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
} else {
            
            removeAll = true;
            addDummy = needsPlus;
            
            setExpanded(item, false);
        }
        if (removeAll) {
            
            Item[] items = getItems(item);
            for (int i = 0; i < items.length; i++) {
                if (items[i].getData() != null) {
					disassociate(items[i]);
				}
                items[i].dispose();
            }
        }
        if (addDummy) {
			newItem(item, SWT.NULL, -1); 
		}
    }
    /**
     * Gets the expanded elements that are visible to the user. An expanded
     * element is only visible if the parent is expanded.
     * 
     * @return the visible expanded elements
     * @since 2.0
     */
    public Object[] getVisibleExpandedElements() {
        ArrayList v = new ArrayList();