Pop-up menu non-leaf selection

[cfry@harlequin.com (Christopher Fry)]

I've got a pop up menu with heirarchical menus.
I'd like to have an action run when the user releases the
mouse while it is over the title of a hierarchical menu.

It appears to me now like there's only machinery for
an action to be run when you release the mouse on the leaf
of the heirarchical tree, not at some node in the middle.

I've tried to give pop-up-menus a dialog-item-action as
well as mixed in menu-item and give it a menu-item-action.
These both failed.

I've looked carefully at the menu-select method in
library;pop-up-menu.lisp.
At its core, it calls: #_PopUpMenuSelect .
By experimentation, when I release the mouse over the title
of a heirarchical menu, this trap returns 0 
[same as if they release outside the menu completely] and hence I
can't find out WHICH heirarchical menu the user chose.

Advice greatly appreciated.


CFry