Bug 198231 Exception when preview attached report in excel.[1203]
engine/org.eclipse.birt.report.engine.emitter.prototype.excel/src/org/eclipse/birt/report/engine/emitter/excel/layout/ExcelLayoutEngine.java
Rule rule = table.getColumnRule( col, span );
		addContainer( createContainer( rule, style ) );
	}
	public void endCell( )
	{
		endContainer( );
	}
	public void addRow( IStyle style )
	{
		XlsTable table = (XlsTable) containers.peek( );
		XlsContainer container = createContainer( table.getRule( ), style );
		container.setEmpty( false );
		addContainer( container );
	}
	public void endRow( )
	{
		synchronous( );
		endContainer( );
	}
	private void synchronous( )
	{
		Rule rule = getCurrentContainer( ).getRule( );
		int start = rule.getStart( );
		int end = rule.getEnd( );
		int startcol = axis.getCoordinate( start );
		int endcol = axis.getCoordinate( end );
		int max = 0;
		int len[] = new int[endcol - startcol];
		for ( int i = startcol; i < endcol; i++ )
		{