From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Toby Allsopp Newsgroups: gmane.emacs.devel,gmane.emacs.pretest.bugs Subject: Re: 23.0.50; Crash in ediff-regions-linewise Date: Sun, 14 Oct 2007 21:19:57 +1300 Message-ID: <87wstq5cr6.fsf@candyboy.here> References: NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1192374757 31852 80.91.229.12 (14 Oct 2007 15:12:37 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sun, 14 Oct 2007 15:12:37 +0000 (UTC) Cc: emacs-pretest-bug@gnu.org To: rms@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sun Oct 14 17:12:28 2007 Return-path: 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 1Ih58F-0007Ms-9d for ged-emacs-devel@m.gmane.org; Sun, 14 Oct 2007 17:11:55 +0200 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Ih588-0004LK-DA for ged-emacs-devel@m.gmane.org; Sun, 14 Oct 2007 11:11:48 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1IgyjZ-0005tV-8c for emacs-devel@gnu.org; Sun, 14 Oct 2007 04:22:01 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1IgyjY-0005t6-4o for emacs-devel@gnu.org; Sun, 14 Oct 2007 04:22:00 -0400 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1IgyjX-0005t0-Sv for emacs-devel@gnu.org; Sun, 14 Oct 2007 04:22:00 -0400 Original-Received: from fencepost.gnu.org ([140.186.70.10]) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1IgyjX-0007ij-Ke for emacs-devel@gnu.org; Sun, 14 Oct 2007 04:21:59 -0400 Original-Received: from monty-python.gnu.org ([199.232.76.173]) by fencepost.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1IgyjX-0006sD-Cq for emacs-pretest-bug@gnu.org; Sun, 14 Oct 2007 04:21:59 -0400 Original-Received: from Debian-exim by monty-python.gnu.org with spam-scanned (Exim 4.60) (envelope-from ) id 1IgyjT-0007gb-Ql for emacs-pretest-bug@gnu.org; Sun, 14 Oct 2007 04:21:58 -0400 Original-Received: from loadbalancer1.orcon.net.nz ([219.88.242.3] helo=mx5.orcon.net.nz) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1IgyjT-0007ex-3F for emacs-pretest-bug@gnu.org; Sun, 14 Oct 2007 04:21:55 -0400 Original-Received: from Debian-exim by mx5.orcon.net.nz with local (Exim 4.67) (envelope-from ) id 1Igyif-0005xB-BR for emacs-pretest-bug@gnu.org; Sun, 14 Oct 2007 21:21:05 +1300 Original-Received: from 60-234-130-144.bitstream.orcon.net.nz ([60.234.130.144] helo=cecil.here) by mx5.orcon.net.nz with smtp (Exim 4.67) (envelope-from ) id 1IgyiT-0005gB-K4 for emacs-pretest-bug@gnu.org; Sun, 14 Oct 2007 21:20:54 +1300 Original-Received: (qmail 27482 invoked from network); 14 Oct 2007 21:19:57 +1300 Original-Received: from unknown (HELO candyboy.here) (192.168.3.170) by cecil.here with SMTP; 14 Oct 2007 21:19:57 +1300 Original-Received: from toby by candyboy.here with local (Exim 4.67) (envelope-from ) id 1IgyhZ-00055B-TS; Sun, 14 Oct 2007 21:19:57 +1300 In-Reply-To: (Richard Stallman's message of "Sat\, 13 Oct 2007 15\:47\:55 -0400") User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/23.0.50 (gnu/linux) X-DSPAM-Check: by mx5.orcon.net.nz on Sun, 14 Oct 2007 21:21:05 +1300 X-DSPAM-Processed: Sun Oct 14 21:21:05 2007 X-DSPAM-Improbability: 1 in 187 chance of being spam X-detected-kernel: by monty-python.gnu.org: Linux 2.6 (newer, 3) X-detected-kernel: by monty-python.gnu.org: Linux 2.6, seldom 2.4 (older, 4) X-Mailman-Approved-At: Sun, 14 Oct 2007 11:11:45 -0400 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-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:80844 gmane.emacs.pretest.bugs:20128 Archived-At: [I apologise if this is a duplicate message; my ISP bounced my first attempt.] Richard Stallman writes: > The crash occurred trying to print some Lisp data. Probably some data > is invalid -- but which data? Please look at the data to see what if > anything is invalid. It appears that Fmake_indirect_buffer creates a buffer object that is invalid in some way. This then fails a bufferp check and results in an error containing the invalid buffer object. > It appears that the invalid data came from an error. Please try using > a breakpoint in Fsignal to catch it when it generates the error. Then > you can find out where the invalid data came from. Thank you for this suggestion. Stopping at Fsignal was very educational. > We need to see where it was created so we can fix the bug there. The first sign of invalid data that I can find shows up at buffer.c:603: XSETBUFFER (buf, b); After executing this line trying to pp buf results in a segmentation fault: (gdb) pp buf [ Program received signal SIGSEGV, Segmentation fault. 0x00000000005ca9a9 in print_object (obj=-31378459841363086, printcharfun=11387361, escapeflag=1) at /usr/local/src/emacs-cvs/emacs/src/print.c:2072 At this point xbacktrace shows: "make-indirect-buffer" (0x364de598) "ediff-make-indirect-buffer" (0x364deaa8) "ediff-make-cloned-buffer" (0x364defc8) "ediff-clone-buffer-for-region-comparison" (0x364df4e8) "ediff-regions-linewise" (0x364dfa38) "call-interactively" (0x364dfe88) "execute-extended-command" (0x364e01b8) "call-interactively" (0x364e0518) The arguments to make-indirect-buffer look fine: Breakpoint 6, Fmake_indirect_buffer (base_buffer=11255747, name=16778051, clone=16709345) at /usr/local/src/emacs-cvs/emacs/src/buffer.c:554 (gdb) pp base_buffer "*scratch*" (gdb) pp name "*scratch*-Region.A-" (gdb) pp clone clone A slightly easier way to reproduce the crash is: emacs -Q C-x 4 c I hope this helps. Regards, Toby.