Bug 239945 [Coolbar] ArrayIndexOutOfBoundsException -1 in CoolBarManager.update
bundles/org.eclipse.jface/src/org/eclipse/jface/action/CoolBarManager.java
* 
     * @param iterator
     *            the list iterator.
     */
    private void collapseSeparators(ListIterator iterator) {
        while (iterator.hasNext()) {
            IContributionItem item = (IContributionItem) iterator.next();
            if (!item.isSeparator()) {
                iterator.previous();
                return;
            }
        }
    }
    /**
     * Returns whether the cool bar control has been created and not yet
     * disposed.
     * 
     * @return <code>true</code> if the control has been created and not yet
     *         disposed, <code>false</code> otherwise
     */
    private boolean coolBarExist() {
        return coolBar != null && !coolBar.isDisposed();
    }
    /**
     * Creates and returns this manager's cool bar control. Does not create a
     * new control if one already exists.
     * 
     * @param parent
     *            the parent control
     * @return the cool bar control