Bug 182687 Exception thrown out when preview crosstab with toc setting
When preview crosstab which has set the toc property, exception will be thrown. Engine need to handle the case during toc processing while no IR object is associated with current content object. java.lang.NullPointerException at org.eclipse.birt.report.engine.executor.ReportItemExecutor.startTOCEntry(ReportItemExecutor.java:591) at org.eclipse.birt.report.engine.executor.ExtendedItemExecutor.execute(ExtendedItemExecutor.java:140) at org.eclipse.birt.report.engine.internal.executor.l18n.LocalizedReportItemExecutor.execute(LocalizedReportItemExecutor.java:36) at org.eclipse.birt.report.engine.layout.html.HTMLPageLM.layoutChildren(HTMLPageLM.java:124) at org.eclipse.birt.report.engine.layout.html.HTMLPageLM.layout
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/executor/ReportItemExecutor.java
}
		InstanceID id = new InstanceID( pid, design == null ? -1 : design
				.getID( ), getDataID( ) );
		content.setInstanceID( id );
		content.setGenerateBy( design );
	}
	
	TOCEntry getParentTOCEntry()
	{
		if (parent instanceof ReportItemExecutor)
		{
			ReportItemExecutor parentExecutor = (ReportItemExecutor)parent;
			if (parentExecutor.tocEntry != null)
			{
				return parentExecutor.tocEntry;
			}
			return parentExecutor.getParentTOCEntry();
		}
		return null;
	}
	/**
	 * starts a TOC entry, mostly used for non-leaf TOC entry, which can not be
	 * closed until its children have been written.
	 * 
	 * @param content
	 *            report item content object
	 */
	protected void startTOCEntry( IContent content )
	{
		TOCBuilder tocBuilder = context.getTOCBuilder( );