make defcustom automatically mark some variables as safe

make defcustom automatically mark some variables as safe

[Glenn Morris]

What do people think of the idea of changing defcustom to give
some variable types a safe-local-variable property by default?

I mean that, eg, defcustom'ing a variable of :type integer would do:
(put 'variable 'safe-local-variable 'integerp)

Similarly for :type boolean (booleanp), string and regexp (stringp),
and others where it makes sense.

Re: make defcustom automatically mark some variables as safe

[Stefan Monnier]

> What do people think of the idea of changing defcustom to give
> some variable types a safe-local-variable property by default?

> I mean that, eg, defcustom'ing a variable of :type integer would do:
> (put 'variable 'safe-local-variable 'integerp)

> Similarly for :type boolean (booleanp), string and regexp (stringp),
> and others where it makes sense.

I think this is wrong: one of the main changes in Emacs-22 w.r.t file-local
variables is that we made them safe: from no on, a file-local variable
should never be blindly accepted if we're not "sure" that it's safe.

So this would be a step backward since it would usually make good decisions
but not always (e.g. `enable-local-eval' could very well have been defined
with `:type boolean') so that would introduce security holes until someone
notices them.


        Stefan

Re: make defcustom automatically mark some variables as safe

[Glenn Morris]

Stefan Monnier wrote:

> So this would be a step backward since it would usually make good decisions
> but not always (e.g. `enable-local-eval' could very well have been defined
> with `:type boolean') so that would introduce security holes until someone
> notices them.

Ouch. It was a stupid suggestion, forget it.

Re: make defcustom automatically mark some variables as safe

[Richard Stallman]

    What do people think of the idea of changing defcustom to give
    some variable types a safe-local-variable property by default?

    I mean that, eg, defcustom'ing a variable of :type integer would do:
    (put 'variable 'safe-local-variable 'integerp)

It is dangerous.  We want people to think about each variable,
so we don't want any feature that would encourage people not to.