Bug 182190 [StatusHandling] [Wizards] getControl assert on wizard page has no message
M6 If you forget to set the control on your wizard page our assert gives no feedback. We need an error message.
bundles/org.eclipse.jface/src/org/eclipse/jface/wizard/WizardDialog.java
*/
    public void updateButtons() {
        boolean canFlipToNextPage = false;
        boolean canFinish = wizard.canFinish();
        if (backButton != null) {
			backButton.setEnabled(currentPage.getPreviousPage() != null);
		}
        if (nextButton != null) {
            canFlipToNextPage = currentPage.canFlipToNextPage();
            nextButton.setEnabled(canFlipToNextPage);
        }
        finishButton.setEnabled(canFinish);
        
        if (canFlipToNextPage && !canFinish) {
			getShell().setDefaultButton(nextButton);
		} else {
			getShell().setDefaultButton(finishButton);
		}
    }
    /**
     * Update the message line with the page's description.
     * <p>
     * A discription is shown only if there is no message or error message.
     * </p>
     */
    private void updateDescriptionMessage() {
        pageDescription = currentPage.getDescription();
		setMessage(pageDescription);
    }
    /* (non-Javadoc)