From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) by sourceware.org (Postfix) with ESMTP id 44CFB3857835 for ; Tue, 20 Oct 2020 17:02:44 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 44CFB3857835 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-518-IpgBovavOY6G_EjdiQCEPA-1; Tue, 20 Oct 2020 13:02:42 -0400 X-MC-Unique: IpgBovavOY6G_EjdiQCEPA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 21F3F186DD20; Tue, 20 Oct 2020 17:02:41 +0000 (UTC) Received: from localhost (unknown [10.33.36.242]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9A0DF10013D0; Tue, 20 Oct 2020 17:02:40 +0000 (UTC) Date: Tue, 20 Oct 2020 18:02:39 +0100 From: Jonathan Wakely To: Patrick Palka Cc: gcc-patches@gcc.gnu.org, libstdc++@gcc.gnu.org Subject: Re: [PATCH] libstdc++: Fix division by zero in std::sample Message-ID: <20201020170239.GA954627@redhat.com> References: <20200919010804.3509832-1-ppalka@redhat.com> <20200919010804.3509832-2-ppalka@redhat.com> <20200921150134.GE449323@redhat.com> MIME-Version: 1.0 In-Reply-To: <20200921150134.GE449323@redhat.com> X-Clacks-Overhead: GNU Terry Pratchett X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline X-Spam-Status: No, score=-8.2 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H5, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libstdc++@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libstdc++ mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 20 Oct 2020 17:02:45 -0000 On 21/09/20 16:01 +0100, Jonathan Wakely wrote: >On 18/09/20 21:08 -0400, Patrick Palka via Libstdc++ wrote: >>This fixes a division by zero in the selection-sampling std::__search >>overload when the input range is empty (and hence __unsampled_sz is 0). >> >>Tested on x86_64-pc-linux-gnu. >> >>libstdc++-v3/ChangeLog: >> >> * include/bits/stl_algo.h (__sample): Exit early when the >> input range is empty. >> * testsuite/25_algorithms/sample/3.cc: New test. >>--- >>libstdc++-v3/include/bits/stl_algo.h | 3 ++ >>.../testsuite/25_algorithms/sample/3.cc | 50 +++++++++++++++++++ >>2 files changed, 53 insertions(+) >>create mode 100644 libstdc++-v3/testsuite/25_algorithms/sample/3.cc > >OK, thanks. Could you please backport this to all branches too.