Bug 129886 Delect a column contain the marge row which contain some item, Error message pop up
Details: Delect a column contain the marge row which contain some item, Error message pop up Setp: 1.New a library and add a 3*3 grid 2.Insert a label in cell(1,1) 3.Marge the cell of (1,1) and (1,2) 4.Delete column 1. Actual result: An error message pop up
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/editors/schematic/editparts/TableEditPart.java
TableCellEditPart fg = (TableCellEditPart) itr.next( );
			fg.updateBlankString( );
		}
	}
	/**
	 * Gets the top, left, right, bottom of edit part.
	 * 
	 * @param parts
	 * @return cell edit parts.
	 */
	public TableCellEditPart[] getMinAndMaxNumber( TableCellEditPart[] parts )
	{
		if ( parts == null || parts.length == 0 )
		{
			return null;
		}
		int size = parts.length;
		TableCellEditPart leftTopPart = parts[0];
		TableCellEditPart leftBottomPart = parts[0];
		TableCellEditPart rightBottomPart = parts[0];
		TableCellEditPart rightTopPart = parts[0];
		for ( int i = 1; i < size; i++ )
		{
			TableCellEditPart part = parts[i];
			if ( part == null )
			{
				continue;
			}
			if ( part.getRowNumber( ) <= leftTopPart.getRowNumber( )
					&& part.getColumnNumber( ) <= leftTopPart.getColumnNumber( ) )