From 2d124b42a6bfce513a699a33ba9878a22e5d2e2a Mon Sep 17 00:00:00 2001 From: Vladimir Marek Date: Sat, 27 Apr 2013 18:05:40 +0200 Subject: [PATCH] Re: [PATCH] don't store temporary value returned from c_str() --- de/f417b79414509c0c6c51f982e8181487d53427 | 88 +++++++++++++++++++++++ 1 file changed, 88 insertions(+) create mode 100644 de/f417b79414509c0c6c51f982e8181487d53427 diff --git a/de/f417b79414509c0c6c51f982e8181487d53427 b/de/f417b79414509c0c6c51f982e8181487d53427 new file mode 100644 index 000000000..23f67727e --- /dev/null +++ b/de/f417b79414509c0c6c51f982e8181487d53427 @@ -0,0 +1,88 @@ +Return-Path: +X-Original-To: notmuch@notmuchmail.org +Delivered-To: notmuch@notmuchmail.org +Received: from localhost (localhost [127.0.0.1]) + by olra.theworths.org (Postfix) with ESMTP id 93E9F431FBF + for ; Sat, 27 Apr 2013 09:05:49 -0700 (PDT) +X-Virus-Scanned: Debian amavisd-new at olra.theworths.org +X-Spam-Flag: NO +X-Spam-Score: -2.299 +X-Spam-Level: +X-Spam-Status: No, score=-2.299 tagged_above=-999 required=5 + tests=[RCVD_IN_DNSWL_MED=-2.3, UNPARSEABLE_RELAY=0.001] + autolearn=disabled +Received: from olra.theworths.org ([127.0.0.1]) + by localhost (olra.theworths.org [127.0.0.1]) (amavisd-new, port 10024) + with ESMTP id rsB0oxVyYv-d for ; + Sat, 27 Apr 2013 09:05:49 -0700 (PDT) +Received: from aserp1040.oracle.com (aserp1040.oracle.com [141.146.126.69]) + (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) + (No client certificate requested) + by olra.theworths.org (Postfix) with ESMTPS id 449FB431FAE + for ; Sat, 27 Apr 2013 09:05:49 -0700 (PDT) +Received: from acsinet22.oracle.com (acsinet22.oracle.com [141.146.126.238]) + by aserp1040.oracle.com (Sentrion-MTA-4.3.1/Sentrion-MTA-4.3.1) with + ESMTP id r3RG5j9S028392 + (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); + Sat, 27 Apr 2013 16:05:46 GMT +Received: from aserz7021.oracle.com (aserz7021.oracle.com [141.146.126.230]) + by acsinet22.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id + r3RG5iAd008228 + (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL); + Sat, 27 Apr 2013 16:05:45 GMT +Received: from ubhmt108.oracle.com (ubhmt108.oracle.com [156.151.24.13]) + by aserz7021.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id + r3RG5iRx010412; Sat, 27 Apr 2013 16:05:44 GMT +Received: from vi64-x3-2e-prg06.cz.oracle.com (/10.163.102.127) + by default (Oracle Beehive Gateway v4.0) + with ESMTP ; Sat, 27 Apr 2013 09:05:43 -0700 +Date: Sat, 27 Apr 2013 18:05:40 +0200 +From: Vladimir Marek +To: Jani Nikula +Subject: Re: [PATCH] don't store temporary value returned from c_str() +Message-ID: <20130427160540.GB17459@vi64-x3-2e-prg06.cz.oracle.com> +References: <1366405933-17223-1-git-send-email-Vladimir.Marek@oracle.com> + <878v44qhop.fsf@nikula.org> +MIME-Version: 1.0 +Content-Type: text/plain; charset=utf-8 +Content-Disposition: inline +In-Reply-To: <878v44qhop.fsf@nikula.org> +User-Agent: Mutt/ (2012-12-30) +X-Source-IP: acsinet22.oracle.com [141.146.126.238] +Cc: notmuch@notmuchmail.org, Vladimir Marek +X-BeenThere: notmuch@notmuchmail.org +X-Mailman-Version: 2.1.13 +Precedence: list +List-Id: "Use and development of the notmuch mail system." + +List-Unsubscribe: , + +List-Archive: +List-Post: +List-Help: +List-Subscribe: , + +X-List-Received-Date: Sat, 27 Apr 2013 16:05:49 -0000 + +> It's okay to use the result of .c_str() as long as the string object +> stays in scope, and none of the non-const member functions are +> called. Here, I think the problem is that TermIterator's overloaded +> operator*() returns a string object within the if block's scope, and it +> goes immediately out of scope. You could check this by adding + +Right, I overlooked that TermIterator creates temporary string (if I +understand you correctly). + +> +> string s = *i; +> +> in function scope, and replacing (*i) with s in the if block. This might +> also be more obvious than the presented patch, but I think the patch is +> fine too. + +I would prefer my change as it avoids creating another std::string. At +least I think. + +Thank you +-- + Vlad -- 2.26.2