Saxon

If you download this project:

https://github.com/AntennaHouse/pdf5-ml/tree/develop-glossarylist-201703

and try to compile a new transformer from "com.antennahouse.pdf5.ml\xsl\dita2fo_import.xsl" using Saxin PE 9.7.0.15 you get:

java.lang.NullPointerException: Internal error: expression () has no retained static context
	at net.sf.saxon.expr.Expression.getPackageData(Expression.java:1129)
	at net.sf.saxon.expr.instruct.Choose.optimize(Choose.java:485)
	at net.sf.saxon.expr.Operand.optimize(Operand.java:200)
	at net.sf.saxon.expr.Expression.optimizeChildren(Expression.java:515)
	at net.sf.saxon.expr.instruct.Block.optimize(Block.java:566)
	at net.sf.saxon.expr.parser.ExpressionTool.optimizeComponentBody(ExpressionTool.java:1087)
	at net.sf.saxon.style.XSLTemplate.optimize(XSLTemplate.java:820)
	at net.sf.saxon.style.PrincipalStylesheetModule.optimizeTopLevel(PrincipalStylesheetModule.java:1374)
	at net.sf.saxon.style.PrincipalStylesheetModule.compile(PrincipalStylesheetModule.java:1224)
	at net.sf.saxon.style.Compilation.compilePackage(Compilation.java:265)
	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:859)
	at net.sf.saxon.jaxp.SaxonTransformerFactory.newTemplates(SaxonTransformerFactory.java:177)
	at net.sf.saxon.jaxp.SaxonTransformerFactory.newTransformer(SaxonTransformerFactory.java:131)

With Saxon 9.6 this issue cannot be reproduced according to our end user.