Re: The `risky-local-variable' blacklist

[Stefan <monnier@iro.umontreal.ca>]

>> So the "risky" annotation was only added in order to enable potentially
>> dangerous things like "eval" in that variable.

> We may be speaking at cross-purposes, but are you sure about that?

You do not understand.  I was speaking very specifically about the
timeclock-mode-string.  My comments only apply to variables used as
mode-line-string.

> I realize now that my example about timeclock is silly, because
> `timeclock-mode-string' wasn't dangerous before and isn't now, since it
> has never been included in `mode-line-format' except as a symbol, and
> those are not evaluated twice (so as to execute a form set as its value).

I don't think you understand the reason why timeclock-mode-string was not
dangerous before: timeclock-mode-string can have a value of the form
(:eval <foo>) which means "evaluate <foo> to get the string to display".
So there's clearly something dangerous here.  Such evalution-in-mode-string
is new in Emacs-21, so most foo-mode-line-string variable have suddenly been
made dangerous.  Instead of going through all those vars and marking them
risky, Emacs-21 decided that "if the var is not marked `risky', then ignore
any of those new :eval special forms".  I.e. it's safe either way. but in
order to be able to use the new feature, you need to mark the var as
"risky".

I didn't discuss your general point about risky variables (because I mostly
agree with it).


        Stefan