Bug 144556 [Dialogs] TitleAreaDialog fails to properly recreate when an instance is reopened
When a TitleAreaDialog is created, opened, closed and opened again on the same instance the messageArea is not properly checked against disposal when it is accessed in setWarningMessage throwing an SWTException for disposed when the message area is updated the second time the dialog is opened.
bundles/org.eclipse.jface/src/org/eclipse/jface/dialogs/TitleAreaDialog.java
private static final int H_GAP_IMAGE = 5;
    
    private static final int MIN_DIALOG_WIDTH = 350;
    
    private static final int MIN_DIALOG_HEIGHT = 150;
    static {
        ImageRegistry reg = JFaceResources.getImageRegistry();
        reg.put(DLG_IMG_TITLE_BANNER, ImageDescriptor.createFromFile(
                TitleAreaDialog.class, "images/title_banner.gif"));
    }
    private Label titleLabel;
    private Label titleImageLabel;
    
    private Image titleImage;
    private Label leftFillerLabel;
    private RGB titleAreaRGB;
    Color titleAreaColor;
    private String message = ""; 
    private String errorMessage;
    private Text messageLabel;
    private Composite workArea;
    
	private Composite titleArea;
    private Label messageImageLabel;
    private Image messageImage;
    private boolean showingError = false;
    
    private boolean showingWarning = false;
    private boolean titleImageLargest = true;