From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS22989 209.51.188.0/24 X-Spam-Status: No, score=-3.9 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, RCVD_IN_DNSWL_HI,RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL,SPF_HELO_PASS, SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id 34A041F8C6 for ; Sat, 17 Jul 2021 02:59:10 +0000 (UTC) Received: from localhost ([::1]:57288 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m4aXk-000334-U5 for normalperson@yhbt.net; Fri, 16 Jul 2021 22:59:08 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:51060) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m4aXh-0002zz-7G for bug-gnulib@gnu.org; Fri, 16 Jul 2021 22:59:05 -0400 Received: from zimbra.cs.ucla.edu ([131.179.128.68]:45556) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m4aXd-00055S-CR for bug-gnulib@gnu.org; Fri, 16 Jul 2021 22:59:04 -0400 Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id E41E21600FB; Fri, 16 Jul 2021 19:58:57 -0700 (PDT) Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id SFx0hP_5H16f; Fri, 16 Jul 2021 19:58:57 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 46AC4160106; Fri, 16 Jul 2021 19:58:57 -0700 (PDT) X-Virus-Scanned: amavisd-new at zimbra.cs.ucla.edu Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id VajERCk35dQX; Fri, 16 Jul 2021 19:58:57 -0700 (PDT) Received: from [192.168.0.205] (ip72-206-1-93.fv.ks.cox.net [72.206.1.93]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id F175E1600FB; Fri, 16 Jul 2021 19:58:56 -0700 (PDT) Subject: Re: possible bug in regex and dfa To: Arnold Robbins , bug-gnulib@gnu.org References: From: Paul Eggert Message-ID: <85ef7fe3-c793-f082-3df1-3011fd8d0966@cs.ucla.edu> Date: Fri, 16 Jul 2021 21:58:56 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Received-SPF: pass client-ip=131.179.128.68; envelope-from=eggert@cs.ucla.edu; helo=zimbra.cs.ucla.edu X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: bug-gnulib@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Gnulib discussion list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnulib-bounces+normalperson=yhbt.net@gnu.org Sender: "bug-gnulib" On 7/15/21 1:48 PM, Arnold Robbins wrote: > The regexp used there, ".^", to my mind should be treated as invalid. No, that regular expression is valid because "." matches newline in POSIX EREs. So the "." matches a newline, and the following "^" matches the start of the next line.