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
public boolean equals(Object a, Object b) {
				return ((TreePath)a).equals(((TreePath)b), comparer);
			}
			public int hashCode(Object element) {
				return ((TreePath)element).hashCode(comparer);
			}};
        CustomHashtable expandedTreePaths = new CustomHashtable(treePaths.length * 2 + 1, treePathComparer);
        for (int i = 0; i < treePaths.length; ++i) {
            TreePath treePath = treePaths[i];
            
            
            
            
            internalExpand(treePath, false);
            expandedTreePaths.put(treePath, treePath);
        }
        
        
        
        
        internalSetExpandedTreePaths(expandedTreePaths, getControl(), new TreePath(new Object[0]));
    }
	/**
     * Sets whether the node corresponding to the given element or tree path is expanded or
     * collapsed.
     * 
     * @param elementOrTreePath
     *           the element
     * @param expanded
     *           <code>true</code> if the node is expanded, and <code>false</code>