Bug 242427 [Commands] IAction.AS_RADIO_BUTTON actions contributed with ActionContributionItem to MenuManager have problems getting checked on selection
bundles/org.eclipse.jface/src/org/eclipse/jface/action/ActionContributionItem.java
}
	/**
	 * Handles a property change event on the action (forwarded by nested
	 * listener).
	 */
	private void actionPropertyChange(final PropertyChangeEvent e) {
		
		if (isVisible() && widget != null) {
			Display display = widget.getDisplay();
			if (display.getThread() == Thread.currentThread()) {
				update(e.getProperty());
			} else {
				display.asyncExec(new Runnable() {
					public void run() {
						update(e.getProperty());
					}
				});
			}
		}
	}
	/**
	 * Compares this action contribution item with another object. Two action
	 * contribution items are equal if they refer to the identical Action.
	 */
	public boolean equals(Object o) {
		if (!(o instanceof ActionContributionItem)) {
			return false;
		}
		return action.equals(((ActionContributionItem) o).action);
	}