From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.emacs.gnus.general/32949 Path: main.gmane.org!not-for-mail From: prj@po.cwru.edu (Paul Jarc) Newsgroups: gmane.emacs.gnus.general Subject: Re: (concat "/dir/name/" "foo") --> (expand-file-name "foo" "/dir/name/") Date: 23 Oct 2000 11:29:59 -0400 Sender: owner-ding@hpc.uh.edu Message-ID: References: <200010161812.TAA25555@djlvig.dl.ac.uk> <200010181755.SAA08846@djlvig.dl.ac.uk> <200010221600.RAA25651@djlvig.dl.ac.uk> NNTP-Posting-Host: coloc-standby.netfonds.no Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable X-Trace: main.gmane.org 1035169145 22618 80.91.224.250 (21 Oct 2002 02:59:05 GMT) X-Complaints-To: usenet@main.gmane.org NNTP-Posting-Date: Mon, 21 Oct 2002 02:59:05 +0000 (UTC) Return-Path: Original-Received: from spinoza.math.uh.edu (spinoza.math.uh.edu [129.7.128.18]) by mailhost.sclp.com (Postfix) with ESMTP id C1F76D051F for ; Mon, 23 Oct 2000 11:35:10 -0400 (EDT) Original-Received: from sina.hpc.uh.edu (lists@Sina.HPC.UH.EDU [129.7.3.5]) by spinoza.math.uh.edu (8.9.1/8.9.1) with ESMTP id KAB05871; Mon, 23 Oct 2000 10:30:50 -0500 (CDT) Original-Received: by sina.hpc.uh.edu (TLB v0.09a (1.20 tibbs 1996/10/09 22:03:07)); Mon, 23 Oct 2000 10:30:14 -0500 (CDT) Original-Received: from mailhost.sclp.com (postfix@66-209.196.61.interliant.com [209.196.61.66] (may be forged)) by sina.hpc.uh.edu (8.9.3/8.9.3) with ESMTP id KAA16820 for ; Mon, 23 Oct 2000 10:30:00 -0500 (CDT) Original-Received: from multivac.student.cwru.edu (multivac.STUDENT.CWRU.Edu [129.22.239.69]) by mailhost.sclp.com (Postfix) with SMTP id 54EB2D051F for ; Mon, 23 Oct 2000 11:30:22 -0400 (EDT) Original-Received: (qmail 28372 invoked by uid 500); 23 Oct 2000 15:30:21 -0000 Mail-Followup-To: ding@gnus.org Original-To: ding@gnus.org In-Reply-To: Kai.Grossjohann@CS.Uni-Dortmund.DE's message of "23 Oct 2000 09:52:29 +0200" Original-Lines: 24 User-Agent: Gnus/5.0807 (Gnus v5.8.7) Emacs/20.7 Precedence: list X-Majordomo: 1.94.jlt7 Xref: main.gmane.org gmane.emacs.gnus.general:32949 X-Report-Spam: http://spam.gmane.org/gmane.emacs.gnus.general:32949 Kai.Grossjohann@CS.Uni-Dortmund.DE (Kai Gro=DFjohann) writes: > On 22 Oct 2000, Paul Jarc wrote: > > A mischevious, badly-written, or maybe just an unconventional > > handler might give an expanded name that would, when re-expanded, > > give a different name. But this probably doesn't happen in most > > normal situations. >=20 > So it's a bug when expand-file-name fails to be idempotent? In such a case, it's a bug to expand an already-expanded name, yes. I don't know whether any code actually has this bug. > Hm. Maybe it isn't too bad after all, but one has to be very careful > to say (concat (file-name-as-directory D) F), not just (concat D F). > But I think you were saying that file-name-as-directory might not be > idempotent, either, right? So we have just shifted the problem. True, if you don't know whether D is as-directory to begin with. But expand-file-name does other things as well; file-name-as-directory does only one simple thing, so it has a better chance of being idempotent, even if only by accident. paul