From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: emacs-26 8f18d12: Improve documentation of decoding into a unibyte buffer Date: Tue, 28 May 2019 22:35:44 +0300 Message-ID: <83imtuz81b.fsf@gnu.org> References: <20190525191039.14136.23307@vcs0.savannah.gnu.org> <20190525191040.CCD6C207F5@vcs0.savannah.gnu.org> <88F01F35-BE24-4F6E-B832-64AFE28CD06B@gnu.org> <83woiazjyo.fsf@gnu.org> <83muj6z9s4.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="256637"; mail-complaints-to="usenet@blaine.gmane.org" Cc: emacs-devel@gnu.org To: monnier@iro.umontreal.ca Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Tue May 28 21:45:27 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 (TLS1.0:RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1hVi2H-0014cP-07 for ged-emacs-devel@m.gmane.org; Tue, 28 May 2019 21:45:25 +0200 Original-Received: from localhost ([127.0.0.1]:41714 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hVi2F-0004Od-N5 for ged-emacs-devel@m.gmane.org; Tue, 28 May 2019 15:45:23 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:38411) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hVhsu-0005Mj-Oe for emacs-devel@gnu.org; Tue, 28 May 2019 15:35:45 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:37887) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hVhso-0005I7-JC; Tue, 28 May 2019 15:35:41 -0400 Original-Received: from [176.228.60.248] (port=3751 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1hVhsn-0007ip-CK; Tue, 28 May 2019 15:35:38 -0400 In-reply-to: <83muj6z9s4.fsf@gnu.org> (message from Eli Zaretskii on Tue, 28 May 2019 21:58:03 +0300) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] 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:237123 Archived-At: > Date: Tue, 28 May 2019 21:58:03 +0300 > From: Eli Zaretskii > Cc: emacs-devel@gnu.org > > > From: Stefan Monnier > > Cc: emacs-devel@gnu.org > > Date: Tue, 28 May 2019 13:43:47 -0400 > > > > > (let* ((str1 (string-as-multibyte (string char))) > > > (str2 (string-as-multibyte (string char char))) > > > > Why on earth do we call string-as-multibyte here? AFAIK, the only cases > > where `string` returns a unibyte string is when char <128 (it could make > > sense to also do that for char ≥128 and <160, but we don't seem to do > > that currently) and these are better turned into multibyte via > > string-TO-unibyte (tho here we don't even need that, since the unibyte > > string works just as well for what we do) than string-AS-unibyte. > > > > I think this is an error. The patch below seems in order. > > I'm not sure. Be sure to read the comments about the tricky business > of this function, and the method it employs to solve it, and be sure > you understand all of the subtleties there. Btw, that function has a bug: (encode-coding-char ?a 'ebcdic-us) => "a" It assumes that any ASCII character is encoded into itself, i.e. that every coding-system is ASCII-compatible, which is false.