Bug 203709 NullPointerException in TableAreaLayout
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/layout/pdf/cache/TableAreaLayout.java
if(firstRow && existDropCells()&&(!LayoutUtil.isRepeatableRow( (IRowContent)rowArea.getContent( ))))
		{
			mergeDropCell(rowArea);
		}
		
	}
	private int getHeightOfEmptyRow( Row row )
	{
		int heightOfEmptyRow = 0;
		for(int i=startCol; i<=endCol; i++)
		{
			CellArea cell = row.getCell( i );
			if ( cell == null )
				continue;
			IStyle style = cell.getStyle( );
			int bottomBorderWidth = PropertyUtil.getDimensionValue( style
					.getProperty( StyleConstants.STYLE_BORDER_BOTTOM_WIDTH ) );
			int topBorderWidth = PropertyUtil.getDimensionValue( style
					.getProperty( StyleConstants.STYLE_BORDER_TOP_WIDTH ) );
			int heightOfEmptyCell = topBorderWidth + bottomBorderWidth;
			heightOfEmptyRow = Math.max( heightOfEmptyCell, heightOfEmptyRow );
		}
		return heightOfEmptyRow;
	}
	private boolean isEmptyRow( Row row )
	{
		for(int i=startCol; i<=endCol; i++)
		{
			CellArea cell = row.getCell( i );
			if ( cell != null && !isDropCell( cell )