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
while (element != null && fViewer.getSelection().isEmpty()) {
						
						element= getParent(element);
						if (element != null) {
							newSelection= new StructuredSelection(element);
							fViewer.setSelection(newSelection);
						}
					}
				} finally {
					fViewer.addSelectionChangedListener(fSelectionListener);
				}
				return true;
			}
		}
		return false;
	}
	/**
	 * Returns the element's parent.
	 * 
	 * @return the parent or <code>null</code> if there's no parent
	 */
	private Object getParent(Object element) {
		if (element instanceof IJavaElement)
			return ((IJavaElement)element).getParent();
		else if (element instanceof IResource)
			return ((IResource)element).getParent();
			
		return null;
	}