DO NOT REPLY [Bug 23778] New: - Assertion failed in FormatterTreeWalker while traversing a xalan:nodeset()

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http://nagoya.apache.org/bugzilla/show_bug.cgi?id=23778

Assertion failed in FormatterTreeWalker while traversing a xalan:nodeset()

           Summary: Assertion failed in FormatterTreeWalker while traversing
                    a xalan:nodeset()
           Product: XalanC
           Version: 1.6
          Platform: Other
        OS/Version: Other
            Status: NEW
          Severity: Normal
          Priority: Other
         Component: XalanC
        AssignedTo: xalan-dev@xml.apache.org
        ReportedBy: ts@edvwl.de


Assertion failed: node != 0, file $XALANCROOT\src\xalanc\XMLSuppo
rt\FormatterTreeWalker.cpp, line 192:

bool
FormatterTreeWalker::endNode(const XalanNode*	node)
{
	assert(node != 0);
	...
}



Sample Code samples/ExternalFunction/ExternalFunction.cpp, only class 
FunctionAsctime must be overwritten with this code snippet:

#include <xalanc/XMLSupport/FormatterToXML.hpp>
#include <xalanc/XMLSupport/FormatterTreeWalker.hpp>
#include <xalanc/PlatformSupport/XalanOutputStreamPrintWriter.hpp>
#include <xalanc/PlatformSupport/XalanStdOutputStream.hpp>

// This class defines a function that runs the C function
// asctime() using the current system time.
class FunctionAsctime : public Function
{
public:

	/**
	 * Execute an XPath function object.  The function must return a valid
	 * object.  Extension functions should override this version of execute
(),
	 * rather than one of the other calls designed for a specific number of
	 * arguments.
	 *
	 * @param executionContext executing context
	 * @param context          current context node
	 * @param args             vector of pointers to XObject arguments
	 * @param locator		   Locator for the XPath expression 
that contains the function call
	 * @return                 pointer to the result XObject
	 */
	virtual XObjectPtr
	execute(
			XPathExecutionContext&		
	executionContext,
			XalanNode*					
	context,
			const XObjectArgVectorType&		args,
			const LocatorType*			
	locator) const
	{

	XALAN_USING_XALAN(FormatterToXML)
	XALAN_USING_XALAN(FormatterTreeWalker)
	XALAN_USING_XALAN(XalanStdOutputStream)
	XALAN_USING_XALAN(XalanOutputStreamPrintWriter)
	XALAN_USING_XALAN(XObject)

	XalanStdOutputStream			theStream(std::cerr);
	XalanOutputStreamPrintWriter	thePrintWriter(theStream);
	FormatterToXML					theFormatter
(thePrintWriter);
	FormatterTreeWalker				theWalker(theFormatter);
	
	assert( args.size() == 1 );
	assert( args[0].null() == false );
	assert( args[0]->getType() == XObject::eObjectType::eTypeNodeSet );
	assert( args[0]->nodeset().item(0) != NULL );

	theFormatter.setShouldWriteXMLHeader(true);
	theFormatter.startDocument();
	theWalker.traverseSubtree(args[0]->nodeset().item(0));
	theFormatter.endDocument();

	return executionContext.getXObjectFactory().createString(XalanDOMString
("asctime()"));

	}

#if !defined(XALAN_NO_USING_DECLARATION)
	using Function::execute;
#endif

	/**
	 * Create a copy of the function object.
	 *
	 * @return pointer to the new object
	 */
#if defined(XALAN_NO_COVARIANT_RETURN_TYPE)
	virtual Function*
#else
	virtual FunctionAsctime*
#endif
	clone() const
	{
		return new FunctionAsctime(*this);
	}

protected:

	/**
	 * Get the error message to report when
	 * the function is called with the wrong
	 * number of arguments.
	 *
	 * @return function error message
	 */
	const XalanDOMString
	getError() const
	{
		return StaticStringToDOMString(XALAN_STATIC_UCODE_STRING("The 
asctime() function accepts one argument!"));
	}

private:

	// Not implemented...
	FunctionAsctime&
	operator=(const FunctionAsctime&);

	bool
	operator==(const FunctionAsctime&) const;
};



Sample Stylesheet (samples/ExternalFunction/foo.xsl, added an asctime param):
<?xml version="1.0"?> 
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0" 
xmlns:xalan="http://xml.apache.org/xalan"
				xmlns:external="http://ExternalFunction.xalan-
c++.xml.apache.org"
        exclude-result-prefixes="external">

  <xsl:template match="area">
    <xsl:choose>
	  <xsl:when test="function-available('external:square-root') and 
function-available('external:cube')"> 
        <given>
          The area of each face of the cube is <xsl:value-of select="@value"/>
          <xsl:text> square units </xsl:text> <xsl:value-of select="@units"/>. 
        </given>    
        <result>
          Accordingly, the length of each side is <xsl:value-of 
select="external:square-root(@value)"/>
          <xsl:text> </xsl:text><xsl:value-of select="@units"/> and the volume 
of the cube is 
          <xsl:value-of select="external:cube(external:square-root(@value))"/>
          <xsl:text> cubic </xsl:text> <xsl:value-of select="@units"/>.
        </result>
	  </xsl:when>
	  <xsl:otherwise>
        <result>
		  The functions external:square-root() and external cube() are 
not available!
		</result>
	  </xsl:otherwise>
    </xsl:choose>
  </xsl:template>

  <xsl:template match="now">       
    <xsl:choose>
	  <xsl:when test="function-available('external:asctime')"> 
        <when>
          <xsl:variable 
name="samplenode"><root><traverse>me</traverse></root></xsl:variable>
          Date and time when we figured all this out: <xsl:value-of 
select="external:asctime(xalan:nodeset($samplenode))"/>.
        </when>
	  </xsl:when>
	  <xsl:otherwise>
        <result>
		  The function external:asctime() is not available!
		</result>
	  </xsl:otherwise>
    </xsl:choose>
  </xsl:template>

</xsl:stylesheet>