Bug 81426 Package Explorer shows nothing after drill into working set, then show projects
I200412160800 - switch Package Explorer to working sets - context menu > Go Into a working set - Show > Projects -> view is empty -> view toolbar button 'Up to Working Sets' does not do anything
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerPart.java
getTree().setSelection((TreeItem[])toSelect.toArray(new TreeItem[toSelect.size()]));
		}
	    private Widget internalFindChild(Widget parent, Object element) {
	        Item[] items = getChildren(parent);
	        for (int i = 0; i < items.length; i++) {
	            Item item = items[i];
	            Object data = item.getData();
	            if (data != null && equals(data, element))
	                return item;
	        }
	        return null;
	    }
		private CustomHashtable createRootAccessedMap(TreePath[] paths) {
			CustomHashtable result= new CustomHashtable(getComparer());
			for (int i= 0; i < paths.length; i++) {
				TreePath path= paths[i];
				Object root= path.getFirstSegment();
				if (root != null) {
					result.put(root, path);
				}
			}
			return result;
		}
	}
 
	/* (non-Javadoc)
	 * Method declared on IViewPart.
	 */
	private boolean fLinkingEnabled;
    public void init(IViewSite site, IMemento memento) throws PartInitException {