Bug 102150 RCP splashscreen stays forever in case of error
If a serious error occurs during the startup of an RCP application, like a missing plugin etc. so that the application could not start, the splash screen of the application stays for ever. This happens if the application is started by PDE using the "Run as eclipse application" menu, but the process has been stopped using the "Stop" button. I had to kill the new eclipse.exe process using the windows taskmanager.
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/Command.java
private IParameter[] parameters = null;
	/**
	 * Constructs a new instance of <code>Command</code> based on the given
	 * identifier. When a command is first constructed, it is undefined.
	 * Commands should only be constructed by the <code>CommandManager</code>
	 * to ensure that the identifier remains unique.
	 * 
	 * @param id
	 *            The identifier for the command. This value must not be
	 *            <code>null</code>, and must be unique amongst all commands.
	 */
	Command(final String id) {
		super(id);
	}
	/**
	 * Adds a listener to this command that will be notified when this command's
	 * state changes.
	 * 
	 * @param commandListener
	 *            The listener to be added; must not be <code>null</code>.
	 */
	public final void addCommandListener(final ICommandListener commandListener) {
		if (commandListener == null) {
			throw new NullPointerException("Cannot add a null command listener"); 
		}
		if (commandListeners == null) {
			commandListeners = new ArrayList(1);
		} else if (commandListeners.contains(commandListener)) {
			return;
		}