bug#37507: 26.3; Non-number value for `fill-column' causes wrong-type-arg error for `C-h f'

[Stefan Kangas <stefan@marxist.se>]

tags 37507 + notabug
close 37507
quit

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Noam Postavsky <npostavs@gmail.com>
>> Date: Tue, 24 Sep 2019 15:53:15 -0400
>> Cc: 37507@debbugs.gnu.org
>>
>> Drew Adams <drew.adams@oracle.com> writes:
>>
>> > `fill-column' is supposed to have an integer value > 0.
>> >
>> > But if it has a non-numeric value then other functions can barf, unless
>> > they watch out for that.
>>
>> Shouldn't users just not set it to a non-numeric value then?  I'm sure
>> you can cause all sort of errors by setting things to invalid values.
>>
>> > emacs -Q
>> >
>> > (setq fill-column nil)
>>
>> Do you mean setq-default (otherwise I can't reproduce)?
>
> I agree that this is a cockpit error.  Users who are prone to such
> mistakes should use Customize to set values of variables.  Users who
> use setq-default should know what they are doing.
>
> It is unreasonable to request that we have an explicit test for valid
> values in every place that references a variable.  Our protection is
> that we signal an error, and that should IMO be good enough in cases
> such as this one.
>
> P.S.  This bug report came from a question on Reddit, where it
> received the same responses.

I think the above makes it clear that this is not a bug.  I'm
consequently closing this report.

Best regards,
Stefan Kangas