ITS Filter: java.util.EmptyStackException thrown

With ITS configuration:

<its:withinTextRule selector="//tag" withinText="yes"/>

and content:

<tag>Text</tag>

the

java.util.EmptyStackException
	at java.base/java.util.Stack.peek(Stack.java:102)
	at net.sf.okapi.filters.its.ITSFilter.processElementTag(ITSFilter.java:888)
	at net.sf.okapi.filters.its.ITSFilter.process(ITSFilter.java:404)
	at net.sf.okapi.filters.its.ITSFilter.next(ITSFilter.java:190)

occurs on extraction.

Examples can be found below:

okf_xml_tag-with-text.fprm

tag-with-text.xml