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
Widget w = findItem(parent);
    				if (w instanceof Item) {
    					Item item = (Item) w;
    					path = getTreePathFromItem(item);
    				}
    				if (path == null) {
    					path = new TreePath(new Object[] { parent });
    				}
    			}
    			Object[] result = tpcp.getChildren(path);
                if (result != null) {
					return result;
				}
    		} else if (cp instanceof ITreeContentProvider) {
    			ITreeContentProvider tcp = (ITreeContentProvider) cp;
                Object[] result = tcp.getChildren(parent);
                if (result != null) {
					return result;
				}
    		}
        }
        return new Object[0];
    }
    /**
     * Returns all selected items for the given SWT control.
     * 
     * @param control
     *           the control
     * @return the list of selected items
     */