IDEA-78638: XSLT debug: Xalan: Variables view shows only default value of template parameter

XSLT debug. Provide any .xml source and .xsl with a breakpoint like shown below:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
	<xsl:output method="xml" indent="yes"/>

	<xsl:template match="/">
		<xsl:call-template name="called">
			<xsl:with-param name="p1">Non-default value.</xsl:with-param>
		</xsl:call-template>
	</xsl:template>

	<xsl:template name="called">
		<xsl:param name="p1">Default value.</xsl:param>
		<called><xsl:value-of select="$p1"/></called> <!-- breakpoint -->
	</xsl:template>
</xsl:stylesheet> 

Debug with Xalan, stop on the breakpoint.
Variables view shows template parameter "p1" with value "Default value."
While actually it's "Non-default value." and Watches show correct value.

Saxon and Saxon9 have no such problem.
(BTW, is it Ok that Xalan shows parameter type as "RTREEFRAG"?)
112.121.