Bug 147676 [regression]Visibility set in the first col will affect the second col
Description: Visibility set in the first col will affect the second col Steps to reproduce: 1. Insert a grid(3*3), insert contents to each cell. 2.Set the first col to hide all in visibility and preview Expected result: Only the first col is hidden. Actual result: The second col is hidden, too. If you set the second col in step2, the third col will disappear.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/layout/pdf/PDFTableLM.java
Iterator iter = dropList.iterator( );
		while ( iter.hasNext( ) )
		{
			DropCellInfo dropCell = (DropCellInfo) iter.next( );
			verticalAlign( dropCell.cell );
			iter.remove( );
		}
	}
	public void updateUnresolvedCell( int groupLevel, boolean dropAll )
	{
		String dropType = dropAll ? "all" : "detail"; 
		int dropValue = this.createDropID( groupLevel, dropType );
		removeDropAreaBySpan( dropValue );
		for ( int i = 0; i < this.columnNumber; i++ )
		{
			if ( currentRowContent[i] != null )
			{
				if ( dropValue == currentRowContent[i].rowSpan )
				{
					currentRowContent[i] = null;
				}
			}
		}
	}
	/**
	 * update row height
	 * 
	 * @param row
	 */
	public void updateRow( RowArea row, int specifiedHeight )