From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Stefan Monnier via "Bug reports for GNU Emacs, the Swiss army knife of text editors" Newsgroups: gmane.emacs.bugs Subject: bug#63988: 30.0.50; Recent header line format changes cause spin/seg fault with format-mode-line Date: Sat, 10 Jun 2023 12:16:45 -0400 Message-ID: References: <831qij24qm.fsf@gnu.org> <83wn0bzoeb.fsf@gnu.org> Reply-To: Stefan Monnier Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="23397"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Cc: Eshel Yaron , 63988@debbugs.gnu.org, aaronjensen@gmail.com To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Sat Jun 10 18:17:28 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 1q81HL-0005sH-5S for geb-bug-gnu-emacs@m.gmane-mx.org; Sat, 10 Jun 2023 18:17:27 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1q81Gy-0001cg-4K; Sat, 10 Jun 2023 12:17:04 -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 1q81Gw-0001cR-Ll for bug-gnu-emacs@gnu.org; Sat, 10 Jun 2023 12:17:02 -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 1q81Gw-0006qh-Di for bug-gnu-emacs@gnu.org; Sat, 10 Jun 2023 12:17:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1q81Gv-0000Z1-TV for bug-gnu-emacs@gnu.org; Sat, 10 Jun 2023 12:17:01 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Stefan Monnier Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sat, 10 Jun 2023 16:17:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 63988 X-GNU-PR-Package: emacs Original-Received: via spool by 63988-submit@debbugs.gnu.org id=B63988.16864138202157 (code B ref 63988); Sat, 10 Jun 2023 16:17:01 +0000 Original-Received: (at 63988) by debbugs.gnu.org; 10 Jun 2023 16:17:00 +0000 Original-Received: from localhost ([127.0.0.1]:36152 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1q81Gt-0000Yi-Jx for submit@debbugs.gnu.org; Sat, 10 Jun 2023 12:16:59 -0400 Original-Received: from mailscanner.iro.umontreal.ca ([132.204.25.50]:30142) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1q81Gr-0000YR-FZ for 63988@debbugs.gnu.org; Sat, 10 Jun 2023 12:16:58 -0400 Original-Received: from pmg3.iro.umontreal.ca (localhost [127.0.0.1]) by pmg3.iro.umontreal.ca (Proxmox) with ESMTP id 34D83440962; Sat, 10 Jun 2023 12:16:52 -0400 (EDT) Original-Received: from mail01.iro.umontreal.ca (unknown [172.31.2.1]) by pmg3.iro.umontreal.ca (Proxmox) with ESMTP id B4AEB440275; Sat, 10 Jun 2023 12:16:46 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=iro.umontreal.ca; s=mail; t=1686413806; bh=G5zdMvhlHA0dLhQJCX+iIC6SW8QWEBC3k3p4UdryPQE=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=j3DHo0/pCSKlerUtCjDnLbz5d4LchUZPOQqcdRbSPbCny0+A3V9WP6khbJBR+EXTO g72c69SKPazfgKbD+BpnxayzSa0OiNgRw8kXw1qafnnvkSVuPk7Ma3iVl2wSfs6EU6 98RuiFaYrTC3ihGq3QfScrkXKLJvOXE6peYQTr5JdzjaOdUvtpvKFc9+QBr6qcMBEi UPXtAbExiFWARfUddN/efHXy2NUwRRdUP0p+JaGrP/NM/f5C1ws6OyLjS81T95mUeB S/tpHrT04hrskjF7F2rN7EVnBND+06O1cjw3xO5lGbozqtJUNaXHanMz2+5I4J0ReU rkr1c7xF6WqsQ== Original-Received: from pastel (76-10-180-239.dsl.teksavvy.com [76.10.180.239]) by mail01.iro.umontreal.ca (Postfix) with ESMTPSA id 827EE1208E3; Sat, 10 Jun 2023 12:16:46 -0400 (EDT) In-Reply-To: <83wn0bzoeb.fsf@gnu.org> (Eli Zaretskii's message of "Sat, 10 Jun 2023 11:56:28 +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" 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:263225 Archived-At: >> It causes infinite recursion, since format-mode-line also calls >> window_wants_header_line (indirectly). I wonder why `format-mode-line` calls `window_wants_header_line`. Is there a deep technical reason, or just an accident of how we currently implement the feature? > However, I wonder whether we should rethink this minor feature. > Perhaps this minor convenience is not worth the complications? IIUC This is talking about commit 4f66cbbfe520ee31ef26676e09a926217d9736fe which extends the special treatment of a nil `header-line-format` to also hide the header line when its value is "equivalent" to nil. In the past I've wished for a non-nil mode-line that is not displayed because it's equivalent to nil, so I think the feature makes sense, but I agree it's not super important. Maybe if we want to make it work well, the better solution is to memoize the computation of (format-mode-line header-line-format) so that it's called at most once per redisplay? Stefan