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/CheckboxTreeViewer.java
boolean checked = checkedElements.contains(data);
			if (checked != item.getChecked()) {
				item.setChecked(checked);
			}
		}
		internalSetChecked(checkedElements, item);
	}
}
/**
 * Sets the grayed state of all items to correspond to the given set of grayed elements.
 *
 * @param grayedElements the set (element type: <code>Object</code>) of elements which are grayed
 * @param widget the widget
 */
private void internalSetGrayed(Set grayedElements, Widget widget) {
	Item[] items = getChildren(widget);
	for (int i = 0; i < items.length; i++) {
		TreeItem item = (TreeItem) items[i];
		Object data = item.getData();
		if (data != null) {
			boolean grayed = grayedElements.contains(data);
			if (grayed != item.getGrayed()) {
				item.setGrayed(grayed);
			}
		}
		internalSetGrayed(grayedElements, item);
	}
}
/* (non-Javadoc)
 * Method declared on Viewer.