Saxon

It has taken me a long time to isolate a test case for this bug.

It originally presented as a random failure. With Saxon 11.5 (run-115.sh), running the XSpec test causes a random failure in the 693rd test. Every attempt to reduce or simplify the test that I've tried so far has caused the test to succeed.

On a whim, I tried it with Saxon 12 (run-12.sh) fully expecting it to succeed. Instead it fails quickly with a NPE:

java.lang.NullPointerException
	at net.sf.saxon.expr.parser.LoopLifter.markDependencies(LoopLifter.java:221)
	at net.sf.saxon.expr.parser.LoopLifter.gatherInfo(LoopLifter.java:171)
	at net.sf.saxon.expr.parser.LoopLifter.gatherInfo(LoopLifter.java:174)
	at net.sf.saxon.expr.parser.LoopLifter.gatherInfo(LoopLifter.java:174)
	at net.sf.saxon.expr.parser.LoopLifter.gatherInfo(LoopLifter.java:174)
	at net.sf.saxon.expr.parser.LoopLifter.gatherInfo(LoopLifter.java:174)
	at net.sf.saxon.expr.parser.LoopLifter.gatherInfo(LoopLifter.java:174)
	at net.sf.saxon.expr.parser.LoopLifter.gatherInfo(LoopLifter.java:174)
	at net.sf.saxon.expr.parser.LoopLifter.gatherInfo(LoopLifter.java:174)
	at net.sf.saxon.expr.parser.LoopLifter.gatherInfo(LoopLifter.java:153)
	at net.sf.saxon.expr.parser.LoopLifter.process(LoopLifter.java:53)
	at net.sf.saxon.expr.parser.ExpressionTool.optimizeComponentBody(ExpressionTool.java:978)
	at net.sf.saxon.style.XSLTemplate.optimize(XSLTemplate.java:1014)
	at net.sf.saxon.style.PrincipalStylesheetModule.optimizeTopLevel(PrincipalStylesheetModule.java:1496)
	at net.sf.saxon.style.PrincipalStylesheetModule.compile(PrincipalStylesheetModule.java:1315)
	at net.sf.saxon.style.Compilation.compilePackage(Compilation.java:324)
	at net.sf.saxon.style.StylesheetModule.loadStylesheet(StylesheetModule.java:246)
	at net.sf.saxon.style.Compilation.compileSingletonPackage(Compilation.java:113)
	at net.sf.saxon.s9api.XsltCompiler.compile(XsltCompiler.java:969)
	at net.sf.saxon.Transform.doTransform(Transform.java:777)
	at net.sf.saxon.Transform.main(Transform.java:83)

Is this related to the failure in Saxon 11.5? I've no idea.