From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <zsh-workers-return-37072-mason-zsh=primenet.com.au@zsh.org>
Received: (qmail 23993 invoked by alias); 6 Nov 2015 11:12:26 -0000
Mailing-List: contact zsh-workers-help@zsh.org; run by ezmlm
Precedence: bulk
X-No-Archive: yes
List-Id: Zsh Workers List <zsh-workers.zsh.org>
List-Post: <mailto:zsh-workers@zsh.org>
List-Help: <mailto:zsh-workers-help@zsh.org>
X-Seq: 37072
Received: (qmail 19712 invoked from network); 6 Nov 2015 11:12:26 -0000
X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on f.primenet.com.au
X-Spam-Level: 
X-Spam-Status: No, score=-1.0 required=5.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED,
	FREEMAIL_FROM,NML_ADSP_CUSTOM_MED autolearn=no autolearn_force=no
	version=3.4.0
X-Injected-Via-Gmane: http://gmane.org/
To: zsh-workers@zsh.org
From: Christian Neukirchen <chneukirchen@gmail.com>
Subject: Inconsistency with SHWORDSPLIT and leading spaces
Date: Fri, 06 Nov 2015 11:54:49 +0100
Message-ID: <87a8qr75za.fsf@gmail.com>
Mime-Version: 1.0
Content-Type: text/plain
X-Complaints-To: usenet@ger.gmane.org
X-Gmane-NNTP-Posting-Host: host53-2.natpool.mwn.de
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux)

Hi,

I noticed the following different behavior trying to use zsh as /bin/sh:

juno ~% dash -c 'x=foo; echo x${x:+ $x}' 
x foo
juno ~% bash -c 'x=foo; echo x${x:+ $x}' 
x foo
juno ~% mksh -c 'x=foo; echo x${x:+ $x}' 
x foo
juno ~% ksh -c 'x=foo; echo x${x:+ $x}' 
x foo
juno ~% zsh -c 'x=foo; echo x${x:+ $x}' 
x foo
juno ~% zsh -c 'emulate -L sh; x=foo; echo x${x:+ $x}'           
xfoo
juno ~% zsh -c 'emulate -L ksh; x=foo; echo x${x:+ $x}' 
xfoo
juno ~% zsh -c 'setopt shwordsplit; x=foo; echo x${x:+ $x}' 
xfoo

zsh 5.1.1 (x86_64-unknown-linux-gnu)
zsh-5.1.1-0-g68405f3

It's not clear to me whether this is *actually* POSIX-nonconformant, but
it's at least surprising compared to the other POSIX-compatible shells.

Thanks,
-- 
Christian Neukirchen  <chneukirchen@gmail.com>  http://chneukirchen.org