From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Dave Abrahams Newsgroups: gmane.emacs.bugs Subject: bug#12351: 24.1; parse-colon-path turns empty paths into nil Date: Sun, 30 Dec 2012 14:53:44 -0500 Message-ID: References: NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1356897250 21578 80.91.229.3 (30 Dec 2012 19:54:10 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sun, 30 Dec 2012 19:54:10 +0000 (UTC) Cc: 12351@debbugs.gnu.org To: Glenn Morris Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Sun Dec 30 20:54:25 2012 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 1TpOxi-00087b-A0 for geb-bug-gnu-emacs@m.gmane.org; Sun, 30 Dec 2012 20:54:22 +0100 Original-Received: from localhost ([::1]:38676 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TpOxT-00072k-Kv for geb-bug-gnu-emacs@m.gmane.org; Sun, 30 Dec 2012 14:54:07 -0500 Original-Received: from eggs.gnu.org ([208.118.235.92]:53227) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TpOxP-00072A-6T for bug-gnu-emacs@gnu.org; Sun, 30 Dec 2012 14:54:05 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TpOxI-0001S0-Vg for bug-gnu-emacs@gnu.org; Sun, 30 Dec 2012 14:54:03 -0500 Original-Received: from debbugs.gnu.org ([140.186.70.43]:55260) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TpOxI-0001Rw-SP for bug-gnu-emacs@gnu.org; Sun, 30 Dec 2012 14:53:56 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.72) (envelope-from ) id 1TpOyM-0003c9-50 for bug-gnu-emacs@gnu.org; Sun, 30 Dec 2012 14:55:02 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Dave Abrahams Original-Sender: debbugs-submit-bounces@debbugs.gnu.org Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sun, 30 Dec 2012 19:55:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 12351 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 12351-submit@debbugs.gnu.org id=B12351.135689729513878 (code B ref 12351); Sun, 30 Dec 2012 19:55:02 +0000 Original-Received: (at 12351) by debbugs.gnu.org; 30 Dec 2012 19:54:55 +0000 Original-Received: from localhost ([127.0.0.1]:37278 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.72) (envelope-from ) id 1TpOyF-0003bn-CM for submit@debbugs.gnu.org; Sun, 30 Dec 2012 14:54:55 -0500 Original-Received: from mail-vb0-f43.google.com ([209.85.212.43]:63710) by debbugs.gnu.org with esmtp (Exim 4.72) (envelope-from ) id 1TpOyD-0003bf-1c for 12351@debbugs.gnu.org; Sun, 30 Dec 2012 14:54:54 -0500 Original-Received: by mail-vb0-f43.google.com with SMTP id fs19so12145259vbb.16 for <12351@debbugs.gnu.org>; Sun, 30 Dec 2012 11:53:47 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-received:from:to:cc:subject:references:date:in-reply-to :message-id:user-agent:mime-version:content-type:x-gm-message-state; bh=lJktqUhn3HF91Q6tZZycb609hXUyV4gZs0yw6+xjo+Y=; b=Vv0rFIR+1AB5U2KOGgK8qnBdkQnyiXowfh82KGQo9oM5ymjmzA3U2G3EeRaOvIKAOf wq6LB0xti5jKSTiPKyLbVJVUVKfKiJ27Hd5iJ4Y9SZrbnXBNI+KG27psU0UYiCIbCkmp kS/wRY3eDVk5lCL5YFddBPm7hPA8kv0ws7b/phWtc+bUbrI5vxMFHr4ZErVDc/Tz2Kp3 ub7ul+g8oq9SFl4dFeWsuqsannLaTdLpFCf2qWheMXWoo3WH1lV08ixmNv1sB103mbF4 38sP+BFKhLTpuU3qXPAwdc45fHDWIGbAaHmmIp3/BgC4+s+2SRgMRzSEYkuYcdFxa+K9 RIMg== X-Received: by 10.52.18.147 with SMTP id w19mr53292462vdd.94.1356897226960; Sun, 30 Dec 2012 11:53:46 -0800 (PST) Original-Received: from pluto.boostpro.com (207-172-223-249.c3-0.smr-ubr3.sbo-smr.ma.static.cable.rcn.com. [207.172.223.249]) by mx.google.com with ESMTPS id di16sm36335861vdb.11.2012.12.30.11.53.45 (version=TLSv1/SSLv3 cipher=OTHER); Sun, 30 Dec 2012 11:53:46 -0800 (PST) Original-Received: by pluto.boostpro.com (Postfix, from userid 501) id A9F619AC073; Sun, 30 Dec 2012 14:53:44 -0500 (EST) In-Reply-To: (Glenn Morris's message of "Sun, 30 Dec 2012 13:52:11 -0500") User-Agent: Gnus/5.130006 (Ma Gnus v0.6) Emacs/24.2 (darwin) X-Gm-Message-State: ALoCoQngrZD66m+Vemv8Yqvs3yTQ8pJXL/+q+CM4//qz2sSLb4XUSJRVp11DLPKlwuzJnSvS9ih6 X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.13 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6.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:69198 Archived-At: on Sun Dec 30 2012, Glenn Morris wrote: > Dave Abrahams wrote: > >> (parse-colon-path ":") yields (nil nil) but there's nothing in the >> docstring to indicate that empty path entries will get turned into nil. >> Either the docstring needs to be updated, or parse-colon-path should >> return (delq nil cd-list). > > Making a change equivalent to the latter has caused > > http://debbugs.gnu.org/13296 > > Obviously we need the nils to remain, so I will put them back and just > mention that empty elements return nil. It's not worth handling the > minor aesthetic annoyance of (nil nil) specially. FWIW, I disagree. IMO you should at least consider fixing eshell and any other things that break because of this change. This discontinuity in behavior is not merely aesthetic; it makes parse-colon-path difficult to use correctly and leads to hard-to-find bugs in any code that fails to account for the possible nils. -- Dave Abrahams BoostPro Computing Software Development Training http://www.boostpro.com Clang/LLVM/EDG Compilers C++ Boost