Bug 31683 Show In doesn't work for class file in rt.jar
I20030611 - create Test project that uses Jar container - open NumberFormat.class - activate Show In... and choose Package Explorer Observe: NumberFormat.class doesn't get revealed.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerPart.java
private int getLayoutAsInt() {
		if (fIsCurrentLayoutFlat)
			return FLAT_LAYOUT;
		else
			return HIERARCHICAL_LAYOUT;
	}
	protected void saveScrollState(IMemento memento, Tree tree) {
		ScrollBar bar= tree.getVerticalBar();
		int position= bar != null ? bar.getSelection() : 0;
		memento.putString(TAG_VERTICAL_POSITION, String.valueOf(position));
		
		bar= tree.getHorizontalBar();
		position= bar != null ? bar.getSelection() : 0;
		memento.putString(TAG_HORIZONTAL_POSITION, String.valueOf(position));
	}
	protected void saveSelectionState(IMemento memento) {
		Object elements[]= ((IStructuredSelection) fViewer.getSelection()).toArray();
		if (elements.length > 0) {
			IMemento selectionMem= memento.createChild(TAG_SELECTION);
			for (int i= 0; i < elements.length; i++) {
				IMemento elementMem= selectionMem.createChild(TAG_ELEMENT);
				
				Object o= elements[i];
				if (o instanceof IJavaElement)
					elementMem.putString(TAG_PATH, ((IJavaElement) elements[i]).getHandleIdentifier());
			}
		}
	}
	protected void saveExpansionState(IMemento memento) {
		Object expandedElements[]= fViewer.getVisibleExpandedElements();