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
for (int i = 0; i < items.length; i++) {
		Widget item = items[i];
		Object e = item.getData();
		if (e != null)
			list.add(e);
	}
	return list;
}
/**
 * Handles a tree collapse event from the SWT widget.
 *
 * @param event the SWT tree event
 */
protected void handleTreeCollapse(TreeEvent event) {
	if (event.item.getData() != null) {
		fireTreeCollapsed(new TreeExpansionEvent(this, event.item.getData()));
	}
}
/**
 * Handles a tree expand event from the SWT widget.
 *
 * @param event the SWT tree event
 */
protected void handleTreeExpand(TreeEvent event) {
	createChildren(event.item);
	if (event.item.getData() != null) {
		fireTreeExpanded(new TreeExpansionEvent(this, event.item.getData()));
	}
}
/* (non-Javadoc)