  private:
   Value evaluate(EvaluationContext&) const override;
   Value::Type resultType() const override { return Value::NumberValue; }
 
   Value m_value;
 };
 
-class StringExpression final : public Expression {
+class CORE_EXPORT StringExpression final : public Expression {
  public:
   explicit StringExpression(const String&);
   DECLARE_VIRTUAL_TRACE();
 
  private:
   Value evaluate(EvaluationContext&) const override;
   Value::Type resultType() const override { return Value::StringValue; }
 
   Value m_value;
 };
@@ skipping 73 matching lines @@
 
  private:
   Member<Expression> m_expr;
 };
 
 }  // namespace XPath
 
 }  // namespace blink
 
 #endif  // XPathPredicate_h