From mboxrd@z Thu Jan  1 00:00:00 1970
From: Bernhard Bitsch <Bernhard.Bitsch@gmx.de>
To: development@lists.ipfire.org
Subject: Aw: Re: [PATCH 2/3] network-functions.pl : Compare correct variables
 in network_equal
Date: Mon, 06 Jan 2020 18:33:05 +0100
Message-ID:
 <trinity-df4034a9-c9fc-41fe-bfe9-e1740dd9b600-1578331985699@3c-app-gmx-bap41>
In-Reply-To: <370BAEAB-C60F-4786-8645-B2BC0D1C8827@ipfire.org>
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="===============2620600953788629482=="
List-Id: <development.lists.ipfire.org>

--===============2620600953788629482==
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: quoted-printable



> Gesendet: Montag, 06. Januar 2020 um 18:16 Uhr
> Von: "Michael Tremer" <michael.tremer(a)ipfire.org>
> An: "Tim FitzGeorge" <ipfr(a)tfitzgeorge.me.uk>
> Cc: development(a)lists.ipfire.org
> Betreff: Re: [PATCH 2/3] network-functions.pl : Compare correct variables i=
n network_equal
>
> Okay.
>=20
> Did I say that I hate Perl?
>=20
> I suppose if you tested this, it works. And it must have worked at some poi=
nt before, because there was a test suite.
>=20

Not a testsuite, but formal verification with the language definition ( which=
 is huge in case of Perl ;) ) proves the correctness in this special case.
SCNR

-Bernhard

> Acked-by: Michael Tremer <michael.tremer(a)ipfire.org>
>=20
> -Michael
>=20
> > On 28 Dec 2019, at 20:57, Tim FitzGeorge <ipfr(a)tfitzgeorge.me.uk> wrote:
> >=20
> > Hello,
> >=20
> > On 24/12/2019 13:04, Michael Tremer wrote:
> >> Hello,
> >>=20
> >> I am still not sure what you are trying to solve here.
> >>=20
> >> &network2bin() has two possible return values:
> >>=20
> >> 1) An array with two values
> >>=20
> >> Or
> >>=20
> >> 2) Undefined
> >=20
> > No. It's called in array context so the return value in the latter case
> > is the list ( undef ).
> >=20
> >>=20
> >> You are now checking if you have an array with any length but two, but t=
his won=E2=80=99t work for undefined. That should at least print a warning th=
at you are trying to determine the length of an undefined array.
> >>=20
> >> So why is this change needed?
> >=20
> > Partly because the return value is an array and partly because the
> > original code checked the scalar variables $bin1 and $bin2 rather than
> > the arrays @bin1 and @bin2 containing the return values; since these
> > scalars aren't used anywhere, network_equal() always returned undef,
> > which is actually the root cause of my original problem.
> >=20
> > Tim
> >=20
> >>=20
> >> -Michael
> >>=20
> >>> On 24 Dec 2019, at 13:56, Tim FitzGeorge <ipfr(a)tfitzgeorge.me.uk> wro=
te:
> >>>=20
> >>> Check result of network2bin is correct rather than checking non-existent
> >>> variable.
> >>>=20
> >>> Signed-off-by: Tim FitzGeorge <ipfr(a)tfitzgeorge.me.uk>
> >>> ---
> >>> config/cfgroot/network-functions.pl | 2 +-
> >>> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>>=20
> >>> diff --git a/config/cfgroot/network-functions.pl b/config/cfgroot/netwo=
rk-functions.pl
> >>> index 56b4bceb7..a3f574760 100644
> >>> --- a/config/cfgroot/network-functions.pl
> >>> +++ b/config/cfgroot/network-functions.pl
> >>> @@ -111,7 +111,7 @@ sub network_equal {
> >>> 	my @bin1 =3D &network2bin($network1);
> >>> 	my @bin2 =3D &network2bin($network2);
> >>>=20
> >>> -	if (!defined $bin1 || !defined $bin2) {
> >>> +	if (@bin1 !=3D 2 || @bin2 !=3D 2) {
> >>> 		return undef;
> >>> 	}
> >>>=20
> >>> --=20
> >>> 2.16.4
> >>>=20
> >>=20
> >=20
>=20
>

--===============2620600953788629482==--