From mboxrd@z Thu Jan  1 00:00:00 1970
From: Michael Tremer <michael.tremer@ipfire.org>
To: development@lists.ipfire.org
Subject: Re: [PATCH 2/3] network-functions.pl : Compare correct variables in
 network_equal
Date: Mon, 06 Jan 2020 18:57:19 +0000
Message-ID: <F02B261F-C197-42A3-BBA2-4B481BFA18B3@ipfire.org>
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Thx.

> On 6 Jan 2020, at 17:33, Bernhard Bitsch <Bernhard.Bitsch(a)gmx.de> wrote:
>=20
>=20
>=20
>> 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 =
in network_equal
>>=20
>> 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 po=
int before, because there was a test suite.
>>=20
>=20
> Not a testsuite, but formal verification with the language definition ( whi=
ch is huge in case of Perl ;) ) proves the correctness in this special case.
> SCNR
>=20
> -Bernhard
>=20
>> 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
>>=20


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