Bug 336684 [JFace] NPE in Tray Dialog
bundles/org.eclipse.jface/src/org/eclipse/jface/dialogs/TrayDialog.java
public void handleEvent(Event event) {
				if (event.detail != SWT.DRAG) {
					Rectangle clientArea = shell.getClientArea();
					int newWidth = clientArea.width - event.x - (sash.getSize().x + rightSeparator.getSize().x);
					if (newWidth != data.widthHint) {
						data.widthHint = newWidth;
						shell.layout();
					}
				}
			}
		});
		shellWidth = shell.getSize().x;
		
		resizeListener = new ResizeListener(data, shell);
		shell.addControlListener (resizeListener);
		   
		this.tray = tray;
		if (fHelpButton != null) {
			fHelpButton.setSelection(true);
		}
	}
	
	/**
	 * Sets whether or not context help is available for this dialog. This
	 * can affect whether or not the dialog will display additional help
	 * mechanisms such as a help control in the button bar.
	 * 
	 * @param helpAvailable whether or not context help is available for the dialog
	 */
	public void setHelpAvailable(boolean helpAvailable) {