From mboxrd@z Thu Jan 1 00:00:00 1970 Path: main.gmane.org!not-for-mail From: David Abrahams Newsgroups: gmane.emacs.devel Subject: Re: [BUG] Emacs thinks it has a BDF font Date: Wed, 01 Oct 2003 07:25:32 -0400 Sender: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Message-ID: References: NNTP-Posting-Host: deer.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: sea.gmane.org 1065054568 7783 80.91.224.253 (2 Oct 2003 00:29:28 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Thu, 2 Oct 2003 00:29:28 +0000 (UTC) Cc: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Thu Oct 02 02:29:26 2003 Return-path: Original-Received: from quimby.gnus.org ([80.91.224.244]) by deer.gmane.org with esmtp (Exim 3.35 #1 (Debian)) id 1A4rLS-0005zL-00 for ; Thu, 02 Oct 2003 02:29:26 +0200 Original-Received: from monty-python.gnu.org ([199.232.76.173]) by quimby.gnus.org with esmtp (Exim 3.35 #1 (Debian)) id 1A4rLS-0004JY-00 for ; Thu, 02 Oct 2003 02:29:26 +0200 Original-Received: from localhost ([127.0.0.1] helo=monty-python.gnu.org) by monty-python.gnu.org with esmtp (Exim 4.24) id 1A4rJv-0004PH-8X for emacs-devel@quimby.gnus.org; Wed, 01 Oct 2003 20:27:51 -0400 Original-Received: from list by monty-python.gnu.org with tmda-scanned (Exim 4.24) id 1A4fSc-0006qh-5J for emacs-devel@gnu.org; Wed, 01 Oct 2003 07:48:02 -0400 Original-Received: from mail by monty-python.gnu.org with spam-scanned (Exim 4.24) id 1A4f9I-00059j-Ad for emacs-devel@gnu.org; Wed, 01 Oct 2003 07:28:35 -0400 Original-Received: from [199.232.41.8] (helo=mx20.gnu.org) by monty-python.gnu.org with esmtp (TLSv1:DES-CBC3-SHA:168) (Exim 4.24) id 1A4f80-00051k-BL; Wed, 01 Oct 2003 07:26:44 -0400 Original-Received: from [207.172.4.61] (helo=smtp02.mrf.mail.rcn.net) by mx20.gnu.org with esmtp (Exim 4.24) id 1A4f6w-0001iR-W3; Wed, 01 Oct 2003 07:25:39 -0400 Original-Received: from 209-150-60-107.c3-0.smr-ubr2.sbo-smr.ma.cable.rcn.com ([209.150.60.107] helo=PENGUIN.boost-consulting.com) by smtp02.mrf.mail.rcn.net with esmtp (Exim 3.35 #4) id 1A4f6v-0002w8-00; Wed, 01 Oct 2003 07:25:37 -0400 Original-To: Jason Rumney In-Reply-To: (Jason Rumney's message of "01 Oct 2003 08:40:11 +0100") User-Agent: Gnus/5.1003 (Gnus v5.10.3) Emacs/21.3.50 (windows-nt) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.2 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:16840 X-Report-Spam: http://spam.gmane.org/gmane.emacs.devel:16840 Jason Rumney writes: > David Abrahams writes: > >> In http://article.gmane.org/gmane.emacs.devel/16583/ I reported that >> emacs is following an execution path which attempts to draw a BDF font >> even though none is in use, resulting in a crash deep in the drawing >> machinery about once a day for me. I'm unfamiliar with this part of >> Emacs' display code. Is there someone who can give me a little >> guidance about what to assert, where to set a breakpoint, or something >> (anything) that will help us to track this down? > > In a previous report, you mentioned that this occured when you were > using Gnus 5.10. Does that try to use a BDF font behind your back? I don't think so. I have two emacs' running at all times, only one of which runs GNUs, and the other one is just as likely to crash (perhaps more likely). > If not, then you are probably looking at stack or heap > corruption. Since it is happening in display code variables that are > exected to change frequently, it will be very difficult to track > down with data breakpoints. Or at all. > Take a look at the structures involved, I have, briefly. It's hard to make much of them; they are so complex. Is there a guide to the display structures somewhere? > and see if there are any arrays that might overrun. assert that the > length is within limits wherever they are written. See if you can work > out what variables are next to the font structure on the heap or stack > when the bug occurs. Add assertions to any arrays writes there too. I guess this is going to be a tough one... Thanks for the tips, Dave -- Dave Abrahams Boost Consulting www.boost-consulting.com