From mboxrd@z Thu Jan 1 00:00:00 1970 Path: main.gmane.org!not-for-mail From: Richard Stallman Newsgroups: gmane.emacs.devel Subject: Re: repost: segfault on GNU/Linux Date: Sat, 13 Mar 2004 21:56:04 -0500 Sender: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Message-ID: References: <1078443334.6791.2.camel@coltrane.laudi.ka> <1078909835.7805.13.camel@coltrane.laudi.ka> Reply-To: rms@gnu.org NNTP-Posting-Host: deer.gmane.org X-Trace: sea.gmane.org 1079241712 15674 80.91.224.253 (14 Mar 2004 05:21:52 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Sun, 14 Mar 2004 05:21:52 +0000 (UTC) Cc: klaus.berndl@sdm.de, emacs-devel@gnu.org, storm@cua.dk Original-X-From: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Sun Mar 14 06:21:39 2004 Return-path: Original-Received: from quimby.gnus.org ([80.91.224.244]) by deer.gmane.org with esmtp (Exim 3.35 #1 (Debian)) id 1B2O4B-0003xK-00 for ; Sun, 14 Mar 2004 06:21:39 +0100 Original-Received: from monty-python.gnu.org ([199.232.76.173]) by quimby.gnus.org with esmtp (Exim 3.35 #1 (Debian)) id 1B2O4B-0004sE-00 for ; Sun, 14 Mar 2004 06:21:39 +0100 Original-Received: from localhost ([127.0.0.1] helo=monty-python.gnu.org) by monty-python.gnu.org with esmtp (Exim 4.30) id 1B2Nt6-0002uy-Ni for emacs-devel@quimby.gnus.org; Sun, 14 Mar 2004 00:10:12 -0500 Original-Received: from list by monty-python.gnu.org with tmda-scanned (Exim 4.30) id 1B2Ml0-0003gY-4U for emacs-devel@gnu.org; Sat, 13 Mar 2004 22:57:46 -0500 Original-Received: from mail by monty-python.gnu.org with spam-scanned (Exim 4.30) id 1B2MkQ-0003Pn-5k for emacs-devel@gnu.org; Sat, 13 Mar 2004 22:57:42 -0500 Original-Received: from [199.232.76.164] (helo=fencepost.gnu.org) by monty-python.gnu.org with esmtp (Exim 4.30) id 1B2LqU-00006G-Vx for emacs-devel@gnu.org; Sat, 13 Mar 2004 21:59:22 -0500 Original-Received: from rms by fencepost.gnu.org with local (Exim 4.24) id 1B2LnI-0001A3-4F; Sat, 13 Mar 2004 21:56:04 -0500 Original-To: jtl@schlund.de In-reply-to: <1078909835.7805.13.camel@coltrane.laudi.ka> (message from Jens Lautenbacher on Wed, 10 Mar 2004 10:10:35 +0100) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.4 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Xref: main.gmane.org gmane.emacs.devel:20437 X-Report-Spam: http://spam.gmane.org/gmane.emacs.devel:20437 Program received signal SIGSEGV, Segmentation fault. 0x08203e7c in find_interval (tree=3D0x9fc13cc, position=3D1) at intervals.c= :652 652 tree =3D balance_possible_root_interval (tree); (gdb) l That pretty clearly suggests that the interval structure (text properties) contains invalid data. That is very strange, since the previous but seems to concern overlays. Overlays and text properties are different data and are handled by different code. Can you come up with a single reproducible case that always fails in the same way? Fails only with CVS Emacs, Emacs 21.3 works. This means we can't expect the bug to disappear automatically with the next release. XEmacs can't be tested, Even if it could be tested, the results would not teach us anything about this bug. XEmacs does not have either intervals or overlays. All my experience suggests that the approach of trying various cases to look for a pattern of where failures occur is not useful, because it generally does not lead anywhere. The only way to find such bugs is by studying the code in detail, finding what's invalid in the data, and tracing the causality back step by step.