MenuManager.setRemoveAllWhenShown() may encourage resource leaks

[stippi]

The following pattern is often seen in code using MenuManager:

menuManager.setRemoveAllWhenShown(true);
menuManager.addMenuListener(new IMenuListener() {
	@Override
	public void menuAboutToShow(IMenuManager manager) {
		// add stuff to the manager dynamically depending on some state
	}
});

The ContributionItems added in the IMenuListener are removed before the next invocation of menuAboutToShow(), but their dispose() method is not also called. This assumes that Contribution items are created only once, and the instances are re-used between calls to menuAboutToShow(). This was not clear to me at all. I have tons of code which creates MenuManagers on the fly, or directly calls menu.add(actionInstance), which creates an anonymous ActionContributionItem that noone keeps a reference to when it is removed via setRemoveAllWhenShown(true).

If I am not mistaken MenuManager.dispose() and other implementations of IContributionItem.dispose() are written in such a way that the item remains useable. Resources are simply recreated when needed. Either the dispose() hook should be called when removing all items, or at least the documentation should make it very clear that this is what needs to be done by the user of the API.