From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Gregory Heytings via "Emacs development discussions." Newsgroups: gmane.emacs.devel Subject: Re: A solution to display completion candidates after point in a minibuffer Date: Sun, 04 Oct 2020 16:52:10 +0000 Message-ID: References: <83sgavfzno.fsf@gnu.org> <83o8lidkrk.fsf@gnu.org> Reply-To: Gregory Heytings Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset=US-ASCII Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="23837"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Alpine 2.22 (NEB 394 2020-01-19) Cc: monnier@iro.umontreal.ca, emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sun Oct 04 18:59:29 2020 Return-path: Envelope-to: ged-emacs-devel@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 1kP7M9-00067b-JQ for ged-emacs-devel@m.gmane-mx.org; Sun, 04 Oct 2020 18:59:29 +0200 Original-Received: from localhost ([::1]:48334 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kP7M8-00013k-Jg for ged-emacs-devel@m.gmane-mx.org; Sun, 04 Oct 2020 12:59:28 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:34736) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kP7FF-0006Rf-BT for emacs-devel@gnu.org; Sun, 04 Oct 2020 12:52:21 -0400 Original-Received: from mx.sdf.org ([205.166.94.24]:54702) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kP7FB-0000Ar-Rm; Sun, 04 Oct 2020 12:52:20 -0400 Original-Received: from sdf.org (IDENT:ghe@otaku.sdf.org [205.166.94.8]) by mx.sdf.org (8.15.2/8.14.5) with ESMTPS id 094GqDpY017940 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits) verified NO); Sun, 4 Oct 2020 16:52:13 GMT Original-Received: (from ghe@localhost) by sdf.org (8.15.2/8.12.8/Submit) id 094GqWs8024770; Sun, 4 Oct 2020 16:52:32 GMT In-Reply-To: <83o8lidkrk.fsf@gnu.org> Received-SPF: pass client-ip=205.166.94.24; envelope-from=ghe@sdf.org; helo=mx.sdf.org X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/04 12:11:13 X-ACL-Warn: Detected OS = ??? X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:257037 Archived-At: >>>> No, that's not what I meant. In that case redisplay does not scroll >>>> and does not move point. Point simply becomes invisible. >>> >>> No, redisplay will never accept a result that point is invisible. If >>> it ever does display such situations, it's a bug that needs to be >>> fixed. >> >> Never say never... >> >>>> It becomes visible again after the next redisplay, a second or two >>>> later. >>> >>> If such a situation exists, please describe how to reproduce it, >>> because it's a bug we need to fix. Emacs should never display a >>> window where point is not fully visible. >> >> Here's a recipe: >> >> emacs -Q >> (defun recipe () >> (interactive) >> (set-frame-width nil 80) >> (set-frame-height nil 30) >> (switch-to-buffer (get-buffer-create "*Recipe*")) >> (goto-char 1) >> (let ((i 0)) (while (< i 60) (setq i (1+ i)) (insert (format "L%d\n" i)))) >> (goto-char 148) >> (sit-for 0.25) >> (add-hook 'window-scroll-functions (lambda (&rest args) (set-window-start nil 1))) >> (forward-line 13)) >> M-x recipe >> press C-n > > AFAIU, this is exactly why we say not to use window-scroll-functions for > this purpose. IOW, there is indeed a bug here, and the bug is in the > Lisp code you presented: window-scroll-functions are not meant to be > used to affect redisplay, they are meant to inform Lisp programs about > what redisplay is about to do with a window. > I did not say that there was a bug in redisplay here, I explained what happens, and you said there was a bug, that redisplay should never do this, and asked me to write a recipe, which I did. Obviously, I do not do what I did above, to demonstrate what you said was a bug, in my code.