Bug 108624 [Coolbar] incorrect downcast in SubCoolBarManager.getStyle()
The downcast in this method public int getStyle() { // It is okay to cast down since we only accept coolBarManager objects in the // constructor return ((CoolBarManager) getParent()).getStyle(); } is not okay because the constructor accepts ICoolBarManager objects. Since ICoolBarManager has a method getStyle(), the downcast should be to ICoolBarManager, not to CoolBarManager.
bundles/org.eclipse.jface/src/org/eclipse/jface/action/SubCoolBarManager.java
ICoolBarManager {
    /**
     * Constructs a new manager.
     *
     * @param mgr the parent manager.  All contributions made to the 
     *      <code>SubCoolBarManager</code> are forwarded and appear in the
     *      parent manager.
     */
    public SubCoolBarManager(ICoolBarManager mgr) {
        super(mgr);
        Assert.isNotNull(mgr);