From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Lars Ingebrigtsen Newsgroups: gmane.emacs.bugs Subject: bug#57804: An infinite loop in a `fontify-region' function causes Emacs to hang indefinitely Date: Wed, 14 Sep 2022 18:41:53 +0200 Message-ID: <87pmfx6h7y.fsf@gnus.org> References: Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="8058"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/29.0.50 (gnu/linux) Cc: 57804@debbugs.gnu.org To: Paul Pogonyshev Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Wed Sep 14 19:32:36 2022 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 1oYWFX-0001sL-DX for geb-bug-gnu-emacs@m.gmane-mx.org; Wed, 14 Sep 2022 19:32:35 +0200 Original-Received: from localhost ([::1]:44926 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oYWFV-0006Lj-Tl for geb-bug-gnu-emacs@m.gmane-mx.org; Wed, 14 Sep 2022 13:32:33 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:33328) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oYVTb-0004Cd-8e for bug-gnu-emacs@gnu.org; Wed, 14 Sep 2022 12:43:03 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:38970) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1oYVTa-0001V3-JR for bug-gnu-emacs@gnu.org; Wed, 14 Sep 2022 12:43:03 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1oYVTa-0005VP-2g for bug-gnu-emacs@gnu.org; Wed, 14 Sep 2022 12:43:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Lars Ingebrigtsen Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Wed, 14 Sep 2022 16:43:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 57804 X-GNU-PR-Package: emacs Original-Received: via spool by 57804-submit@debbugs.gnu.org id=B57804.166317372621080 (code B ref 57804); Wed, 14 Sep 2022 16:43:02 +0000 Original-Received: (at 57804) by debbugs.gnu.org; 14 Sep 2022 16:42:06 +0000 Original-Received: from localhost ([127.0.0.1]:55901 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1oYVSg-0005Tv-Eo for submit@debbugs.gnu.org; Wed, 14 Sep 2022 12:42:06 -0400 Original-Received: from quimby.gnus.org ([95.216.78.240]:51472) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1oYVSd-0005TM-2g for 57804@debbugs.gnu.org; Wed, 14 Sep 2022 12:42:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnus.org; s=20200322; h=Content-Type:MIME-Version:Message-ID:Date:References: In-Reply-To:Subject:Cc:To:From:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=bTBey3Q+r14Cjdy6gi8c60skPhvcImnNTBVDb7KeEGk=; b=Yir+u2cWNJvFUlk6xXLpQyFm3N GjkTOG3IgXJ+HsNeHsKkFzlf0ch/EanqC143LHXffu1H9q2vAFCazJXi0lHm1Fo6gf/4YSKlMGdvQ vWCBfOie6fL89DAtxmimnCsJxZP+HlVy+f/SzuCg4X/W2kAdsStrvFP4pzGZu2TePtQc=; Original-Received: from [84.212.220.105] (helo=joga) by quimby.gnus.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1oYVST-0008Qd-Nw; Wed, 14 Sep 2022 18:41:56 +0200 In-Reply-To: (Paul Pogonyshev's message of "Wed, 14 Sep 2022 17:05:54 +0200") X-Now-Playing: Insides's _Soft Bonds_: "Ghost Music" 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" Xref: news.gmane.io gmane.emacs.bugs:242491 Archived-At: Paul Pogonyshev writes: > C-g doesn't help anymore. The only thing you can do is to kill and start Emacs anew. [...] > (define-derived-mode buggy-mode nil "buggy" > (setf font-lock-defaults '(nil nil t nil (font-lock-fontify-region-function . buggy-fontifier))) > (font-lock-mode 1)) > > (defun buggy-fontifier (start end loudly) > (add-face-text-property start (min (+ start 15) end) 'bold) > (while t > "whoopsie") > nil) Yes, it's really unfortunate that you can't get out of errors like this without killing Emacs. We've previously discussed making a certain key sequence disable font locking in a buffer -- or blacklist the particular functions that's inflooping somehow. For instance, if the user hits `C-g' three times (and Emacs doesn't idle in between), then we disable font-lock in that buffer. There's also `max-redisplay-ticks' -- but I'm not sure that would have helped here?