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
for (int i = 0; i < elements.length; i++) {
			boolean newItem = true;
			Object element = elements[i];
			int index;
			if(sorter == null){
				if(itemExists(items,element)){
					refresh(element);
					newItem = false;
				}
				index = -1;
			}
			else{
				lastInsertion = insertionPosition(items,sorter,lastInsertion, element, parentPath);
				
				if(lastInsertion == items.length) {
					index = -1;
				} else{
					while(lastInsertion < items.length && internalCompare(sorter,parentPath,element,items[lastInsertion].getData()) == 0){
						
						
						if (items[lastInsertion].getData().equals(element)) {
							
							refresh(element);
							newItem = false;
						}
						lastInsertion ++;
					}
					
					if(lastInsertion == items.length) {