Bug 134266 [Wizard] Page description not set if page message already set
Since page messages such as errors and warnings used to be displayed in the same widget as the page description, code was put in place in WizardDialog#updateDescriptionMessage() to avoid setting the page description if there was already a message. As of 3.2 M6 there is a separate widget for displaying error and warning messages and so the page description should always be set.
bundles/org.eclipse.jface/src/org/eclipse/jface/wizard/WizardDialog.java
}
    }
    /**
     * Calculates the difference in size between the given
     * page and the page container. A larger page results 
     * in a positive delta.
     *
     * @param page the page
     * @return the size difference encoded
     *   as a <code>new Point(deltaWidth,deltaHeight)</code>
     */
    private Point calculatePageSizeDelta(IWizardPage page) {
        Control pageControl = page.getControl();
        if (pageControl == null) {
			
            return new Point(0, 0);
		}
        Point contentSize = pageControl.computeSize(SWT.DEFAULT, SWT.DEFAULT,
                true);
        Rectangle rect = pageContainerLayout.getClientArea(pageContainer);
        Point containerSize = new Point(rect.width, rect.height);
        return new Point(Math.max(0, contentSize.x - containerSize.x), Math
                .max(0, contentSize.y - containerSize.y));
    }
    /* (non-Javadoc)
     * Method declared on Dialog.
     */
    protected void cancelPressed() {
        if (activeRunningOperations <= 0) {