Bug 15844 [Exception Handling] SelectionChange events and NPE
Build 20020508 Due to new global actions there are now more objects listening to selection changes send out by a JFace viewer. We now had the case that one of the listener generated a NPE. As a result all listeners registered after that one didn't receive the selection change event. StructuredViewers should be more fault tolorant to exceptions when informing listeners.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
* </p>
 *
 * @param parentElement the parent element
 * @param childElements the child elements to add
 */
public void add(Object parentElement, Object[] childElements) {
	Assert.isNotNull(parentElement);
	Assert.isNotNull(childElements);
	Widget widget = findItem(parentElement);
	
	if (widget == null)
		return;
	Control tree = getControl();
	
	
	
	if (widget instanceof Item) {
		Item ti= (Item) widget;
		if (!getExpanded(ti)) {
			boolean needDummy = isExpandable(parentElement);
			boolean haveDummy = false;
			
			Item[] items= getItems(ti);
			for (int i = 0; i < items.length; i++) {
				if (items[i].getData() != null) {
					disassociate(items[i]);
					items[i].dispose();
				}
				else {
					if (needDummy && !haveDummy) {