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
ViewerSorter sorter = getSorter();
		if (sorter instanceof TreePathViewerSorter) {
			TreePathViewerSorter tpvs = (TreePathViewerSorter) sorter;
			
			
			result = (Object[]) result.clone();
			
			TreePath path = null;
	    	if (parentElementOrTreePath instanceof TreePath) {
	    		path = (TreePath) parentElementOrTreePath;
			} else {
				Object parent = parentElementOrTreePath;
				Widget w = internalGetWidgetToSelect(parent);
				if (w != null) {
					path = internalGetSorterParentPath(w, sorter);
				}
				if (path == null) {
					path = TreePath.EMPTY.createChildPath(parentElementOrTreePath);
				}
			}
	    	tpvs.sort(this, path, result);
		} else if (sorter != null) {
			
			result = (Object[]) result.clone();
			sorter.sort(this, result);
		}
		return result;
	}
	
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