Saving a document from a scheduler job generate a NPE on notifying the lucene plugin

2008-09-29 17:40:01,227 [http://localhost:8080/xwiki/bin/view/Main/] [DefaultQuartzScheduler_Worker-1] ERROR lucene.IndexUpdater             - error in notify 
java.lang.NullPointerException
	at org.xwiki.context.DefaultExecution.getContext(DefaultExecution.java:50)
	at com.xpn.xwiki.render.DefaultVelocityManager.getVelocityContext(DefaultVelocityManager.java:79)
	at com.xpn.xwiki.render.XWikiVelocityRenderer.render(XWikiVelocityRenderer.java:62)
	at com.xpn.xwiki.render.XWikiVelocityRenderer.interpret(XWikiVelocityRenderer.java:51)
	at com.xpn.xwiki.render.DefaultXWikiRenderingEngine.renderText(DefaultXWikiRenderingEngine.java:269)
	at com.xpn.xwiki.render.DefaultXWikiRenderingEngine.interpretText(DefaultXWikiRenderingEngine.java:175)
	at com.xpn.xwiki.doc.XWikiDocument.getDisplayTitle(XWikiDocument.java:566)
	at com.xpn.xwiki.plugin.lucene.IndexData.<init>(IndexData.java:69)
	at com.xpn.xwiki.plugin.lucene.DocumentData.<init>(DocumentData.java:35)
	at com.xpn.xwiki.plugin.lucene.IndexUpdater.add(IndexUpdater.java:473)
	at com.xpn.xwiki.plugin.lucene.IndexUpdater.notify(IndexUpdater.java:528)
	at com.xpn.xwiki.notify.DocChangeRule.verify(DocChangeRule.java:61)
	at com.xpn.xwiki.notify.XWikiNotificationManager.verify(XWikiNotificationManager.java:210)
	at com.xpn.xwiki.XWiki.saveDocument(XWiki.java:1295)
	at com.xpn.xwiki.api.Document.saveDocument(Document.java:1611)
	at com.xpn.xwiki.api.Document.save(Document.java:1568)
	at com.xpn.xwiki.api.Document.save(Document.java:1557)
	at gjdk.com.xpn.xwiki.api.Document_GroovyReflector.invoke(Unknown Source)
	at groovy.lang.MetaMethod.invoke(MetaMethod.java:111)
	at org.codehaus.groovy.runtime.MetaClassHelper.doMethodInvoke(MetaClassHelper.java:657)
	at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:363)
	at org.codehaus.groovy.runtime.Invoker.invokeMethod(Invoker.java:146)
	at org.codehaus.groovy.runtime.InvokerHelper.invokeMethod(InvokerHelper.java:104)
	at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethod(ScriptBytecodeAdapter.java:85)
	at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeNoArgumentsMethod(ScriptBytecodeAdapter.java:175)
	at Script1.run(Script1.groovy:3)
	at groovy.lang.GroovyShell.evaluate(GroovyShell.java:485)
	at groovy.lang.GroovyShell.evaluate(GroovyShell.java:460)
	at com.xpn.xwiki.plugin.scheduler.GroovyJob.execute(GroovyJob.java:83)
	at org.quartz.core.JobRunShell.run(JobRunShell.java:202)
	at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:529)