Bug 203709 NullPointerException in TableAreaLayout
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/layout/pdf/cache/TableAreaLayout.java
if(lastRow!=null)
			{
				lastCell = lastRow.getCell( i );
			}
			CellArea cell = row.getCell( i );
			if(cell!=null && (cell.getRowSpan( )>1 || isDropCell( cell )))
			{
				hasDropCell = true;
			}
			if(lastCell!=null &&(lastCell.getRowSpan( )>1 || isDropCell( lastCell )))
			{
				if(cell==null)
				{
					DummyCell dummyCell = null;
					if(lastCell instanceof DummyCell)
					{
						DummyCell refDummy = ((DummyCell)lastCell);
						dummyCell = new DummyCell(refDummy.getCell( ));
						if(lastCell.getRowSpan()>0)
						{
							dummyCell.setRowSpan( lastCell.getRowSpan( )-1 );
						}
						else
						{
							dummyCell.setRowSpan( lastCell.getRowSpan( ) );
						}
						dummyCell.setHeight( refDummy.getHeight( ) - rowHeight );
					}
					else
					{