DO NOT REPLY [Bug 13711] New: - Incorrect validation of func:function

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http://nagoya.apache.org/bugzilla/show_bug.cgi?id=13711

Incorrect validation of func:function

           Summary: Incorrect validation of func:function
           Product: XalanJ2
           Version: 2.4
          Platform: PC
        OS/Version: Windows NT/2K
            Status: NEW
          Severity: Major
          Priority: Other
         Component: org.apache.xalan.processor
        AssignedTo: xalan-dev@xml.apache.org
        ReportedBy: avandenhoven@cucbc.com


Currently, if a func:function block includes the following:

<xsl:variable name="tfilepath">
  <xsl:choose>
    <xsl:when test="contains($ref, '#')">
      <xsl:value-of select="substring-before($ref,'#')"/>
    </xsl:when>
    <xsl:otherwise>
      <xsl:value-of select="$ref"/>
    </xsl:otherwise>
  </xsl:choose>
</xsl:variable>

It throws "misplaced literal result in a func:function container." This is 
wrong since nothing in a variable is a result. 

The problem here seems to be in the following snippet from 
org.apache.xalan.processor.ProcessorExsltFunction.validate:

 if (elem instanceof ElemValueOf ||
  (elem instanceof ElemLiteralResult || elem instanceof ElemElement)
          && !(ancestorIsOk(elem)))

This is like saying:
	if (x || y && !z)

And I'm not sure the logic is explicit enough to be correct. Not to mention the 
fact that the grouping seems to be a little odd. It would be better, I think to 
use:
 if (( elem instanceof ElemValueOf 
    || elem instanceof ElemLiteralResult 
    || elem instanceof ElemElement)
    && !(ancestorIsOk(elem)))

In addition the validation in incomplete. The EXSLT pages for func: says:

Begin Quote:
Function Results

The content of the func:function element is a template. When the function is 
called, the template is instantiated to give the result of the function. The 
template is instantiated with the context node from the expression in which the 
function was called as the current node, and with the context node list from 
the expression in which the function was called as the current node list. 

It is an error if the instantiation of the template results in the generation 
of result nodes.
...
:End Quote

Now my reading of this suggests that you should also invalidate for anything 
that results in a node of any sort being generated. You should be checking for:

xsl:element
xsl:attribute 
xsl:text
xsl:processing-instruction
xsl:comment
xsl:copy
xsl:value-of
xsl:number
xsl:apply-templates
xsl:apply-import
xsl:call-templates
xsl:text

All these should fail unless they are children of result, param or
variable. Now the if statement from above (if my quick survey of the
source code was correct) should probably be:
	if((elem instanceof ElemApplyImport
	 || elem instanceof ElemApplyTemplates
	 || elem instanceof ElemAttribute
	 || elem instanceof ElemCallTemplate
	 || elem instanceof ElemComment
	 || elem instanceof ElemCopy
	 || elem instanceof ElemCopyOf
	 || elem instanceof ElemElement
	 || elem instanceof ElemLiteralResult
	 || elem instanceof ElemNumber
	 || elem instanceof ElemPI
	 || elem instanceof ElemText
	 || elem instanceof ElemTextLiteral
	 || elem instanceof ElemVariable)
	&& !(ancestorIsOk(elem)))

This should work and meat the requirements of EXSLT

Adam