Bug 32224 [Show In]Back-linking doesn't work for .class files in jars
Build 20030218 1. Enable back-linking in Package Explorer 2. Open Object (in rt.jar) Observe: An editor on Object.class opens (it shows the attached source). However Object.class is not shown in Package Explorer Note that Alt-Shift-s->Package Explorer doesn't work either.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerPart.java
if (part != null) {
				IWorkbenchPage page= getSite().getPage();
				page.bringToTop(part);
				if (obj instanceof IJavaElement) 
					EditorUtility.revealInEditor(part, (IJavaElement) obj);
			}
		}
	}
	private boolean isActivePart() {
		return this == getSite().getPage().getActivePart();
	}
	
	public void saveState(IMemento memento) {
		if (fViewer == null) {
			
			if (fMemento != null) 
				memento.putMemento(fMemento);
			return;
		}
		saveExpansionState(memento);
		saveSelectionState(memento);
		saveLayoutState(memento);
		saveLinkingEnabled(memento);
		
		
		fActionSet.saveFilterAndSorterState(memento);
	}
	
	private void saveLinkingEnabled(IMemento memento) {
		memento.putInteger(PreferenceConstants.LINK_PACKAGES_TO_EDITOR, fLinkingEnabled ? 1 : 0);