From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#72692: Emacs 31.05 (40eecd594ac) get SIGSEGV on Linux (Linux 6.6.45 Kde Wayland) Date: Wed, 28 Aug 2024 15:51:42 +0300 Message-ID: <86seuohktd.fsf@gnu.org> References: <8b1c8e1f-e0b9-4049-888c-3f723e0008a9@gmail.com> <86bk1gxz1z.fsf@mail.linkov.net> <86v7zojuqw.fsf@gnu.org> <87y14j25mg.fsf@protonmail.com> <86cylvjw5l.fsf@gnu.org> <87r0ab14ye.fsf@protonmail.com> <861q2ajilw.fsf@gnu.org> <877cc122ik.fsf@protonmail.com> <865xrkj2mg.fsf@gnu.org> <87mskwzw9k.fsf@protonmail.com> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="39216"; mail-complaints-to="usenet@ciao.gmane.io" Cc: execvy@gmail.com, 72692@debbugs.gnu.org, juri@linkov.net To: Pip Cet Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Wed Aug 28 14:52:32 2024 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1sjIA3-0009uW-OK for geb-bug-gnu-emacs@m.gmane-mx.org; 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Wed, 28 Aug 2024 08:52:53 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sjI9P-000569-0w; Wed, 28 Aug 2024 08:51:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=References:Subject:In-Reply-To:To:From:Date: mime-version; bh=D49N91R0HUzNqbmvoCaSOlCeOZSOOdznV+rJ8Tg9pWw=; b=DxQatM7YMOYV zmeLizJrQ+U4NbxLYlgGQSt8WMAeKXo6a8w7Xt8SYN6h7Ux3Najt1igEstkj67sup5K9rzePTNNn4 BVGAgR5oqHU615SLXDTmPGLq4erbvyBP528pGwe5shf5PjvD9inZHTJLIrIHVW3uKQVZsFex8Bmqa a36ZOqZ0Wp3Y8p5hGZoizXZGiD98IsW98mfIAwsLM914ZxcLkLmU8LHPg7QG7DPtsENyhktIXLtu+ 3JGU4RLNAkKGbKEeLeVRN8RuvNANmccPbIGucAJve2cOxgyjqPQsxzGWDqPl2eJVHPYE22tN63n91 Mxs71Dz/vvj21CGfVzmyJA==; In-Reply-To: <87mskwzw9k.fsf@protonmail.com> (message from Pip Cet on Wed, 28 Aug 2024 12:07:05 +0000) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.bugs:290865 Archived-At: > Date: Wed, 28 Aug 2024 12:07:05 +0000 > From: Pip Cet > Cc: execvy@gmail.com, 72692@debbugs.gnu.org, juri@linkov.net > > >> >> The code path without assertions is similar, it just that the > >> >> XCHAR_TABLE happens further down the call stack, in fontset_find_font. > >> >> See the original backtrace. > >> > > >> > OK, so adding protection against fontset being nil, where we currently > >> > lack that, should take care of these cases, right? > >> > >> It'll turn a segfaulting bug into a wrong-behavior bug. > > > > That depends on what the code we install to handle the nil case will > > do, no? If we do it correctly (assuming there is a correct way of > > handling this), there will be no wrong behavior, right? > > Yes, but that would require much more than checking for nil, it would > mean checking that the fontset entry is still valid and refers to the > same fontset it did originally, not a new fontset. Yes, for the case of a non-nil but different fontset we need a separate fix. But that is a separate problem; I was talking only about the case when the fontset was removed from the cache and its slot set to nil. We already have tests for this in many cases, but not in all of them. I will try to come up with something when I have time.