Re: Multiple runs of menu-bar-update-hook

[Richard Stallman]

    Buffer text may have a keymap or local-map property which may define
    specific menu-items (even top-level items) that are specific to that
    buffer position.

    So even just moving point must call the update hook.

Just moving point does not call the hook, so I think we have
implicitly decided that point-specific calculations in
menu-bar-update-hook do not make sense.

I would say that mark-specific calculations also do not make sense there.
In other words, changing the displayed region need not run this hook.
It does so when one buffer appears in multiple windows, because I didn't
try to optimize that case.

    In other words, in general, is the update of the menu bar more appropriate
    for redisplay (which in reality hardly ever needs to actually update the
    menu bar) or for the (small?) set of actions that can effect menu bars?

Creating buffers needs to run it.