From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Michael Albinus Newsgroups: gmane.emacs.devel Subject: Re: master 9dc306b1: Improve reporting of I/O, access errors Date: Wed, 18 Sep 2019 09:41:09 +0200 Message-ID: <875zlqgiga.fsf@gmx.de> References: <20190918022442.11082.40975@vcs0.savannah.gnu.org> <20190918022444.103AC207F5@vcs0.savannah.gnu.org> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="79520"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.0.50 (gnu/linux) Cc: Paul Eggert To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed Sep 18 09:44:14 2019 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iAUdK-000Kai-5x for ged-emacs-devel@m.gmane.org; Wed, 18 Sep 2019 09:44:14 +0200 Original-Received: from localhost ([::1]:55380 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iAUdI-0005TG-Nf for ged-emacs-devel@m.gmane.org; Wed, 18 Sep 2019 03:44:12 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:42027) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iAUaf-0005T3-UP for emacs-devel@gnu.org; Wed, 18 Sep 2019 03:41:31 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iAUae-0004fn-Sm for emacs-devel@gnu.org; Wed, 18 Sep 2019 03:41:29 -0400 Original-Received: from mout.gmx.net ([212.227.17.22]:35479) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1iAUae-0004eR-GW for emacs-devel@gnu.org; Wed, 18 Sep 2019 03:41:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1568792474; bh=8wQS+GIXoo34bYIi07qBqc8yCZuRX12NUrOeQixzmaM=; h=X-UI-Sender-Class:From:To:Cc:Subject:References:Date:In-Reply-To; b=KBnphORXfX6cFe8C2AR/N81JahfwuS8I/VaMNr1P+R6VfBEbv8kndHlZJEXw6HwgP NiB15f9R4SApU/tG+3h0BGXn5aJBfi9Uqo4dFDzA6Vu3dYdlbpIjMQIaohpfaVFcuH FIikmMetTpKFEJO85dun5zYbT9MrYWjMcdRoz1Rk= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Original-Received: from detlef.gmx.de ([212.91.243.210]) by mail.gmx.com (mrgmx103 [212.227.17.168]) with ESMTPSA (Nemesis) id 0MJBn4-1iDEPI0FBa-002rg8; Wed, 18 Sep 2019 09:41:14 +0200 In-Reply-To: <20190918022444.103AC207F5@vcs0.savannah.gnu.org> (Paul Eggert's message of "Tue, 17 Sep 2019 22:24:43 -0400 (EDT)") X-Provags-ID: V03:K1:eH0A8GI3CIZ7pCpPgCg0wD9m+HmBjLtG0TtNxZK1opNW90GksAw tLnyxQVyUQs/h2C/44awzEK/VCY0M9rUXgpba2gNN2xaKzo+ihe3WTZ1ahs9EB8gHDXbFkp +IRGXtQJEmYSw1z1pC1KvlIouG3PJvHx92fcA8esL6+FD6Yckzqr3zv19qMUgJtHAdNO+B9 kTe8WMhPdcB8y3ZWpUHuw== X-UI-Out-Filterresults: notjunk:1;V03:K0:dLvsLUPCrTQ=:Uiw0KQJKUZwk1OqTLY+yF7 14dEskxyfjUJrPIPkMCc33e+iLTcm8V4AqVzW+V8e+TU1OVfhg2RrK6Oq5Wo4HXdThiexq0hl /Ak2186NRwBgxzxNMOh0Upn16BRypOO+etD+VDsPgo4eW835SXKqvQddI4Ah2AB3vhpd5RKBp AHl8qXEFHFSCk7nKhruZWpIkbxaqXnwV9V9mK1zm21R8aOcv4iV2CS4wVWNYD8cjLVSnarI9s SJSpiMJ3bhOoIVYlYNt5hJ+mtaTBbfuC/o/Ggz/yi0fXcBoCHb66QnCjDn5+5ZZsW8KNf1S6+ xSrn3dkOQWxESWa3G9XwVd2MctJ2kXgqvX5xgY626LwAbylNctr6K5G86gJ19hh6hkIwL4hor 5U9CGJsfib8ldsU7WeHE4Qt2tk1C71n+L706WYyQ4EHf7Pkd3AuQzxk+GYjhDQvB/1dtgOr+v rENWPCd5PqNpawDgBfK1PRDWrOzaaGE29oTgEaYhILYB57LqUcj3ZhCoaVqU2nGr1LHycAbeO FPotqugBiSPKBMkp4btPZo9ML0/+rUlwZCWDb2PqBrx3y7epTj9mSCRKxr2TEU42YQWIs3HRZ BxkO+9aTOpq8Ynk91yUWfsDUAnRmCjTX4/pEbEaSH0gV7wcopaw+EW/h7Mf7l1FWZUMcSaqUM P+zRVTcT7703bfU0xghMC1ryMW1DnH1HQ4ejP2AP7qd+3PViTZl5fpqur4+2KBGvTm5HAjwx6 pN5UZbQT1akxWopEM2KFA4Wer42cTHheASrB50/deXJTgc11u+tOz+WMexawsdGpjGK5tGB/ X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 212.227.17.22 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 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:240124 Archived-At: eggert@cs.ucla.edu (Paul Eggert) writes: Hi, > diff --git a/etc/NEWS b/etc/NEWS > index 9aec8da..dce4903 100644 > --- a/etc/NEWS > +++ b/etc/NEWS > @@ -2005,6 +2005,16 @@ file name if there is no user named "foo". > ** The FILENAME argument to 'file-name-base' is now mandatory and no > longer defaults to 'buffer-file-name'. > > ++++ > +** File metadata primitives now signal an error if I/O, access, or > +other serious errors prevent them from determining the result. > +Formerly, these functions often (though not always) returned nil. > +For example, if the directory /etc/firewalld is not searchable, > +(file-symlink-p "/etc/firewalld/firewalld.conf") now signals an error > +instead of returning nil, because file-symlink-p cannot determine > +whether a symbolic link exists there. These functions still behave as > +before if the only problem is that the file does not exist. That is a serious API change, and I fear it will break existing code. For example, Tramp trusts on file-attributes returning nil, when a file does not exist or is not accessible for whatever reason. This is true also for local files. Furthermore, Tramp does not report anything but nil if a remote file is not accessible due to I/O errors. So the promise of this change cannot be kept for all situations. I didn't follow the discussion for this, but is it really worth to break existing code? (And at least, this paragraph belongs to "Incompatible Lisp Changes in Emacs 27.1" in NEWS) Best regards, Michael.