Bug 218467 [Undo] Tighten up IUndoableOperation spec and AbstractOperation to discourage/prevent null labels
GMF creates CompositeCommands with null labels. These NPE when shortenText(getOperation().getLabel()) is invoked from update.
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/operations/AbstractOperation.java
public boolean canRedo() {
		return true;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.core.commands.operations.IUndoableOperation#canUndo()
	 *      <p> Default implementation. Subclasses may override this method.
	 *      </p>
	 */
	public boolean canUndo() {
		return true;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.core.commands.operations.IUndoableOperation#dispose()
	 *      <p> Default implementation. Subclasses may override this method.
	 *      </p>
	 */
	public void dispose() {
		
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.core.commands.operations.IUndoableOperation#execute(org.eclipse.core.runtime.IProgressMonitor,
	 *      org.eclipse.core.runtime.IAdaptable)
	 */
	public abstract IStatus execute(IProgressMonitor monitor, IAdaptable info)