From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 20710 invoked by alias); 14 Jan 2018 12:06:18 -0000 Mailing-List: contact zsh-workers-help@zsh.org; run by ezmlm Precedence: bulk X-No-Archive: yes List-Id: Zsh Workers List List-Post: List-Help: List-Unsubscribe: X-Seq: 42268 Received: (qmail 4654 invoked by uid 1010); 14 Jan 2018 12:06:18 -0000 X-Qmail-Scanner-Diagnostics: from mail-lf0-f45.google.com by f.primenet.com.au (envelope-from , uid 7791) with qmail-scanner-2.11 (clamdscan: 0.99.2/21882. spamassassin: 3.4.1. Clear:RC:0(209.85.215.45):SA:0(-1.9/5.0):. Processed in 2.694342 secs); 14 Jan 2018 12:06:18 -0000 X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on f.primenet.com.au X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL,SPF_PASS,T_DKIM_INVALID autolearn=ham autolearn_force=no version=3.4.1 X-Envelope-From: schaefer@brasslantern.com X-Qmail-Scanner-Mime-Attachments: | X-Qmail-Scanner-Zip-Files: | DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=brasslantern-com.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=nLRogzKp3g9Q06O9Q80OtV8woqp5qBXLdL1UPedDi58=; b=L7plr++nC3gdW9RS+0svaQDGmHF+KFoMzJspE+5eLq0vkBIVNVgAwtVYGZSz28zRKB BFuFa5aG2yKsHh5ZM5TOC7BZJLNg9kPnF1DiC/UH9aVFDmxDULse5BbjeobSh3ZmOqZs hncTroLWO7Vrw1c1HvAL+1sJyTg6ReLHr7MOLomXN2ZUlULyVb5ER4UGjy2O28t8nM2B YeSMMttIWaALsGj4CjGmvmRYtwtjZPq/soUsxfMRYUEbSLWo/YbNrmFq8JVqu06ZTAb5 byPTif7Vxd4lg8g7CiKOzVSESGk2iDvNRdLTuiLvEb4FXpYa4DVEyr/mcYCY1/sm/nau x94w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=nLRogzKp3g9Q06O9Q80OtV8woqp5qBXLdL1UPedDi58=; b=Ku9YqS2yVUxjm3gPGzxBT6C3Ystl48aajq1jXsF9hRJJ41ohSO9EV4bGyQDz03nhCx Kk5vH3pnCkfhFM24zn3smONXnMwEPr0lHaOoZzqeM6hQLwEGqYnhZfPjIIxwYdzTOu5o /F9WiN2zSFACg7zzhI+cXTK9Yyr0eXWrrZZOq4gMpRxjK9MHU6nbnS0MmmSA+m3lk+Id CR+42lHU/9oIABPPBA7MyH8qaCFW+JWt1zVhwDpPYiAn+N5r652isNucdSkmjJpLc3+y nki8+7OkjOiFqrnjP38XZ/nMwuEPJqwPfK5S8ErcYkByAaB8cDYpFKH42SUhTvZgY3df vlDw== X-Gm-Message-State: AKwxytdxO5Jwmu4S//WQXd5DRUHnZRYMXrJxOa3ORfpcEBBzekYqLnci lKoUf7+XjLtdrQ439itgAKN3qWT9BvPVkgvWveSHY4s2 X-Google-Smtp-Source: ACJfBovKbEaseL+ePdCFbgQ9koW/N/Neiy47VUnPgxgTRWA61yPMh/S+XaoHH2CQNqVhvOmafryQXxu/4X38SInW/78= X-Received: by 10.25.181.155 with SMTP id g27mr10021543lfk.47.1515931570251; Sun, 14 Jan 2018 04:06:10 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20180114060557.hmrvpg6t4rdebgv6@gmail.com> References: <20180114060557.hmrvpg6t4rdebgv6@gmail.com> From: Bart Schaefer Date: Sun, 14 Jan 2018 04:06:09 -0800 Message-ID: Subject: Re: [PATCH] jp: fix segfaults during parameter expansion To: "zsh-workers@zsh.org" Content-Type: text/plain; charset="UTF-8" On Sat, Jan 13, 2018 at 10:05 PM, Joey Pabalinas wrote: > Running `zsh -fc ': ${${(PAA)p[foo]}::=x}'` in current zsh versions causes: > >> "segmentation fault (core dumped) zsh -fc '(: ${${(PAA)p[foo]}::=x})' > > Add checks to catch NULL dereferences. Thanks for tracking this down. Defensive programming is always good, but I think this is indicative of a problem further upstream. What's the expected output of that substitution? The following prevents the segfault for me, instead giving the error "zsh: not an identifier: " (i.e., empty string is not a valid parameter name). But perhaps there's a different error that should occur here if val is NULL? diff --git a/Src/subst.c b/Src/subst.c index d027e3d..73491c2 100644 --- a/Src/subst.c +++ b/Src/subst.c @@ -2430,7 +2430,10 @@ paramsubst(LinkList l, LinkNode n, char **str, int qt, int pf_flags, val = aval[0]; isarr = 0; } - s = dyncat(val, s); + if (val) + s = dyncat(val, s); + else + s = dupstring(s); /* Now behave po-faced as if it was always like that... */ subexp = 0; /*