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
commandListeners.add(commandListener);
	}
	/**
	 * Adds a listener to this command that will be notified when this command
	 * is about to execute.
	 * 
	 * @param executionListener
	 *            The listener to be added; must not be <code>null</code>.
	 */
	public final void addExecutionListener(
			final IExecutionListener executionListener) {
		if (executionListener == null) {
			throw new NullPointerException(
					"Cannot add a null execution listener"); 
		}
		if (executionListeners == null) {
			executionListeners = new ArrayList(1);
		} else if (executionListeners.contains(executionListener)) {
			return;
		}
		executionListeners.add(executionListener);
	}
	/**
	 * <p>
	 * Adds a state to this command. This will add this state to the active
	 * handler, if the active handler is an instance of {@link IObjectWithState}.
	 * </p>
	 * 
	 * @param id
	 *            The identifier of the state to add; must not be