From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Mattias =?UTF-8?Q?Engdeg=C3=A5rd?= Newsgroups: gmane.emacs.bugs Subject: bug#64128: regexp parser zero-width assertion bugs Date: Mon, 19 Jun 2023 10:44:04 +0200 Message-ID: References: <4A303177-384E-4FEF-98F2-FAB89A12ACC9@gmail.com> <83pm5tpdy2.fsf@gnu.org> Mime-Version: 1.0 (Mac OS X Mail 14.0 \(3654.120.0.1.15\)) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="25238"; mail-complaints-to="usenet@ciao.gmane.io" Cc: Eli Zaretskii , Paul Eggert , 64128@debbugs.gnu.org To: Stefan Monnier Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Mon Jun 19 10:45:21 2023 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1qBAVl-0006Lp-42 for geb-bug-gnu-emacs@m.gmane-mx.org; Mon, 19 Jun 2023 10:45:21 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qBAVU-0008Rf-QI; Mon, 19 Jun 2023 04:45:04 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qBAVS-0008RJ-Rp for bug-gnu-emacs@gnu.org; Mon, 19 Jun 2023 04:45:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1qBAVS-0001Fu-Hi for bug-gnu-emacs@gnu.org; Mon, 19 Jun 2023 04:45:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1qBAVS-0002P1-1z for bug-gnu-emacs@gnu.org; Mon, 19 Jun 2023 04:45:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Mattias =?UTF-8?Q?Engdeg=C3=A5rd?= Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Mon, 19 Jun 2023 08:45:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 64128 X-GNU-PR-Package: emacs Original-Received: via spool by 64128-submit@debbugs.gnu.org id=B64128.16871642559152 (code B ref 64128); Mon, 19 Jun 2023 08:45:02 +0000 Original-Received: (at 64128) by debbugs.gnu.org; 19 Jun 2023 08:44:15 +0000 Original-Received: from localhost ([127.0.0.1]:55490 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1qBAUh-0002NX-36 for submit@debbugs.gnu.org; Mon, 19 Jun 2023 04:44:15 -0400 Original-Received: from mail-lf1-f51.google.com ([209.85.167.51]:59741) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1qBAUe-0002NA-U8 for 64128@debbugs.gnu.org; Mon, 19 Jun 2023 04:44:13 -0400 Original-Received: by mail-lf1-f51.google.com with SMTP id 2adb3069b0e04-4f86e1bdce5so1179533e87.3 for <64128@debbugs.gnu.org>; Mon, 19 Jun 2023 01:44:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1687164246; x=1689756246; h=to:references:message-id:content-transfer-encoding:cc:date :in-reply-to:from:subject:mime-version:sender:from:to:cc:subject :date:message-id:reply-to; bh=CJobdB4JqEb22jYmkRHjNqmlmZavTxNLp+PwY/VTfoY=; b=fhAPYXi+9oXrGwNwUqAmK/fM6Tcz+Iz2PhzyYOHAnlnaTKKtSmcDJHR3YLZlKDypDw 9xWa7JgtNcYin7rYGu4ieqCA8fZUgkDw1wx4ZaV39lTZOHobrGvBWAyHXCVePPscUvLO G4ks/ySp5G49zz9IDJY+tTk6ZsGJAECvKGSUt+oKMOULeuty6ZnYDSqbpcEJhZomxz+9 oxaKmkTs4IsoEQTfTMCYN8Tzb44BqwSlgw+CAfuv36SQuYPzac8Lqnc7oWmayNEOSsOE R3HgOPi1K1Gb5pMAkvG0qDP8iH8dBZnVEK4fkBmkgqLW29lRsrYMHKd+U3/VB2swjJWs A6MQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687164246; x=1689756246; h=to:references:message-id:content-transfer-encoding:cc:date :in-reply-to:from:subject:mime-version:sender:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=CJobdB4JqEb22jYmkRHjNqmlmZavTxNLp+PwY/VTfoY=; b=TiDN4PJ4SDfJxmXraOmEsTP4yp5ilBVouc9SszlL0vyOa8qEXiih9/UNA4xHZNq9Mt ZPzbu8zvE3dcDyehhTXzBc7LrBMYRnpYQmbvwtHFhpynqwtA96duPK7jWLHyndm8wqRU JT8ZikCxtee4bnn2dIVC7xvKw4p3vhyPAFo8zrNAKT3LPfvclmnuUcTh5xVK1wI7taXt 8QUQdqJIYof5JZjCl2OXyKdi8g7OMovzGy5iKphgSd2I7jXJjh3TPFlwsKrUR/ZUiAqv Xdd5zF/EOipLs/NL/4miVbno9Dw92pU62QUVYl8ddhuRvGzKQA7mY6Y/TH4/XUKm2XW1 /4BQ== X-Gm-Message-State: AC+VfDx3a69lXKH8h7O8s5Wz64lRX83vglMsOwQ7yqU+us62yyKYWSgg fRKpbRccp30hIu8Wm4CVaPY= X-Google-Smtp-Source: ACHHUZ5amvoXXo1ba5YY47YiZwTvnri6Pjs7BpOMQj9yp2xdmhkbTJPOSOJyPe5sOgNn1kt31KX9yA== X-Received: by 2002:a19:9209:0:b0:4f8:6fe9:3c9c with SMTP id u9-20020a199209000000b004f86fe93c9cmr1120587lfd.49.1687164246271; Mon, 19 Jun 2023 01:44:06 -0700 (PDT) Original-Received: from smtpclient.apple (c188-150-165-235.bredband.tele2.se. [188.150.165.235]) by smtp.gmail.com with ESMTPSA id v11-20020a056512096b00b004f64582a6e6sm4189246lft.207.2023.06.19.01.44.05 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 19 Jun 2023 01:44:05 -0700 (PDT) In-Reply-To: X-Mailer: Apple Mail (2.3654.120.0.1.15) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.bugs:263672 Archived-At: 19 juni 2023 kl. 05.04 skrev Stefan Monnier : > `^` is only special if it's at the beginning of a group, so `^*` will > always treat this * as a literal, right? > "Similarly" `$` is only special if it's at the end of a group, so `$*` = will > always be a repetition of the $ character no? Yes, ^ and $ have additional rules for when they are plain literals and = not subject to these bugs at all. The literal-splitting powers of ^ have now (075e77ac44) been removed. > So the remaining problematic elements are \` \' \b and \B \`* has been observed, so we probably need to keep that working as well. > I suspect if we don't want to signal errors, the next best thing is to > treat them like group B. Yes, maybe; they are less likely to be followed by an operator-literal, = but it would also be good to have all zero-width assertions work the = same way. On the other hand, it can't be worse than we have now, as long as we get = rid of the "quack,\\b*" semantics.