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
postRefresh(element);
				updateSelection(delta);
				return;
			}
		}
		
		if ((element instanceof ICompilationUnit) || (element instanceof IClassFile))
			return;
			
		
		if (element instanceof IPackageFragmentRoot && ((flags & IJavaElementDelta.F_ARCHIVE_CONTENT_CHANGED) != 0)) {
			postRefresh(element);
			return;
		}
		
		if (element instanceof IPackageFragmentRoot && (((flags & IJavaElementDelta.F_SOURCEATTACHED) != 0 || ((flags & IJavaElementDelta.F_SOURCEDETACHED)) != 0)))
			postUpdateIcon(element);
			
		if (isClassPathChange(delta)) {
			  
			postRefresh(element.getJavaProject());
			return;
		}
		
		if (processResourceDeltas(delta.getResourceDeltas(), element))
			return;
		handleAffectedChildren(delta, element);
	}
		
	private void handleAffectedChildren(IJavaElementDelta delta, IJavaElement element) throws JavaModelException {