Saxon

The dita test FO/xep step (FO_xep-none.xml is simplest) extracted from tests/john/dita/ATests is failing. Used the command:

-xsl:../DITA-OT1.8.5/plugins/org.dita.pdf2.SAXON/xsl/fo/topic2fo_shell_xep.xsl -s:stage1a.xml -t  -xsltversion:3.0 -diag:none/stats.xml -o:none/out.xml

fails during compilation with the following stack trace:

Generating byte code...
**** endMethod failed
Exception in thread "main" java.lang.AssertionError: The Label: returnNullItem has been used but not marked
	at com.saxonica.ee.bytecode.util.GeneratedMethodInfo.checkLabels(GeneratedMethodInfo.java:147)
	at com.saxonica.ee.bytecode.util.CompilerService.popCurrentMethodInfo(CompilerService.java:874)
	at com.saxonica.ee.bytecode.FilterExpressionCompiler.makeFilterIteratorClass(FilterExpressionCompiler.java:455)
	at com.saxonica.ee.bytecode.FilterExpressionCompiler.compileToIterator(FilterExpressionCompiler.java:366)
	at com.saxonica.ee.bytecode.util.CompilerService.compileToIterator(CompilerService.java:760)
	at com.saxonica.ee.bytecode.StaticFunctionCallCompiler.compileToIterator(StaticFunctionCallCompiler.java:57)
	at com.saxonica.ee.bytecode.util.CompilerService.compileToIterator(CompilerService.java:760)
	at com.saxonica.ee.bytecode.SlashExpressionCompiler.generateMappingFunction(SlashExpressionCompiler.java:115)
	at com.saxonica.ee.bytecode.SlashExpressionCompiler.compileToIterator(SlashExpressionCompiler.java:56)
	at com.saxonica.ee.bytecode.util.CompilerService.compileToIterator(CompilerService.java:760)
	at com.saxonica.ee.bytecode.DocumentSorterCompiler.compileToIterator(DocumentSorterCompiler.java:28)
	at com.saxonica.ee.bytecode.ExpressionCompiler.compileToLoop(ExpressionCompiler.java:226)
	at com.saxonica.ee.bytecode.util.CompilerService.compileToLoop(CompilerService.java:866)
	at com.saxonica.ee.bytecode.CountCompiler.compileToPrimitive(CountCompiler.java:45)
	at com.saxonica.ee.bytecode.ExpressionCompiler.compileItemFromInt(ExpressionCompiler.java:319)
	at com.saxonica.ee.bytecode.CountCompiler.compileToItem(CountCompiler.java:65)
	at com.saxonica.ee.bytecode.util.CompilerService.compileToItem(CompilerService.java:786)
	at com.saxonica.ee.bytecode.ArithmeticCompiler.compileToItem(ArithmeticCompiler.java:58)
	at com.saxonica.ee.bytecode.ToItemCompiler.compileToPush(ToItemCompiler.java:116)
	at com.saxonica.ee.bytecode.util.CompilerService.compileToPush(CompilerService.java:773)
	at com.saxonica.ee.bytecode.LetExpressionCompiler.compileToPush(LetExpressionCompiler.java:105)
	at com.saxonica.ee.bytecode.util.CompilerService.compileToPush(CompilerService.java:773)
	at com.saxonica.ee.bytecode.util.CompilerService.compileToByteCode(CompilerService.java:641)
	at com.saxonica.ee.optim.OptimizerEE.compileToByteCode(OptimizerEE.java:1460)
	at net.sf.saxon.style.XSLTemplate.generateByteCode(XSLTemplate.java:873)
	at net.sf.saxon.style.PrincipalStylesheetModule.compile(PrincipalStylesheetModule.java:1322)
	at net.sf.saxon.style.Compilation.compilePackage(Compilation.java:264)
	at net.sf.saxon.style.StylesheetModule.loadStylesheet(StylesheetModule.java:260)
	at net.sf.saxon.style.Compilation.compileSingletonPackage(Compilation.java:101)
	at net.sf.saxon.s9api.XsltCompiler.compile(XsltCompiler.java:856)
	at net.sf.saxon.Transform.doTransform(Transform.java:729)
	at net.sf.saxon.Transform.main(Transform.java:78)