Bug 125272 [Viewers] AbstractTreeViewer needs remove(Object parentElement, Object[] childElements)
There is an add(Object parentElement, Object[] childElements) but no corresponding remove(). Without this method, if you have an element that appears under multiple parents, the only way to get model and viewer in sync after removing the element from just one of its parents is calling refresh().
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
if (expanded.containsKey(elementChildren[i])) {
                        setExpanded(items[i], true);
                    }
                }
            }
        }
        
        if (widget == tree && oldCnt == 0 && getItemCount(tree) != 0) {
            
            tree.setRedraw(false);
            tree.setRedraw(true);
        }
    }
    /**
     * Updates the "+"/"-" icon of the tree node from the given element. It
     * calls <code>isExpandable</code> to determine whether an element is
     * expandable.
     * 
     * @param item
     *           the item
     * @param element
     *           the element
     */
    protected void updatePlus(Item item, Object element) {
        boolean hasPlus = getItemCount(item) > 0;
        boolean needsPlus = isExpandable(element);
        boolean removeAll = false;
        boolean addDummy = false;
        Object data = item.getData();
        if (data != null && equals(element, data)) {