Bug 239945 [Coolbar] ArrayIndexOutOfBoundsException -1 in CoolBarManager.update
bundles/org.eclipse.jface/src/org/eclipse/jface/action/CoolBarManager.java
if (oldIndices[i] != wrapIndices[i]) {
                    shouldUpdate = true;
                    break;
                }
            }
        } else {
            shouldUpdate = true;
        }
        if (shouldUpdate) {
            coolBar.setWrapIndices(wrapIndices);
        }
    }
    
	private boolean isChildVisible(IContributionItem item) {
		Boolean v;
		
		IContributionManagerOverrides overrides = getOverrides();
		if(overrides == null) {
			v = null;
		} else {
			v = getOverrides().getVisible(item); 
		}
		
		if (v != null) {
			return v.booleanValue();
		}
		return item.isVisible();
	}
}