Bug 41743 [MenuMgmt] IContributionManager.remove has undocumented behavior
build 20030820 The doc for IContributionManager.remove says that null will be returned if "this manager has no contribution items with the given id". When I call remove on a menu with an invalid ID I get an IllegalArgumentException instead of a null return value.
bundles/org.eclipse.jface/src/org/eclipse/jface/action/ContributionManager.java
if (itemId != null && itemId.equalsIgnoreCase(id))
			return i;
	}
	return -1;
}
/**
 * Returns the index of the object in the internal structure. This is different from 
 * <code>indexOf(String id)</code> since some contribution items may not have an id.
 *  
 * @param item the contribution item 
 * @return the index, or -1 if the item is not found
 * @since 3.0
 */
protected int indexOf(IContributionItem item) {
	return contributions.indexOf(item);
}
/**
 * Insert the item at the given index.
 */
public void insert(int index, IContributionItem item) {
	if (index > contributions.size())
		throw new IndexOutOfBoundsException("inserting " + item.getId() + " at " + index); 
	if (allowItem(item)) {
	    item.setParent(this);
	    contributions.add(index, item);
	    itemAdded(item);
	}
}
/* (non-Javadoc)
 * Method declared on IContributionManager.