[xsl] Unexpected MSXML Javascript extension results

["C. Edward Porter cep@xxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

Hello all,

We have an XSL transformation that runs using some form of MSXML for the
actual transformation. Given that MSXML is XSL 1.0, I am trying to code around
the fact that it lacks regular expression functions by writing a JavaScript
extension function to match Greek characters and wrap them in a span to avoid
them being wrongly transformed to capital letters by smallcap treatment on the
text around it. The JavaScript function I wrote appears to work fine if I run
it locally, but when run as part of the XSL, it's not recursing properly. I
don't have much of a way to debug this, so I'm hoping perhaps someone can
either recognize why I'm getting inconsistent recursion, or perhaps suggest an
alternative approach. Code/sample text below:

JavaScript Function:
 <msxsl:script language="javascript" implements-prefix="uspc"><![CDATA[
//Recursive function to wrap greek characters in nosmallcaps span
	function wrapGreek(str){
		var regex = /(.*)([N1-O	N-N)])(.*)/g;
		var m = regex.exec(str);
		var rStr = "";
		if(m != null){
			rStr = wrapGreek(m[1]);
		} else {
			rStr = str;
		}
		if(m != null) {
			rStr += '<span class="nosmallcaps">' + m[2] + '</span>' + m[3];
		}
			return "" + rStr;
	}
]]></msxsl:script>

Text template:
<xsl:template match="text()" priority="20">
	<xsl:variable name="textout">
		<xsl:value-of select="."/>
	</xsl:variable>
	<xsl:value-of disable-output-escaping="yes"
select="uspc:wrapGreek($textout)"/>
</xsl:template>

Sample Content:
This head composed correctly:
<title cid="pttFA"
id="GUID-04193AE6-05B6-44C1-AB2A-E8A900F93CE3">DESN1CRIPN1TION</title>

For this one, only the second alpha symbol was wrapped, so it did not recurse.
Copying this text to a JavaScript interpreter and running the function on it
in isolation does appear to recurse correctly.
<title cid="1IMidE" id="GUID-D279E612-1350-4709-B662-8FFEF76CD0C0">InfrN1ared
AbsoN1rption, <i cid="2KvZ79">Spectrophotometric Identification Tests,
Appendix IIIC</i></title>


Thanks in advance!
-Edward