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
public void update(Object[] elements, String[] properties) {
		boolean previousValue = refreshOccurred;
		refreshOccurred = false;
		try {
			for (int i = 0; i < elements.length; ++i) {
				update(elements[i], properties);
				if (refreshOccurred) {
					return;
				}
			}
		} finally {
			refreshOccurred = previousValue;
		}
	}
	/**
	 * Updates the given element's presentation when one or more of its
	 * properties changes. Only the given element is updated.
	 * <p>
	 * This does not handle structural changes (e.g. addition or removal of
	 * elements), and does not update any other related elements (e.g. child
	 * elements). To handle structural changes, use the <code>refresh</code>
	 * methods instead.
	 * </p>
	 * <p>
	 * This should be called when an element has changed in the model, in order
	 * to have the viewer accurately reflect the model. This method only affects
	 * the viewer, not the model.
	 * </p>
	 * <p>
	 * Specifying which properties are affected may allow the viewer to optimize