Re: Risky local variable mechanism

[Richard M. Stallman]

    Yes, something like that.  Except that it's the list of values that *the
    user* has deemed safe (there'd also be a corresponding alist of values the
    user has deemed undesirable).

    The maintainers/authors wouldn't touch this list.  Instead they'd set
    special properties on the variable's symbol, which would either be t (to say
    that any value is safe) or a predicate which checks a candidate value
    for safety.

That sounds like a good plan to me.