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 (fMemento != null)	
			fActionSet.restoreFilterAndSorterState(fMemento);
	}
	private void restoreUIState(IMemento memento) {
		restoreExpansionState(memento);
		restoreSelectionState(memento);
		
		
	}
	private void restoreLinkingEnabled(IMemento memento) {
		Integer val= memento.getInteger(PreferenceConstants.LINK_PACKAGES_TO_EDITOR);
		if (val != null) {
			fLinkingEnabled= val.intValue() != 0;
		}
	}
	protected void restoreScrollState(IMemento memento, Tree tree) {
		ScrollBar bar= tree.getVerticalBar();
		if (bar != null) {
			try {
				String posStr= memento.getString(TAG_VERTICAL_POSITION);
				int position;
				position= new Integer(posStr).intValue();
				bar.setSelection(position);
			} catch (NumberFormatException e) {
				
			}
		}
		bar= tree.getHorizontalBar();
		if (bar != null) {
			try {