Bug 82706 [Wizards] WizardDialog: code inconsistent
As long as WizardDialog.updateTitleBar() is a public method (should it be?) it's not a bad idea to check dialog state in all appropriate places. Now: public void updateTitleBar() { String s = null; if(currentPage != null) s = currentPage.getTitle(); if (s == null) s = ""; //$NON-NLS-1$ setTitle(s); if(currentPage != null) setTitleImage(currentPage.getImage()); updateDescriptionMessage(); updateMessage(); } It accurately checks that currentPage != null, but forgets to do the same before calling of updateDescriptionMessage() method wich works with currentPage without any checking. This can cause NPE (which happened to me :-)).
bundles/org.eclipse.jface/src/org/eclipse/jface/wizard/WizardDialog.java
page.createControl(pageContainer);
            
            
            Assert.isNotNull(page.getControl());
            
            updateSize(page);
        }
        
        IWizardPage oldPage = currentPage;
        currentPage = page;
        currentPage.setVisible(true);
        if (oldPage != null)
            oldPage.setVisible(false);
        
        update();
    }
    /**	
     * Shows the starting page of the wizard.
     */
    private void showStartingPage() {
        currentPage = wizard.getStartingPage();
        if (currentPage == null) {
            
            return;
        }
        
        if (currentPage.getControl() == null) {
            currentPage.createControl(pageContainer);