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
/**
 * Adds a contribution item to the start or end of the group 
 * with the given name.
 *
 * @param groupName the name of the group
 * @param item the contribution item
 * @param append <code>true</code> to add to the end of the group, 
 *   and <code>false</code> to add the beginning of the group
 * @exception IllegalArgumentException if there is no group with
 *   the given name
 */
private void addToGroup(String groupName, IContributionItem item, boolean append) 
{
	int i;
	Iterator items = contributions.iterator();
	for (i = 0; items.hasNext(); i++) {
		IContributionItem o = (IContributionItem) items.next();
		if (o.isGroupMarker()) {
			String id = o.getId();
			if (id != null && id.equalsIgnoreCase(groupName)) {
				i++;
				if (append) {
					for (; items.hasNext(); i++) {
						IContributionItem ci = (IContributionItem) items.next();
						if (ci.isGroupMarker())
							break;
					}
				}
				if (allowItem(item)) {
					item.setParent(this);