From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#17330: files.el cd-absolute overcome false negative from file-executable-p Date: Thu, 08 May 2014 19:18:13 +0300 Message-ID: <838uqcw8fu.fsf@gnu.org> References: <83ha51wj35.fsf@gnu.org> <536B1C56.4040307@bluewin.ch> Reply-To: Eli Zaretskii NNTP-Posting-Host: plane.gmane.org X-Trace: ger.gmane.org 1399565970 8356 80.91.229.3 (8 May 2014 16:19:30 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 8 May 2014 16:19:30 +0000 (UTC) Cc: 17330@debbugs.gnu.org To: Philip Hodges Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Thu May 08 18:19:23 2014 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1WiR2T-0004sX-NI for geb-bug-gnu-emacs@m.gmane.org; Thu, 08 May 2014 18:19:17 +0200 Original-Received: from localhost ([::1]:48234 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WiR2T-0004oN-46 for geb-bug-gnu-emacs@m.gmane.org; Thu, 08 May 2014 12:19:17 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:46508) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WiR2K-0004ip-RR for bug-gnu-emacs@gnu.org; Thu, 08 May 2014 12:19:13 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WiR2E-000215-GK for bug-gnu-emacs@gnu.org; Thu, 08 May 2014 12:19:08 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:38822) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WiR2E-00020y-Cu for bug-gnu-emacs@gnu.org; Thu, 08 May 2014 12:19:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.80) (envelope-from ) id 1WiR2D-0000L2-MM for bug-gnu-emacs@gnu.org; Thu, 08 May 2014 12:19:01 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Thu, 08 May 2014 16:19:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 17330 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: moreinfo Original-Received: via spool by 17330-submit@debbugs.gnu.org id=B17330.13995658921233 (code B ref 17330); Thu, 08 May 2014 16:19:01 +0000 Original-Received: (at 17330) by debbugs.gnu.org; 8 May 2014 16:18:12 +0000 Original-Received: from localhost ([127.0.0.1]:56173 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1WiR1P-0000Jo-6Y for submit@debbugs.gnu.org; Thu, 08 May 2014 12:18:11 -0400 Original-Received: from mtaout22.012.net.il ([80.179.55.172]:40051) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1WiR1L-0000JP-MO for 17330@debbugs.gnu.org; Thu, 08 May 2014 12:18:08 -0400 Original-Received: from conversion-daemon.a-mtaout22.012.net.il by a-mtaout22.012.net.il (HyperSendmail v2007.08) id <0N5900E00JROYO00@a-mtaout22.012.net.il> for 17330@debbugs.gnu.org; Thu, 08 May 2014 19:18:01 +0300 (IDT) Original-Received: from HOME-C4E4A596F7 ([87.69.4.28]) by a-mtaout22.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0N5900E2SJY0JO70@a-mtaout22.012.net.il>; Thu, 08 May 2014 19:18:01 +0300 (IDT) In-reply-to: <536B1C56.4040307@bluewin.ch> X-012-Sender: halo1@inter.net.il X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.15 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 140.186.70.43 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.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:88778 Archived-At: > Date: Thu, 08 May 2014 07:55:34 +0200 > From: Philip Hodges > CC: rgm@gnu.org, 17330@debbugs.gnu.org > > > I prefer to solve the problem rather than ask users work around it. > > So when can we reasonably expect a guarantee of no more false negatives > for users of 24.3 without having to inspect the fileio.c and files.el > and reinvent an undocumented workaround? Emacs 24.3 was released more than a year ago, so fixing this in that version might be possible only by some suitable change to the directory's security descriptor outside of Emacs (if such a change is possible). But we can hope to fix this in future versions of Emacs. > It will be great if you really can *solve* the problem, even just for > this one particular scenario. I already suggested a pathological > counterexample. Other sources mentioned do indicate that it is > impossible to solve it reliably in general. But perhaps it will be > enough in practice. If we understand the problem in enough detail, we might find a solution of some sort. > Only the positive outcome of file-executable-p is documented as "this > means you can access files in that directory". The negative outcome is > not explicitly documented as meaning you cannot, yet that is how callers > are interpreting it. So there is clearly scope for rewriting the > documentation and changing the callers' logic to match. That is a different, although related discussion. Arguably, if a directory is not accessible by me, Emacs had better not attempt that, even if it might succeed, and instead leave it for the user to fix the access rights by other means. But even if we accept your views on this, it is better to try to solve the problem than work around it.