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
* some reasonable minimum.
     * 
     * @return the initial size of the dialog
     */
    protected Point getInitialSize() {
        Point shellSize = super.getInitialSize();
        return new Point(Math.max(
                convertHorizontalDLUsToPixels(MIN_DIALOG_WIDTH), shellSize.x),
                Math.max(convertVerticalDLUsToPixels(MIN_DIALOG_HEIGHT),
                        shellSize.y));
    }
    /**
     * Retained for backward compatibility.
     * 
     * Returns the title area composite. There is no composite in this
     * implementation so the shell is returned.
     * 
     * @return Composite
     * @deprecated
     */
    protected Composite getTitleArea() {
        return getShell();
    }
    /**
     * Returns the title image label.
     * 
     * @return the title image label
     */
    protected Label getTitleImageLabel() {
        return titleImageLabel;