DMARC-Filter: OpenDMARC Filter v1.4.2 delorie.com 51K086bS003723
Authentication-Results: delorie.com; dmarc=pass (p=none dis=none) header.from=cygwin.com
Authentication-Results: delorie.com; spf=pass smtp.mailfrom=cygwin.com
DKIM-Filter: OpenDKIM Filter v2.11.0 delorie.com 51K086bS003723
Authentication-Results: delorie.com;
	dkim=pass (1024-bit key, unprotected) header.d=cygwin.com header.i=@cygwin.com header.a=rsa-sha256 header.s=default header.b=sHk9lIGu
X-Recipient: archive-cygwin AT delorie DOT com
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 5A5E63858C50
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cygwin.com;
	s=default; t=1740010084;
	bh=+Wm4LtIfQCJ70owhpZcZOWoh3rcViLfePCgC3CMt6dI=;
	h=Date:To:cc:Subject:In-Reply-To:References:List-Id:
	 List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe:
	 From:Reply-To:From;
	b=sHk9lIGuO3wOkSIzj+RG6xT2SJqi/Xf6lHxWwLSGX6XfMYzaMeuMnmoGAM5H14TP9
	 N7kao4Y1MMgJXq2T3E99twolupRun2E0wk4Upfj3Mowr4Ve/A2XKy2LYmvxpR88XOy
	 JjFubirlCeeL0opNSavE3AezkmbKZHDPPCDpDg8Q=
X-Original-To: cygwin AT cygwin DOT com
Delivered-To: cygwin AT cygwin DOT com
DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 9E2663858C42
ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 9E2663858C42
ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1740009994; cv=none;
 b=omADZN2a9bYUc+SBZuwGVwS5b5Fb1tVzo2w7dZH26l74y+YWeKj44p4SZR95hcK+qboe9+vVcp2SH4msaDYqKbN6jdyZ30UN80rFHpNdhkEMMuGPoKpmxBcs6Z2aLdBMpxCvPSXUm8qT9oXlc0mfz6dAUfZcVGPdnCFzxzqwwAg=
ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key;
 t=1740009994; c=relaxed/simple;
 bh=nYWz0+Ie09D43FgTdFq3GjvL3IWKnrJpW9xC11Cr/m4=;
 h=DKIM-Signature:Date:From:To:Subject:Message-ID:MIME-Version;
 b=B5C9Ipc4WkTITM/qKIx4qHaUby6hQkbqqqOscCPZJUUrs7zQSHvx9YlefLjUvMJuvwQ05qzOze69y7uQV3L6SQ6DmQn7rkbuojbAGJ4F2roN8EOTEZBJ0IrEkqtFnLrNHO4POXrESuH3sOJd231JeKlOZw7MP1tyf+W63LMHbVY=
ARC-Authentication-Results: i=1; server2.sourceware.org
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 9E2663858C42
Date: Wed, 19 Feb 2025 16:06:34 -0800 (PST)
X-X-Sender: jeremyd AT resin DOT csoft DOT net
To: Roland Mainz <roland DOT mainz AT nrubsig DOT org>
cc: cygwin AT cygwin DOT com
Subject: Re: Pipes/fifos/sockets&&|mmap()|'ed output files in POSIX shell
 x=$(cmd) and x=${ cmd ; } statements... / was: Re: [regression-3.6] Pipe
 between Cygwin and non Cygwin (CRT/URT) randomly loses characters
In-Reply-To: <CAKAoaQ=1QexEh_gzyRPpKsdJ4T4qz3BVM5YgXfnefC2YVcaUOA@mail.gmail.com>
Message-ID: <245ac4e5-c7c4-106a-591f-18536815cec8@jdrake.com>
References: <CALXu0Ue6z-QgfG3o7waBQ=n17xhAQAAH_Lx+0tyXGsKzhLMmtg AT mail DOT gmail DOT com>
 <20250219162341 DOT 6c907a00b9bd7b0ae6f78c93 AT nifty DOT ne DOT jp>
 <CAKAoaQ=1QexEh_gzyRPpKsdJ4T4qz3BVM5YgXfnefC2YVcaUOA AT mail DOT gmail DOT com>
MIME-Version: 1.0
X-BeenThere: cygwin AT cygwin DOT com
X-Mailman-Version: 2.1.30
Precedence: list
List-Id: General Cygwin discussions and problem reports <cygwin.cygwin.com>
List-Unsubscribe: <https://cygwin.com/mailman/options/cygwin>,
 <mailto:cygwin-request AT cygwin DOT com?subject=unsubscribe>
List-Archive: <https://cygwin.com/pipermail/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-request AT cygwin DOT com?subject=help>
List-Subscribe: <https://cygwin.com/mailman/listinfo/cygwin>,
 <mailto:cygwin-request AT cygwin DOT com?subject=subscribe>
From: Jeremy Drake via Cygwin <cygwin AT cygwin DOT com>
Reply-To: Jeremy Drake <cygwin AT jdrake DOT com>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Errors-To: cygwin-bounces~archive-cygwin=delorie DOT com AT cygwin DOT com
Sender: "Cygwin" <cygwin-bounces~archive-cygwin=delorie DOT com AT cygwin DOT com>

On Thu, 20 Feb 2025, Roland Mainz via Cygwin wrote:

> > > Same happens with dash and ksh93.
>
> And THAT statement is BAD, because it means basic shell functionality
> is broken, affecting dash/bash/ksh93 - reading that IMO means Cygwin
> has a problem in the pipe/fifo code... ;-(
>
> Best way forward is to grab the shell testsuite (e.g. both bash and
> ast-ksh/ksh93 ship with test suites), and run the pipe/command
> substitution tests.

This report has to do with the case where the other end of the pipe is a
native Windows program (rather than another Cygwin program), and that
case is (at least used to be) different in the Cygwin pipe code.  It's
doubtful a UNIX shell test suite would exercise that codepath.

BTW, I would not be at all surprised if the following were related
somehow:
https://github.com/msys2/msys2-runtime/issues/230
https://github.com/git-for-windows/msys2-runtime/pull/75


-- 
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple