From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Chris Hall Newsgroups: gmane.emacs.bugs Subject: Re: 23.0.60; Seg fault in xfaces.c at line 6703 (Emacs.app on GNUstep) Date: Sun, 03 Feb 2008 17:20:25 -1000 Message-ID: <5c3f50e8df2b05f7f2e7b1843d425e14@lagorda> References: <47A6299E.70208@gnu.org> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 (Generated by Pantomime 1.2.0) Content-Type: text/plain; charset="us-ascii"; format="flowed" X-Trace: ger.gmane.org 1202095804 5467 80.91.229.12 (4 Feb 2008 03:30:04 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Mon, 4 Feb 2008 03:30:04 +0000 (UTC) Cc: Emacs bugs , Dan Nicolaescu To: Jason Rumney Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Mon Feb 04 04:30:25 2008 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1JLs2K-0003qP-V3 for geb-bug-gnu-emacs@m.gmane.org; Mon, 04 Feb 2008 04:30:25 +0100 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1JLs1t-0000Lg-0u for geb-bug-gnu-emacs@m.gmane.org; Sun, 03 Feb 2008 22:29:57 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1JLrp3-0007OW-Rg for bug-gnu-emacs@gnu.org; Sun, 03 Feb 2008 22:16:41 -0500 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1JLroz-0007KJ-R9 for bug-gnu-emacs@gnu.org; Sun, 03 Feb 2008 22:16:40 -0500 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1JLroz-0007KD-OQ for bug-gnu-emacs@gnu.org; Sun, 03 Feb 2008 22:16:37 -0500 Original-Received: from out2.smtp.messagingengine.com ([66.111.4.26]) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1JLrou-0006ta-9E; Sun, 03 Feb 2008 22:16:32 -0500 Original-Received: from compute1.internal (compute1.internal [10.202.2.41]) by out1.messagingengine.com (Postfix) with ESMTP id 873488F888; Sun, 3 Feb 2008 22:16:29 -0500 (EST) Original-Received: from heartbeat2.messagingengine.com ([10.202.2.161]) by compute1.internal (MEProxy); Sun, 03 Feb 2008 22:16:29 -0500 X-Sasl-enc: UaQ9ypAEITl0TTFnCAolVpADjx4G6aHe/4vnLm+2rgcc 1202094989 Original-Received: from localhost.localdomain (75-95-220-61.hon.clearwire-dns.net [75.95.220.61]) by mail.messagingengine.com (Postfix) with ESMTP id 26731278B5; Sun, 3 Feb 2008 22:16:29 -0500 (EST) Original-Received: from localhost ([127.0.0.1] helo=localhost.localdomain ident=cjh) by localhost.localdomain with esmtp (Exim 4.50) id 1JLrsf-0001ul-Bt; Sun, 03 Feb 2008 17:20:25 -1000 In-Reply-To: <47A6299E.70208@gnu.org> User-Agent: GNUMail (Version 1.2.0) X-detected-kernel: by monty-python.gnu.org: Genre and OS details not recognized. X-Mailman-Approved-At: Sun, 03 Feb 2008 22:29:44 -0500 X-BeenThere: bug-gnu-emacs@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:17464 Archived-At: On 2008-02-03 10:52:46 -1000 Jason Rumney wrote: > Chris Hall wrote: >> I think there are 2 issues here: the presence of the value '0x0' in >> a field >> meant to contain a pointer to a face_cache struct, and what the >> presence of >> that value causes to happen. >> >> To me it seems that while almost certainly the former is an >> Emacs.app >> issue, the latter is more likely an Emacs 23.0.60 issue. I don't >> know for >> sure, since I'm not an Emacs or Emacs.app hacker. >> >> I am aware that sometimes some classes of errors are perhaps best >> allowed >> to happen and to result in catastrophic failures like segmentation >> faults, >> but in this case, were this one of my programs I'd probably consider >> it a >> bug. > > If it is a bug to have 0 in that field, why would you hide the bug by > avoiding a crash when it is 0? > So it could terminate gracefully while reporting that it had a 0 in that field, along with any other available information that might prove useful in helping to solve the problem? Maybe offer to run in text mode with that information made available in a buffer with a bug report? I didn't mention anything about 'hiding' it, did I? With the patch I supplied, at least the user knows there is an issue with realizing the default face, rather than SIGSEGV (11). But of course, and as always, YMMV. Obviously, the possibility of the default face not being realized was anticipated by somebody, and considered serious enough to terminate execution -- there was already in place a check for exactly that, and the possibility of issuing a message and then deliberately 'erroring out' of the program if it hadn't been realized. >> but in this case, For whatever reason, there is instead no properly initialized 'face_cache' struct available, if I am interpreting the '0x0' correctly. AFAIK, the '0x0' is the result of an *un*anticipated case leading to the same check. I don't know, and probably never will, because as I mentioned, I am unaware of the larger program execution context, and I am time-constrained with respect to learning sufficiently the Emacs internals required to make that determination. Cheers! Chris Hall