Re: Shall menu_bar_items and tool_bar_items look at text property keymaps?

[Richard Stallman]

    Instead of trying to make it work (which will involve a severe performance
    penalty), I suggest to remove the code and document in the Elisp manual
    that those text property maps don't support menu-bar and tool-bar bindings.

Documenting that seems like a good idea.  Is there special code
that attempts to make it work but fails?  If so, put it in #if 0
and with a comment explaining why it doesn't work and why
working correctly is hard.