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
IJavaElementDelta[] affectedChildren= delta.getAffectedChildren();
		for (int i= 0; i < affectedChildren.length; i++) 
			return findAddedElement(affectedChildren[i]);
			
		return null;
	}
	/**
	 * Refreshes the Compilation unit corresponding to the workging copy
	 * @param iWorkingCopy
	 */
	private void refreshWorkingCopy(IWorkingCopy workingCopy) {
		IJavaElement original= workingCopy.getOriginalElement();
		if (original != null)
			postRefresh(original, false);
	}
	private boolean isWorkingCopy(IJavaElement element) {
		return (element instanceof IWorkingCopy) && ((IWorkingCopy)element).isWorkingCopy();
	}
	
	/**
	 * Updates the package icon
	 */
	 private void postUpdateIcon(final IJavaElement element) {
	 	postRunnable(new Runnable() {
			public void run() {
				
				Control ctrl= fViewer.getControl();
				if (ctrl != null && !ctrl.isDisposed()) 
					fViewer.update(element, new String[]{IBasicPropertyConstants.P_IMAGE});