From owner-svn-src-head@freebsd.org  Fri Apr 28 16:16:24 2017
Return-Path: <owner-svn-src-head@freebsd.org>
Delivered-To: svn-src-head@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id 28D4ED54ADD;
 Fri, 28 Apr 2017 16:16:24 +0000 (UTC)
 (envelope-from jilles@FreeBSD.org)
Received: from repo.freebsd.org (repo.freebsd.org
 [IPv6:2610:1c1:1:6068::e6a:0])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id D4FAE1A63;
 Fri, 28 Apr 2017 16:16:23 +0000 (UTC)
 (envelope-from jilles@FreeBSD.org)
Received: from repo.freebsd.org ([127.0.1.37])
 by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id v3SGGMXM036816;
 Fri, 28 Apr 2017 16:16:22 GMT (envelope-from jilles@FreeBSD.org)
Received: (from jilles@localhost)
 by repo.freebsd.org (8.15.2/8.15.2/Submit) id v3SGGMH5036815;
 Fri, 28 Apr 2017 16:16:22 GMT (envelope-from jilles@FreeBSD.org)
Message-Id: <201704281616.v3SGGMH5036815@repo.freebsd.org>
X-Authentication-Warning: repo.freebsd.org: jilles set sender to
 jilles@FreeBSD.org using -f
From: Jilles Tjoelker <jilles@FreeBSD.org>
Date: Fri, 28 Apr 2017 16:16:22 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
 svn-src-head@freebsd.org
Subject: svn commit: r317559 - head/bin/sh
X-SVN-Group: head
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-BeenThere: svn-src-head@freebsd.org
X-Mailman-Version: 2.1.23
Precedence: list
List-Id: SVN commit messages for the src tree for head/-current
 <svn-src-head.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/svn-src-head>,
 <mailto:svn-src-head-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-head/>
List-Post: <mailto:svn-src-head@freebsd.org>
List-Help: <mailto:svn-src-head-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/svn-src-head>,
 <mailto:svn-src-head-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 28 Apr 2017 16:16:24 -0000

Author: jilles
Date: Fri Apr 28 16:16:22 2017
New Revision: 317559
URL: https://svnweb.freebsd.org/changeset/base/317559

Log:
  sh: Simplify handling of newlines in command substitution.
  
  Unless we need to split on newlines, just append them as normal and remove
  them at the end.

Modified:
  head/bin/sh/expand.c

Modified: head/bin/sh/expand.c
==============================================================================
--- head/bin/sh/expand.c	Fri Apr 28 15:38:34 2017	(r317558)
+++ head/bin/sh/expand.c	Fri Apr 28 16:16:22 2017	(r317559)
@@ -462,6 +462,7 @@ expbackq(union node *cmd, int quoted, in
 	int quotes = flag & (EXP_GLOB | EXP_CASE);
 	size_t nnl;
 	const char *ifs;
+	int startloc;
 
 	INTOFF;
 	p = grabstackstr(dest);
@@ -469,6 +470,7 @@ expbackq(union node *cmd, int quoted, in
 	ungrabstackstr(p, dest);
 
 	p = in.buf;
+	startloc = dest - stackblock();
 	nnl = 0;
 	if (!quoted && flag & EXP_SPLIT)
 		ifs = ifsset() ? ifsval() : " \t\n";
@@ -490,31 +492,24 @@ expbackq(union node *cmd, int quoted, in
 		lastc = *p++;
 		if (lastc == '\0')
 			continue;
-		if (lastc == '\n') {
-			nnl++;
-		} else {
-			if (nnl > 0) {
-				if (strchr(ifs, '\n') != NULL) {
-					NEXTWORD('\n', flag, dest, dst);
-					nnl = 0;
-				} else {
-					CHECKSTRSPACE(nnl + 2, dest);
-					while (nnl > 0) {
-						nnl--;
-						USTPUTC('\n', dest);
-					}
-				}
-			}
-			if (strchr(ifs, lastc) != NULL)
+		if (nnl > 0 && lastc != '\n') {
+			NEXTWORD('\n', flag, dest, dst);
+			nnl = 0;
+		}
+		if (strchr(ifs, lastc) != NULL) {
+			if (lastc == '\n')
+				nnl++;
+			else
 				NEXTWORD(lastc, flag, dest, dst);
-			else {
-				CHECKSTRSPACE(2, dest);
-				if (quotes && syntax[(int)lastc] == CCTL)
-					USTPUTC(CTLESC, dest);
-				USTPUTC(lastc, dest);
-			}
+		} else {
+			CHECKSTRSPACE(2, dest);
+			if (quotes && syntax[(int)lastc] == CCTL)
+				USTPUTC(CTLESC, dest);
+			USTPUTC(lastc, dest);
 		}
 	}
+	while (dest > stackblock() + startloc && STTOPC(dest) == '\n')
+		STUNPUTC(dest);
 
 	if (in.fd >= 0)
 		close(in.fd);