From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii <eliz@gnu.org> Newsgroups: gmane.emacs.bugs Subject: bug#66764: 29.1; Emacs scrolls for "(goto-char (point-max))" instead of jumping Date: Fri, 27 Oct 2023 09:50:33 +0300 Message-ID: <831qdgftja.fsf@gnu.org> References: <ddf1fc8b-2e31-4b2e-8da6-845031ac4171@gmail.com> <83jzr9fdh0.fsf@gnu.org> <807a1bd5-6477-cc36-088f-efcb782ccb99@gmail.com> <83a5s4fwih.fsf@gnu.org> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="40861"; mail-complaints-to="usenet@ciao.gmane.io" Cc: Gregory Heytings <gregory@heytings.org>, 66764@debbugs.gnu.org To: geza.herman@gmail.com Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Fri Oct 27 08:52:04 2023 Return-path: <bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org> 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 <bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org>) id 1qwGhQ-000APJ-2z for geb-bug-gnu-emacs@m.gmane-mx.org; 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Fri, 27 Oct 2023 06:52:02 +0000 Original-Received: (at 66764) by debbugs.gnu.org; 27 Oct 2023 06:51:04 +0000 Original-Received: from localhost ([127.0.0.1]:34975 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from <debbugs-submit-bounces@debbugs.gnu.org>) id 1qwGgR-0004he-JH for submit@debbugs.gnu.org; Fri, 27 Oct 2023 02:51:03 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:58970) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from <eliz@gnu.org>) id 1qwGgO-0004h4-0x for 66764@debbugs.gnu.org; Fri, 27 Oct 2023 02:51:02 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from <eliz@gnu.org>) id 1qwGfn-0007le-3M; Fri, 27 Oct 2023 02:50:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=References:Subject:In-Reply-To:To:From:Date: mime-version; bh=WOZOTrwFGWhfXTb1H+6/ukEjiOdRHS6sNUu2ElQvj3k=; b=Us04dfUhy6Es AsvWahYb0bgGCviToiZSvMiVlgWR32cCnuZUC2VNEkqA80u96CnV4zilBTGXNkOdgdVT5PHoYfKRA upVoSf5TU+Jrlg8N7STyVvIsf6rpl+lx7E3PrYKFulU6sckPtIPwyDZbIxVZ4QPvgyqAw+LqFotly GkV9HNX7x1H6Hp17in2AYUL/tznnZL7MFjWXSO9oPeaE5R2KB9oRBxx/2AS7gR4LV4Gqtj24cvVWm Q2DKi/S15cPrLdv+YH2AvV416Y+y5GgKkYF0oBO2IEDJC6VFPiQmkJfhtg3Ub8jVTdbLXsX1fmaYi SxhsRh7q3FWvNt+B3QRoQw==; In-Reply-To: <83a5s4fwih.fsf@gnu.org> (message from Eli Zaretskii on Fri, 27 Oct 2023 08:46:14 +0300) 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" <bug-gnu-emacs.gnu.org> List-Unsubscribe: <https://lists.gnu.org/mailman/options/bug-gnu-emacs>, <mailto:bug-gnu-emacs-request@gnu.org?subject=unsubscribe> List-Archive: <https://lists.gnu.org/archive/html/bug-gnu-emacs> List-Post: <mailto:bug-gnu-emacs@gnu.org> List-Help: <mailto:bug-gnu-emacs-request@gnu.org?subject=help> List-Subscribe: <https://lists.gnu.org/mailman/listinfo/bug-gnu-emacs>, <mailto:bug-gnu-emacs-request@gnu.org?subject=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:273341 Archived-At: <http://permalink.gmane.org/gmane.emacs.bugs/273341> OK, I think I see the root cause of the problem: it's your font-lock-keywords setting, viz.: (font-lock-add-keywords nil '(((lambda (bound)) (1 'error prepend t))) t) Without this setting, everything works as expected, and goto-char goes to the EOB almost instantaneously, even when scroll-conservatively is set to a large value. AFAIU, the font-lock-keywords setting above causes the display engine to call this function every time it moves across some chunk of text, which slows down redisplay. This shows with scroll-conservatively set to a large value because Emacs then attempts to find the minimum amount of scrolling the screen in order to bring point into the view. It is a known fact that modes which use advanced font-lock settings should adapt to the long-line situation (when the function long-line-optimizations-p returns non-nil), so I think you should modify your font-lock settings to avoid this problem in that case. CC'ing Gregory in case I missed something in this scenario.