From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Alan Mackenzie Newsgroups: gmane.emacs.devel Subject: Re: Questionable code in handling of wordend in the regexp engine in regex-emacs.c Date: Sat, 2 Mar 2019 13:18:01 +0000 Message-ID: <20190302131801.GB21061@ACM> References: <83bm2uiu6x.fsf@gnu.org> <20190301141448.GC5674@ACM> <834l8mirj9.fsf@gnu.org> <20190301145856.GE5674@ACM> <83zhqeh8ds.fsf@gnu.org> <20190301163824.GF5674@ACM> <20190301191607.GG5674@ACM> <83woligzmu.fsf@gnu.org> <20190302111640.GA21061@ACM> <83fts5h3lz.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="202522"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: Mutt/1.10.1 (2018-07-13) Cc: monnier@iro.umontreal.ca, emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Mar 02 14:23:32 2019 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1h04bz-000qYJ-1g for ged-emacs-devel@m.gmane.org; Sat, 02 Mar 2019 14:23:31 +0100 Original-Received: from localhost ([127.0.0.1]:54550 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h04bx-0002zn-RO for ged-emacs-devel@m.gmane.org; Sat, 02 Mar 2019 08:23:29 -0500 Original-Received: from eggs.gnu.org ([209.51.188.92]:41287) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h04bj-0002yL-AX for emacs-devel@gnu.org; Sat, 02 Mar 2019 08:23:16 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1h04bi-0001DI-7H for emacs-devel@gnu.org; Sat, 02 Mar 2019 08:23:15 -0500 Original-Received: from colin.muc.de ([193.149.48.1]:64379 helo=mail.muc.de) by eggs.gnu.org with smtp (Exim 4.71) (envelope-from ) id 1h04bh-0001Aw-UK for emacs-devel@gnu.org; Sat, 02 Mar 2019 08:23:14 -0500 Original-Received: (qmail 86603 invoked by uid 3782); 2 Mar 2019 13:23:12 -0000 Original-Received: from acm.muc.de (p4FE150E7.dip0.t-ipconnect.de [79.225.80.231]) by colin.muc.de (tmda-ofmipd) with ESMTP; Sat, 02 Mar 2019 14:23:11 +0100 Original-Received: (qmail 32506 invoked by uid 1000); 2 Mar 2019 13:18:01 -0000 Content-Disposition: inline In-Reply-To: <83fts5h3lz.fsf@gnu.org> X-Delivery-Agent: TMDA/1.1.12 (Macallan) X-Primary-Address: acm@muc.de X-detected-operating-system: by eggs.gnu.org: FreeBSD 9.x [fuzzy] X-Received-From: 193.149.48.1 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 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" Xref: news.gmane.org gmane.emacs.devel:233765 Archived-At: Hello, Eli. On Sat, Mar 02, 2019 at 14:18:00 +0200, Eli Zaretskii wrote: > > Date: Sat, 2 Mar 2019 11:16:40 +0000 > > Cc: monnier@iro.umontreal.ca, emacs-devel@gnu.org > > From: Alan Mackenzie > > On the coding tests, we fail in one of them when bytepos == 1, and the > > first byte in the buffer is 0xa4. The Lisp call stack at the time is > > Lisp Backtrace: > > "decode-coding-region" (0xc35b5cb0) > Ah, yes. We should do this to prevent such false alarms: > eassert (NILP (BVAR (b, enable_multibyte_characters)) > || bytepos >= BUF_Z_BYTE (b) > || CHAR_HEAD_P (BUF_FETCH_BYTE (b, bytepos))); > IOW, this test is irrelevant in unibyte buffers. Instead I moved the eassert to after the bit where it checks for unibyte buffers, giving this: diff --git a/src/marker.c b/src/marker.c index b58051a8c2..0b2e1bf5c6 100644 --- a/src/marker.c +++ b/src/marker.c @@ -332,6 +332,10 @@ buf_bytepos_to_charpos (struct buffer *b, ptrdiff_t bytepos) if (best_above == best_above_byte) return bytepos; + /* Check bytepos is not in the middle of a character. */ + eassert (bytepos >= BUF_Z_BYTE (b) + || CHAR_HEAD_P (BUF_FETCH_BYTE (b, bytepos))); + best_below = BEG; best_below_byte = BEG_BYTE; I now no longer see the failed easserts in make check. So I'll commit this sometime (real life is a bit urgent right now). > Thanks. -- Alan Mackenzie (Nuremberg, Germany).