From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-1.mimecast.com (us-smtp-delivery-1.mimecast.com [207.211.31.120]) by sourceware.org (Postfix) with ESMTP id 0D9CD3857C5B for ; Mon, 21 Sep 2020 15:01:39 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 0D9CD3857C5B 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-533-vIM1_uvbOx6BUWZrYAnNHw-1; Mon, 21 Sep 2020 11:01:36 -0400 X-MC-Unique: vIM1_uvbOx6BUWZrYAnNHw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D92BE81A3FF; Mon, 21 Sep 2020 15:01:35 +0000 (UTC) Received: from localhost (unknown [10.33.36.46]) by smtp.corp.redhat.com (Postfix) with ESMTP id 61B9A5D9CD; Mon, 21 Sep 2020 15:01:34 +0000 (UTC) Date: Mon, 21 Sep 2020 16:01:34 +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: <20200921150134.GE449323@redhat.com> References: <20200919010804.3509832-1-ppalka@redhat.com> <20200919010804.3509832-2-ppalka@redhat.com> MIME-Version: 1.0 In-Reply-To: <20200919010804.3509832-2-ppalka@redhat.com> X-Clacks-Overhead: GNU Terry Pratchett X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 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=-9.3 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_NONE, 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: Mon, 21 Sep 2020 15:01:40 -0000 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.