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/StructuredViewer.java
* Adds the element item pair to the element map
 * <p>
 * This method is internal to the framework; subclassers should not call
 * this method.
 * </p>
 *
 * @param element the element
 * @param item the corresponding widget
 */
protected void mapElement(Object element, Widget item) {
	if (elementMap != null)
		elementMap.put(element, item);
}
/**
 * Determines whether a change to the given property of the given element
 * would require refiltering and/or resorting.
 * <p>
 * This method is internal to the framework; subclassers should not call
 * this method.
 * </p>
 *
 * @param element the element
 * @param property the property
 * @return <code>true</code> if refiltering is required, and <code>false</code>
 *   otherwise
 */
protected boolean needsRefilter(Object element, String property) {
	if (sorter != null && sorter.isSorterProperty(element, property))
		return true;
	if (filters != null) {