buffer-local keymaps

[Roland Winkler]

A proper solution of bug#10254 (a bug in lisp/textmodes/bibtex.el)
requires that bibtex-mode uses not only buffer-local variables but
also buffer-local keymaps (for buffer-local menus). What is the best
way to implement this? Is it possible to define a default keymap for
the buffer-local keymaps similar to the default value of
buffer-local variables? Or is it necessary that every BibTeX buffer
uses a buffer-local keymap that is a child keymap of some default
keymap? (In this context, what is the equivalent of
kill-local-variable?) Or do I better use yet some other approach?

Thanks.

Roland