Bug 100565 [Viewers] Tree viewer selection not revealed if unchanged
[RC3] Steps: 1. Check out org.eclipse.ui.workbench 2. Open Workbench.java 3. Ctrl-O to open Quick Outline 4. Type "r", note that the field "runEventLoop" is the first match 5. Type "u", note that the field is not shown anymore 6. Type arrow-down key, note that you cannot see the selected entry
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
*         children
     */
    private Item rightMostVisibleDescendent(Item item) {
        Item[] children = getItems(item);
        if (getExpanded(item) && children != null && children.length > 0) {
            return rightMostVisibleDescendent(children[children.length - 1]);
        }
        return item;
    }
    
    public Item scrollDown(int x, int y) {
        Item current = getItem(x, y);
        if (current != null) {
            Item next = getNextItem(current, true);
            showItem(next == null ? current : next);
            return next;
        }
        return null;
    }
    
    public Item scrollUp(int x, int y) {
        Item current = getItem(x, y);
        if (current != null) {
            Item previous = getPreviousItem(current);
            showItem(previous == null ? current : previous);
            return previous;
        }
        return null;
    }
    /**