From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Ryan Johnson Newsgroups: gmane.emacs.devel Subject: Re: 64-bit emacs crashes a lot Date: Fri, 16 Aug 2013 07:37:53 -0400 Message-ID: <520E0F11.6050306@cs.utoronto.ca> References: <51F3151D.7040000@cs.utoronto.ca> <51F33565.1090406@cornell.edu> <51F33F52.4060405@cs.utoronto.ca> <51FB1D9E.5090102@cs.utoronto.ca> <20130802080211.GA18054@calimero.vinschen.de> <51FB9228.2020309@cornell.edu> <51FBA100.90005@cs.utoronto.ca> <51FD5462.5020400@cs.utoronto.ca> <51FFBDFF.7040501@cornell.edu> <51FFC4F2.8080909@cs.utoronto.ca> <5203D89E.6030801@cornell.edu> <5203DCCA.1010105@cs.utoronto.ca> <5205B364.8090007@cs.utoronto.ca> <52064730.50404@cornell.edu> <"52065B3C.6060104@cs.utoronto <520CCA41.3000107"@cs.utoronto.ca> <520D089A.1020806@cornell.edu> <83ioz6op5v.fsf@gnu.org> <520D4036.8010303@cs.utoronto.ca> <8361v6nhdb.fsf@gnu.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1376658616 28056 80.91.229.3 (16 Aug 2013 13:10:16 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 16 Aug 2013 13:10:16 +0000 (UTC) Cc: emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Fri Aug 16 15:10:18 2013 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1VAJnF-000639-7I for ged-emacs-devel@m.gmane.org; Fri, 16 Aug 2013 15:10:17 +0200 Original-Received: from localhost ([::1]:58866 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VAJnE-0003yD-7I for ged-emacs-devel@m.gmane.org; Fri, 16 Aug 2013 09:10:16 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:35154) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VAIMG-0007Xd-KK for emacs-devel@gnu.org; Fri, 16 Aug 2013 07:38:25 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VAIMB-0002da-QW for emacs-devel@gnu.org; Fri, 16 Aug 2013 07:38:20 -0400 Original-Received: from bureau92.ns.utoronto.ca ([128.100.132.250]:43941) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VAIMB-0002WH-M4; Fri, 16 Aug 2013 07:38:15 -0400 Original-Received: from [192.168.0.106] (76-10-140-156.dsl.teksavvy.com [76.10.140.156]) (authenticated bits=0) by bureau92.ns.utoronto.ca (8.13.8/8.13.8) with ESMTP id r7GBbx5Q032404 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Fri, 16 Aug 2013 07:38:01 -0400 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130801 Thunderbird/17.0.8 In-Reply-To: <8361v6nhdb.fsf@gnu.org> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 128.100.132.250 X-Mailman-Approved-At: Fri, 16 Aug 2013 09:10:12 -0400 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 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.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:162807 Archived-At: On 16/08/2013 4:56 AM, Eli Zaretskii wrote: > I'm not subscribed to this list, so if you want me to reply, please CC > me explicitly. Besides, this discussion should be moved to > emacs-devel@gnu.org, since I don't see anything Cygwin specific here > at this point. > >> Date: Thu, 15 Aug 2013 16:55:18 -0400 >> From: Ryan Johnson >> >> On 15/08/2013 1:10 PM, Eli Zaretskii wrote: >>>> Date: Thu, 15 Aug 2013 12:58:02 -0400 >>>> From: Ken Brown >>>> CC: Eli Zaretskii >>>> >>>> Eli is the expert on bidi.c (he wrote it). He can probably tell you >>>> whether you've really bumped into an emacs bug here. >>> There's nothing wrong with bidi.c here, it just aborts because it is >>> handed an invalid character codepoint. It would have been useful to >>> see the value of that character. >> I guess I would just consider crashing to be overkill for a bad byte on >> the input stream... > It's not a crash, it's a deliberate abort. Any invalid codepoint at > such low level of the Emacs display engine means only one thing: a > bug, and a grave one at that. Such bugs must be flagged prominently > and unequivocally, prompting users to report them. We could in > principle "recover" by substituting some other character, but such > recovery would only sweep a grave problem under the carpet. Since > Emacs isn't a safety-critical program, and auto-saves your edits > before it commits suicide, such recovery feature is deemed > inappropriate, and detrimental to the general quality of Emacs code in > the long run. OK, makes sense. >> and in any case, if 5-byte UTF-8 is illegal, and >> worth dying for, wouldn't it make sense to die right away rather than >> processing it so something else can croak down the road? > See above: yes, it's worth dying for, because I'm quite sure this is a > sign of a very serious trouble in the session anyway. Why does it > matter for you, as a user, whether we abort here or "down the road"? > The principle is to die as soon as possible, because in many cases > this allows to identify the culprit faster and easier. IOW, dying > sooner and faster helps the Emacs maintainers to find and fix problems > without any real effect on the users. Re die as soon as possible: We're in violent agreement: I argued that---if 5-byte UTF-8 is illegal---emacs should abort at the decoding stage (= earlier) rather than at some later point when it discovers the too-large value. In any case, though, I can't repro on a debug build so this whole thing may be moot. Ryan