From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Thomas Fitzsimmons Newsgroups: gmane.emacs.bugs Subject: bug#63711: 30.0.50; Crash in xdisp.c when it->string is 0x0 Date: Thu, 25 May 2023 09:50:44 -0400 Message-ID: References: <83ilcgn9ud.fsf@gnu.org> <835y8gmt3f.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="4814"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Cc: 63711@debbugs.gnu.org To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Thu May 25 15:51:18 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 1q2BN5-0000vI-7t for geb-bug-gnu-emacs@m.gmane-mx.org; Thu, 25 May 2023 15:51:16 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1q2BMw-0004Jq-Ra; Thu, 25 May 2023 09:51:06 -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 1q2BMs-0004JY-Jd for bug-gnu-emacs@gnu.org; Thu, 25 May 2023 09:51:02 -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 1q2BMs-0002C9-BR for bug-gnu-emacs@gnu.org; Thu, 25 May 2023 09:51:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1q2BMs-0000zs-5c for bug-gnu-emacs@gnu.org; Thu, 25 May 2023 09:51:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Thomas Fitzsimmons Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Thu, 25 May 2023 13:51:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 63711 X-GNU-PR-Package: emacs Original-Received: via spool by 63711-submit@debbugs.gnu.org id=B63711.16850226533817 (code B ref 63711); Thu, 25 May 2023 13:51:02 +0000 Original-Received: (at 63711) by debbugs.gnu.org; 25 May 2023 13:50:53 +0000 Original-Received: from localhost ([127.0.0.1]:46308 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1q2BMi-0000zU-SU for submit@debbugs.gnu.org; Thu, 25 May 2023 09:50:53 -0400 Original-Received: from mail.fitzsim.org ([69.165.165.189]:50386) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1q2BMh-0000zI-1w for 63711@debbugs.gnu.org; Thu, 25 May 2023 09:50:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=fitzsim.org ; s=20220430; h=Content-Type:MIME-Version:Message-ID:Date:References: In-Reply-To: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=Rrpz1AjWirCx+xVzisMI+m4ZS56jaQDWzsRHmyAARRg=; b=E3Oiv9923EJGZ9fVyq8Dm1DlRL EfmRs3ul8VutPSIx3tMi+HfprfQtTazo7vIHLxxSnMedEahiUhJG5+79b6857NcpY9+J+IeZJYWS9 doQDSjCJQir8xjOazYCLFCLli5AA/MuOS1b8A14pbubw3zRIKEFF/31dPxMyoJgX9uTBFkkAY1fRe x0maoML585OGTWVLYcbGpo95J4EDSUcgymen1ohemAJjfzP7p+0upffmFxZJ6Nc2/ei8EForI2Phh sNvE2SHvyMdcXNgTBNBpV9TwHxvZTLuUWIqnHfq7cYpyHMDvEBWsDSpy8NBY7is9FANaaas/wt3i3 J0Du6yLA==; Original-Received: from [192.168.1.1] (helo=localhost.localdomain) by mail.fitzsim.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94.2) (envelope-from ) id 1q2BMb-000MwC-CI; Thu, 25 May 2023 09:50:45 -0400 In-Reply-To: <835y8gmt3f.fsf@gnu.org> (Eli Zaretskii's message of "Thu, 25 May 2023 16:35:48 +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:262371 Archived-At: Eli Zaretskii writes: >> From: Thomas Fitzsimmons >> Cc: 63711@debbugs.gnu.org >> Date: Thu, 25 May 2023 09:02:26 -0400 >> >> > (gdb) p it->sp >> >> $11 = 0 >> >> > (gdb) p it->method >> >> $12 = GET_FROM_BUFFER > > These last two values are already a sign of trouble, AFAIU. We are > trying to find an overlay string where there is none. But if that is > the case, how come pos->overlay_string_index is non-negative? that > should not happen. OK, interesting. >> The session is still open if you want me to check other values. > > Do you know what kind of buffer is the current buffer in this case? > The following command will show some of the buffer text near the > position that is examined here, to possibly help you figure out the > buffer: > > (gdb) p (*BYTE_POS_ADDR(pos->pos.bytepos))@100 > > (Here 100 is the number of bytes to display; feel free to use more if > 100 is insufficient.) $14 = "\000\000;; js.el --- Major mode for editing JavaScript -*- lexical-binding: t -*-\n\n;; Copyright (C) 2008-" > Once you do understand what buffer is this, please try to describe the > overlays at buffer position pos->pos.charpos in that buffer, if there > are supposed to be any overlays there. (gdb) p pos->pos.charpos $16 = 0 So I guess the first 100 characters printed above already shows the context at pos->pos.charpos? Are those leading zero-bytes expected? > That position is supposed to be the first position of a screen line, > i.e. the position of the leftmost character on display in that line. I was experimenting with font-locking JavaScript. Maybe I put Emacs into a strange state that way (though it still shouldn't be crashable). I can't visually inspect the affected window anymore; it was an X11 window, tunneled through an SSH connection which I've since closed. Thanks, Thomas