From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Lars Ingebrigtsen Newsgroups: gmane.emacs.bugs Subject: bug#35119: 26.1; narrow-to-region loses word-start/symbol-start information at end Date: Wed, 01 Sep 2021 11:08:41 +0200 Message-ID: <87o89cfysm.fsf@gnus.org> References: <87y34r1glv.fsf@gmail.com> <83a7h7e3ex.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="36245"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) Cc: 35119@debbugs.gnu.org To: Sam Halliday Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Wed Sep 01 11:10:16 2021 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 1mLMG8-0009E1-JC for geb-bug-gnu-emacs@m.gmane-mx.org; Wed, 01 Sep 2021 11:10:16 +0200 Original-Received: from localhost ([::1]:56476 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mLMG7-0005lA-Ff for geb-bug-gnu-emacs@m.gmane-mx.org; Wed, 01 Sep 2021 05:10:15 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:55144) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mLMFu-0005kz-9x for bug-gnu-emacs@gnu.org; Wed, 01 Sep 2021 05:10:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:52955) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1mLMFt-000702-Vp for bug-gnu-emacs@gnu.org; Wed, 01 Sep 2021 05:10:01 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1mLMFt-0007vm-M7 for bug-gnu-emacs@gnu.org; Wed, 01 Sep 2021 05:10:01 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Lars Ingebrigtsen Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Wed, 01 Sep 2021 09:10:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 35119 X-GNU-PR-Package: emacs Original-Received: via spool by 35119-submit@debbugs.gnu.org id=B35119.163048734230414 (code B ref 35119); Wed, 01 Sep 2021 09:10:01 +0000 Original-Received: (at 35119) by debbugs.gnu.org; 1 Sep 2021 09:09:02 +0000 Original-Received: from localhost ([127.0.0.1]:36268 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1mLMEr-0007u7-VR for submit@debbugs.gnu.org; Wed, 01 Sep 2021 05:09:02 -0400 Original-Received: from quimby.gnus.org ([95.216.78.240]:58054) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1mLMEm-0007tq-Ub for 35119@debbugs.gnu.org; Wed, 01 Sep 2021 05:08:57 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnus.org; s=20200322; h=Content-Type:MIME-Version:Message-ID:In-Reply-To:Date: References:Subject:Cc:To:From:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=NbU0ddcRC/vaxOPyvBGN9WdICN1bIuDP89PP4n9haXg=; b=F5vJWlFqItuxtaLANLbrIoKuPW +nHfYcgF+FkWh5mubBeFfG9WPKHsHkgaZTiHhA35cYUt8KwMMRaHZkdpds+9ql8/vsLze7i6Q2zVL 2Zm8FDcln9BqtEUfIozQ4VssZRBxD4bwQS5BVmTGW+2xitH2AZl29VggeIQsmJTdGqfg=; Original-Received: from [84.212.220.105] (helo=elva) by quimby.gnus.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1mLMEc-0006Qi-8k; Wed, 01 Sep 2021 11:08:46 +0200 In-Reply-To: (Sam Halliday's message of "Wed, 3 Apr 2019 13:30:40 +0100") 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" Xref: news.gmane.io gmane.emacs.bugs:213157 Archived-At: Sam Halliday writes: > This impacts me in `looking-back'. Here's an interactive snippet to > demonstrate the problem (not minimised to`narrow-to-region'): > > (defun look-for-35119 () > (interactive) > (if (looking-back > (rx (: word-end ":" word-start)) > ;;(rx (: word-end ":")) > (- (point) 1) 't) > (message "hit") > (message "miss"))) > > in emacs-lisp-mode, which defines : as non-word, interactively > evaluate look-for-35119 when the point is just after the colon in this > example text > > wibble:wobble Here's a simpler test case: (with-temp-buffer (emacs-lisp-mode) (insert "wibble:wobble") (goto-char (point-min)) (search-forward ":") (if (looking-back "\\>:\\<" nil t) (message "hit") (message "miss"))) And, indeed, that fails because (re-search-backward "\\(?:\\>:\\<\\)\\=" nil t) fails. There seems to be a general problem with re-search-backward and these zero-length matches (as you said in a later message). Here's the test case: (with-temp-buffer (emacs-lisp-mode) (insert "wibble:wobble") (goto-char (point-min)) (search-forward ":") (if (re-search-backward ":\\<" nil t) (message "hit") (message "miss"))) That is, if we're at the point where this zero-length match should match, it doesn't. This succeeds: (with-temp-buffer (emacs-lisp-mode) (insert "wibble:wobble") (goto-char (point-min)) (search-forward ":") (forward-char 1) (if (re-search-backward ":\\<" nil t) (message "hit") (message "miss"))) -- (domestic pets only, the antidote for overdose, milk.) bloggy blog: http://lars.ingebrigtsen.no