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
}	
	
	Object evaluate( IConditionalExpression expr )
	{
		return context.evaluateCondExpr( expr );
	}
	/**
	 * Calculate the bookmark value which is set to
	 * <code>ReportItemContent</code> if the bookmark is not null
	 * 
	 * @param item
	 *            the ReportItemContent object
	 */
	protected void processBookmark( ReportItemDesign item, IContent itemContent )
	{
		String bookmark = item.getBookmark( );
		if ( bookmark != null )
		{
			Object tmp = evaluate( bookmark );
			if ( tmp != null && !tmp.equals( "" ) )
			{
				itemContent.setBookmark( tmp.toString( ) );
			}
			else
			{
				context.addException( new EngineException(
						"Bookmark can not be null or empty." ) );
			}
		}
		String toc = item.getTOC( );