Bug 166346 [Viewers] ViewerRow#getCell(Point) not working for Viewers without columns
If the viewer has no rows this should return not null but the ViewerCell at index 0
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/ViewerRow.java
/*
			 * (non-Javadoc)
			 * 
			 * @see org.eclipse.swt.events.DisposeListener#widgetDisposed(org.eclipse.swt.events.DisposeEvent)
			 */
			public void widgetDisposed(DisposeEvent e) {
				item.setData(ROWPART_KEY, null);
			}
		});
	}
	/**
	 * Get the bounds of the entry at the columnIndex,
	 * 
	 * @param columnIndex
	 * @return {@link Rectangle}
	 */
	public abstract Rectangle getBounds(int columnIndex);
	/**
	 * Return the bounds for the whole item.
	 * 
	 * @return {@link Rectangle}
	 */
	public abstract Rectangle getBounds();
	/**
	 * Return the item for the receiver.
	 * 
	 * @return {@link Item}
	 */
	public abstract Item getItem();
	/**