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
}
			Object parent= internalGetParent(element);
			
			 
			if (parent instanceof IPackageFragment) {
				Object grandparent= internalGetParent(parent);
				
				
				if (parent.equals(fInput)) {
					postRefresh(parent);
				} else {
					
					if (fViewer.testFindItem(parent) == null)
						postRefresh(grandparent);
					else {
						postRefresh(parent);
					}	
				}
				return;				
			} else {  
				postAdd(parent, element);
			}
		}
		if (element instanceof ICompilationUnit) {
			if (getProvideWorkingCopy()) {
				IJavaElement original= ((IWorkingCopy)element).getOriginalElement();
				if (original != null)
					element= original;
			}
			if (kind == IJavaElementDelta.CHANGED) {