Re: [PATCH] evaluate: print error for null string befort assert statement

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Mon, Nov 27, 2017 at 11:48:03PM +0100, Florian Westphal wrote:
> Pablo Neira Ayuso <pablo@netfilter.org> wrote:
> > On Thu, Nov 23, 2017 at 10:25:51PM +0100, Florian Westphal wrote:
> > > Harsha Sharma <harshasharmaiitr@gmail.com> wrote:
> > > > Print error "Null string is not allowed" before assert statement.
> > > > For e.g.
> > > > nft add rule filter input meta iifname '""'
> > > > Error: Null String is not allowed
> > > > add rule filter input meta iifname ""
> > > 
> > > Is there any case where "" should be allowed?
> > > 
> > > If not, I'd rather change scanner.l to not recognize "" as
> > > a quoted string.
> > 
> > We'll get error reporting like this if we handle this from the
> > scanner:
> > 
> > # nft add rule x y ct label \"\"
> > Error: syntax error, unexpected junk
> > add rule x y ct label ""
> 
> Right, we'd have to add dummy empty_string rule to avoid this.
> 
> > This is just two extra lines in the validation step and it is not
> > worth to optimize an error case, ie. do it earlier. So I'm feeling
> > inclined to take this one.
> 
> Makes sense to me.
> 
> > I will mangle the error message to "Empty string is not allowed".
> > "Null" probably sounds too programmer thing.
> 
> Can you also get rid of the assert(strlen ... line?
> Its useless after this patch.

Indeed, done!