Bug 97821 [package explorer] eternal loop when recreating deleted compilation unit
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerPart.java
super.internalUpdate(item, element, properties);
				for (Iterator iter= stable.iterator(); iter.hasNext();) {
					Widget additionalItem= (Widget)iter.next();
					super.internalUpdate(additionalItem, element, properties);
				}
			}
		}
		public ISelection getSelection() {
			IContentProvider cp= getContentProvider();
			if (!(cp instanceof IMultiElementTreeContentProvider)) {
				return super.getSelection();
			}
			Control control = getControl();
			if (control == null || control.isDisposed()) {
				return StructuredSelection.EMPTY;
			}
			Tree tree= getTree();
			TreeItem[] selection= tree.getSelection();
			List result= new ArrayList(selection.length);
			List treePaths= new ArrayList();
			for (int i= 0; i < selection.length; i++) {
				TreeItem item= selection[i];
				Object element= getElement(item);
				if (element == null)
					continue;
				if (!result.contains(element)) {
					result.add(element);
				}
				treePaths.add(createTreePath(item));
			}