From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: martin rudalics Newsgroups: gmane.emacs.devel Subject: Re: [Emacs-diffs] emacs-26 9bf66c6: Don't run FOR_EACH_FRAME when there's no frame left (Bug#29961) Date: Sun, 17 Dec 2017 11:46:33 +0100 Message-ID: <5A364B09.4020905@gmx.at> References: <20171215073120.7671.79446@vcs0.savannah.gnu.org> <20171215073122.52703204D3@vcs0.savannah.gnu.org> <5A34119D.6000407@gmx.at> <5A34EA93.1050501@gmx.at> <9d0b9c22-d386-cd0a-3947-a44d58b1ee0e@cs.ucla.edu> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Trace: blaine.gmane.org 1513507548 20457 195.159.176.226 (17 Dec 2017 10:45:48 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sun, 17 Dec 2017 10:45:48 +0000 (UTC) To: Paul Eggert , Stefan Monnier , emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sun Dec 17 11:45:44 2017 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1eQWS0-00052W-BM for ged-emacs-devel@m.gmane.org; Sun, 17 Dec 2017 11:45:44 +0100 Original-Received: from localhost ([::1]:53805 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eQWTy-0005UT-N7 for ged-emacs-devel@m.gmane.org; Sun, 17 Dec 2017 05:47:46 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:37270) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eQWTK-0005UF-F0 for emacs-devel@gnu.org; Sun, 17 Dec 2017 05:47:07 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eQWTF-0003OR-Jj for emacs-devel@gnu.org; Sun, 17 Dec 2017 05:47:06 -0500 Original-Received: from mout.gmx.net ([212.227.15.15]:51592) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1eQWTF-0003N6-A7 for emacs-devel@gnu.org; Sun, 17 Dec 2017 05:47:01 -0500 Original-Received: from [192.168.1.100] ([46.125.250.16]) by mail.gmx.com (mrgmx001 [212.227.17.190]) with ESMTPSA (Nemesis) id 0M6ilI-1fBuWF2cLs-00wWP7; Sun, 17 Dec 2017 11:46:43 +0100 In-Reply-To: <9d0b9c22-d386-cd0a-3947-a44d58b1ee0e@cs.ucla.edu> X-Provags-ID: V03:K0:6Y4AZnmcpsPAzz6+DbGbr9RhLDzXwcv9hZ+YjNROwdKYFgrxD3W grWaupIISfvbEPwCqzLZnJKdL5uWl4ZtJDkag9tQfezA0VBCHdMW61OR4lZF9xn+uDz7lNS f9sucu2NDICf9pw7fak5b2P1EkK2TRx86oqfVANkKaxSRWz0GaX/UypZNGQh0RahYWktJaT AuikxfvsvAZeXMnLtzWKg== X-UI-Out-Filterresults: notjunk:1;V01:K0:J2rR8v95H9Q=:Qgp5qauKqXqL9D5an4kQFN p3lxjiEIlX6u0eR82zjpMmahNMq0kLtkLniO6UybVhYq7nEKaKvu369cGlomWLzrzE2gxyBBf 3POd9yzJeIF3gm5ihPnY7+dBBo4cRWL+UWPJS+qEHJHc7tcHZ/4mrJzYDTqHGGakd9lg4k1n7 6AA+YujOZir2YiwoBe51NRbpBBvbim6Ys+gpFlifMfff3h5K6intQyz//Dvsg5obHZdNcqepg dQukjGm4DxS14lm0o1CY9PzNWWgHd201Ek+KS4rKh7UVgAFTSzTvAz1mW+wvD7s5uqGudOKfy LvP2pPFSLEPGN9VzqpIZbGCwG3vefQovKukssEckd+FrHjHEUFzCw3XgDgxDsMmnS336WTKb3 /HPwUWpxyMGfUXl3joknKNwGIBirViHrHdC9fcYQ8andETvGImuYTMhWa4YFVBfi5UU0RmMw7 NBfVTAzGh9x8Dhcgp0gV9DERhFZmX60iTd4VFk84U3CRDgMoeJHdO3EiJoM65mPosI/Oncai5 msMhLYjKfl1A/5cRtk1744Kf0IsLYGMXsrPtBLZht+69YOylrIgr1gkuRgcbltubGyyFuik66 ld8VoNJYrJxoiYfhm0KMY30EczaQdo42q3Os7kNyEbO6JrflS+0Nws72qV8g9x5znNpSpr8gE BFbdmIQt7G1pslscz3l+rSdmY0cr3uqErJBEvvN6mQNyb1mGTeAa0MTRsbaYu/9ISdhK2uMMj jDLBrp7Kcb82+C401tHYvoYfmtWjff7qnNio0Eblo/UUNCgBLQK/WmWzTDEfkt8LydykgvpF X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 212.227.15.15 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:221170 Archived-At: > The code with undefined behavior is in delete_frame, after its 3rd use > of FOR_EACH_FRAME. This loop head is of the form 'FOR_EACH_FRAME > (tail, frame1) ...' and the code after the loop assumes that frame1 is > initialized, an assumption that is false if Vframe_list is nil. Sorry for being completely dense but eassume (CONSP (Vframe_list)); now means that we can assume that `frame-list' is non-empty. Isn't that assumption incorrect in the scenario of the bug we're discussing here? >> Neither next_frame nor prev_frame exhibit such behavior IMO. > > That's right. However, commit 8720f601e715e5f1d41f7cf863a525a1cc1bc12c > removed these functions' assertions that frame-list is non-nil, so I > thought it wise to resurrect them. I don't think that these assertions did any good and would remove them at least on master. martin