From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <zsh-workers-return-34181-mason-zsh=primenet.com.au@zsh.org>
Received: (qmail 25834 invoked by alias); 9 Jan 2015 13:26:20 -0000
Mailing-List: contact zsh-workers-help@zsh.org; run by ezmlm
Precedence: bulk
X-No-Archive: yes
List-Id: Zsh Workers List <zsh-workers.zsh.org>
List-Post: <mailto:zsh-workers@zsh.org>
List-Help: <mailto:zsh-workers-help@zsh.org>
X-Seq: 34181
Received: (qmail 4184 invoked from network); 9 Jan 2015 13:26:18 -0000
X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on f.primenet.com.au
X-Spam-Level: 
X-Spam-Status: No, score=-2.7 required=5.0 tests=BAYES_00,DKIM_SIGNED,
	DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW autolearn=ham
	version=3.3.2
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=gmail.com; s=20120113;
        h=mime-version:date:message-id:subject:from:to:content-type;
        bh=XOGF0Mpqgv3K8q6UfirgOkmfzaPjQj8ABkUyH/tSfeM=;
        b=1KTmhZzQTRMGPS/3ulfLWdMMoCNb5ZufZb8dnqv2uooojuBeRgQeIXw/lobsChLgof
         F3lU+H6QY/QSyars7EB9SrbBy9e7U9JI1JPuRNOWSt3rlR6fC9e4w3H80Mk2DEoHlDqE
         jDLKRgMVZ36shxA0o5HGvSUXnKHXQForO5UHoMg22HfHnJa/jeYhyJvVYHvwG9Keb7eN
         C88wpQDQrFXj1og7RLs7+cmXB/ulCoZzaZhdbs99bGiaFejSwRvT9xXaypa1ZTlgcaB0
         AnMv95sV8qbu5wFzK3NGamDXdUAi/NUqlgFRv0GtcR8NKqW1PjMBRZOgkFnUnMBjp2wG
         4Png==
MIME-Version: 1.0
X-Received: by 10.42.38.9 with SMTP id a9mr12770979ice.68.1420809972852; Fri,
 09 Jan 2015 05:26:12 -0800 (PST)
Date: Fri, 9 Jan 2015 14:26:12 +0100
Message-ID: <CAHYJk3TaSOSdKqaJez4nWW7C5zwP7OTdbKP4qD4z7bVJGAsvOg@mail.gmail.com>
Subject: Crash when exporting scalar without value and getsparam fails
From: Mikael Magnusson <mikachu@gmail.com>
To: zsh workers <zsh-workers@zsh.org>
Content-Type: text/plain; charset=UTF-8

2086                if (!(pm->node.flags & PM_UNSET) && !pm->env && !value)

30. returned_null: getsparam returns null (checked 46 out of 57
times). [show details]

CID 439066 (#1 of 1): Dereference null return value (NULL_RETURNS)31.
dereference: Dereferencing a pointer that might be null
getsparam(pname) when calling addenv. [show details]
2087                    addenv(pm, getsparam(pname));


The issue has this comment by Oliver on it, but I couldn't find any
thread about it with a cursory search, so I'm repeating it here;

Comment:

The line of code occurs when you export an existing scalar variable
without giving a new value. It isn't easy to find ways of making
getsparam to fail but I've found one which is enough to declare this a
bug:
 unset IFS
 export IFS
memory allocation failing, such as dupstring would also do the job.
Arguably these cases need fixing but the code highlighted here should
perhaps default to adding the variable to the environment with an
empty value.


and sure enough,
zsh: segmentation fault (core dumped)  zsh -fc 'unset IFS; export IFS'

Would the non-gnu equivalent of addenv(pm, getsparam(pname) ?: ""); do
the trick here? Or should it just return with an error? I guess if we
do the former, then the environment would get out of sync with the
internal parameter value.

-- 
Mikael Magnusson