Bug 32664 Package Explorer: hierarchical layout and back-linking don't work allways together.
The following triggers it: - initially 'flat layout' is used, 'link with editor' is on or off - open a java file - use 'collapse all' in the package explorer - select 'hierarchical layout' - switch 'link with editor' on or off&on -> no back-linking
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerContentProvider.java
*/
	private Object[] getWithParentsResources(Object[] existingObject, Object parent) {
		Object[] objects= super.getChildren(parent);
		List list= new ArrayList();
		
		for (int i= 0; i < objects.length; i++) {
			Object object= objects[i];
			if (!(object instanceof IPackageFragment)) {
				list.add(object);
			}
		}
		if (existingObject != null)
			list.addAll(Arrays.asList(existingObject));
		return list.toArray();
	}
	/* (non-Javadoc)
	 * Method declared on IContentProvider.
	 */
	public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
		super.inputChanged(viewer, oldInput, newInput);
		fPackageFragmentProvider.inputChanged(viewer, oldInput, newInput);
		fViewer= (TreeViewer)viewer;
		if (oldInput == null && newInput != null) {
			JavaCore.addElementChangedListener(this); 
		} else if (oldInput != null && newInput == null) {
			JavaCore.removeElementChangedListener(this); 
		}
		fInput= newInput;
	}