Throw an exception (warning) on XPATH match failure

[Federico Valido]

Hi!
I would like to get a warning when processing a <xsl:template 
match="xpath_expression"> that doesn't match with anything.
For example:
<xsl:template match="/myNode">
 ...
</xsl:template>
used with a xml that doesn't have any <myNode>
I've tried to implement a custom ErrorListener, but in my tests I 
didn't  get any calls to error(...) nor fatalError(...) nor warning(...).

Any suggestion?
An alternative is to have a DTD and use it to validate my xml, I know... 
But I need to get _Xalan_ to warn me when a match fails.

Thanks in advance