It should be so already. Code-wise there is no difference between a
menu bar menu and a detached menu, so if enabling/disabling works for
the menu bar, it should work for detached menus also. Are there cases
where this doesn't work?
When a frame is iconified, the detached menus are (or should be)
iconified as well. This is done by the GTK toolkit.
What about the other half of what Richard wrote: ``make the enabling
and disabling of items in the menu depend on its associated frame''
(which is the original problem that started this thread)? When you
say ``it should be so already'', do you mean it already works?
Because, AFAIK, in the current code enabling/disabling menu items
depends on the variable menu-updating-frame, which is not set
correctly on some platforms, like the no-toolkit X build.