Bug 130976 [Viewers] Error is calculation of parent path when calling TreePathViewerSorter
There is an error in the parent path calculation in AbstractTreeViewer#getSortedChildren. If the input of the viewer is passed, a tee path of length one is passed to the sorter but a null should be passed (as mentioned in the method spec). I will attach a patch.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
*
     * @param widget 
     *           the widget for the parent element
     * @param parentElementOrTreePath
     *           the parent element
     * @param childElements
     *           the child elements to add
     * @since 3.1
     */
    protected void internalAdd(Widget widget, Object parentElementOrTreePath, Object[] childElements) {
    	Object parent;
    	TreePath path;
    	if (parentElementOrTreePath instanceof TreePath) {
			path = (TreePath) parentElementOrTreePath;
			parent = path.getLastSegment();
		} else {
			parent = parentElementOrTreePath;
			path = null;
		}
    	
		
        
        if (widget instanceof Item) {
            Item ti = (Item) widget;
            if (!getExpanded(ti)) {
                boolean needDummy = isExpandable(ti, path, parent);
                boolean haveDummy = false;
                
                Item[] items = getItems(ti);
                for (int i = 0; i < items.length; i++) {