From mboxrd@z Thu Jan  1 00:00:00 1970
Path: news.gmane.org!not-for-mail
From: Eli Zaretskii <eliz@gnu.org>
Newsgroups: gmane.emacs.devel
Subject: Re: transpose-regions
Date: Fri, 23 Mar 2007 15:46:04 +0200
Message-ID: <ups703wf7.fsf@gnu.org>
References: <46026277.7060305@gmx.at> <87odml9v67.fsf@stupidchicken.com>
	<4602A015.2080403@gmx.at> <87bqil5kxd.fsf@stupidchicken.com>
	<4602B7B5.1070705@gmx.at> <87y7lp886g.fsf@stupidchicken.com>
Reply-To: Eli Zaretskii <eliz@gnu.org>
NNTP-Posting-Host: lo.gmane.org
X-Trace: sea.gmane.org 1174657578 15440 80.91.229.12 (23 Mar 2007 13:46:18 GMT)
X-Complaints-To: usenet@sea.gmane.org
NNTP-Posting-Date: Fri, 23 Mar 2007 13:46:18 +0000 (UTC)
Cc: rudalics@gmx.at, emacs-devel@gnu.org
To: Chong Yidong <cyd@stupidchicken.com>
Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Fri Mar 23 14:46:11 2007
Return-path: <emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org>
Envelope-to: ged-emacs-devel@m.gmane.org
Original-Received: from lists.gnu.org ([199.232.76.165])
	by lo.gmane.org with esmtp (Exim 4.50)
	id 1HUk5r-00027W-Au
	for ged-emacs-devel@m.gmane.org; Fri, 23 Mar 2007 14:46:11 +0100
Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43)
	id 1HUk7l-0004OX-6M
	for ged-emacs-devel@m.gmane.org; Fri, 23 Mar 2007 08:48:09 -0500
Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1HUk7h-0004Jj-Mv
	for emacs-devel@gnu.org; Fri, 23 Mar 2007 09:48:05 -0400
Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1HUk7g-0004Gl-5o
	for emacs-devel@gnu.org; Fri, 23 Mar 2007 09:48:05 -0400
Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1HUk7g-0004GJ-23
	for emacs-devel@gnu.org; Fri, 23 Mar 2007 08:48:04 -0500
Original-Received: from nitzan.inter.net.il ([213.8.233.22])
	by monty-python.gnu.org with esmtp (Exim 4.60)
	(envelope-from <eliz@gnu.org>) id 1HUk5k-0008ES-Um
	for emacs-devel@gnu.org; Fri, 23 Mar 2007 09:46:05 -0400
Original-Received: from HOME-C4E4A596F7 ([81.5.34.178])
	by nitzan.inter.net.il (MOS 3.7.3a-GA)
	with ESMTP id GJA71059 (AUTH halo1);
	Fri, 23 Mar 2007 15:46:02 +0200 (IST)
In-reply-to: <87y7lp886g.fsf@stupidchicken.com> (message from Chong Yidong on
	Thu, 22 Mar 2007 14:06:15 -0400)
X-detected-kernel: FreeBSD 4.7-5.2 (or MacOS X 10.2-10.4) (2)
X-BeenThere: emacs-devel@gnu.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: "Emacs development discussions." <emacs-devel.gnu.org>
List-Unsubscribe: <http://lists.gnu.org/mailman/listinfo/emacs-devel>,
	<mailto:emacs-devel-request@gnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/pipermail/emacs-devel>
List-Post: <mailto:emacs-devel@gnu.org>
List-Help: <mailto:emacs-devel-request@gnu.org?subject=help>
List-Subscribe: <http://lists.gnu.org/mailman/listinfo/emacs-devel>,
	<mailto:emacs-devel-request@gnu.org?subject=subscribe>
Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org
Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org
Xref: news.gmane.org gmane.emacs.devel:68390
Archived-At: <http://permalink.gmane.org/gmane.emacs.devel/68390>

> From: Chong Yidong <cyd@stupidchicken.com>
> Date: Thu, 22 Mar 2007 14:06:15 -0400
> Cc: emacs-devel <emacs-devel@gnu.org>
> 
> > #4  0x0107e521 in Flength (sequence=35193781) at fns.c:185
> > (gdb) p sequence
> > $1 = 35193768
> > (gdb) xtype
> > Lisp_Int
> > (gdb) xsymbol
> > $2 = (struct Lisp_Symbol *) 0x21903a8
> > 0
> 
> Could you double check this?
> 
> Flength was called with sequence=35193781; how did it mutate into
> 35193768?  The code in Flength doesn't change the value of sequence
> (unless it is a cons cell, in which case it wouldn't end up in the
> "else" code path.)  The only way this could happen is if something
> clobbers the stack.... maybe a compiler bug?

More likely a result of optimized code confusing GDB.