[platform-ui-dev] How to avoid single entry submenus?

[Andre Weinand <weinand@xxxxxxx>]

Both the Compare and VCM plugins use the object contribution mechanism to add
the 'Compare With' & 'Replace With' sub menus to the context menu.

This works great as long as there are at least two items in a submenu.
However, in the Java editor's outliner the submenus happen to have 
only a single entry
which makes them look silly.

Is there a way to have something like an 'optional submenu' that exists only if
it contains more than one entry?

Thanks,
--andre