Bug 299438 [CommonNavigator] CNF viewer state non properly reset when NCEs are activated or deactivated
The map of the objects to the NCEs should be reset whenever the NCEs associated with the viewer to change to avoid having stale label information. This has shown up when looking at the CNF tests that change the viewer.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
SafeRunnable.run(new SafeRunnable() {
				public void run() {
					l.selectionChanged(event);
				}
			});
		}
	}
	/**
	 * Returns the comparer to use for comparing elements, or
	 * <code>null</code> if none has been set.  If specified,
	 * the viewer uses this to compare and hash elements rather
	 * than the elements' own equals and hashCode methods.
	 *           
	 * @return the comparer to use for comparing elements or
	 *            <code>null</code>
	 */
	public IElementComparer getComparer() {
		return comparer;
	}
	/**
	 * Returns the filtered array of children of the given element. The
	 * resulting array must not be modified, as it may come directly from the
	 * model's internal state.
	 * 
	 * @param parent
	 *            the parent element
	 * @return a filtered array of child elements
	 */
	protected Object[] getFilteredChildren(Object parent) {
		Object[] result = getRawChildren(parent);