From 131df9fa5f7c139ca02ca9026e386b56af17aed0 Mon Sep 17 00:00:00 2001
From: jjohnstn <jjohnstn>
Date: Tue, 22 Aug 2006 20:30:37 +0000
Subject: [PATCH] 2006-08-22  Eric Blake  <ebb9@byu.net>

        * libc/posix/popen.c (popen): Don't close output end of pipe in
        child if stdout was closed on entry.
        [HAVE_FCNTL]: In parent, mark file as close-on-exec, per POSIX.
---
 newlib/ChangeLog          |  6 ++++++
 newlib/libc/posix/popen.c | 13 +++++++++++--
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/newlib/ChangeLog b/newlib/ChangeLog
index 9e068c8a3f..231d02d9cc 100644
--- a/newlib/ChangeLog
+++ b/newlib/ChangeLog
@@ -1,3 +1,9 @@
+2006-08-22  Eric Blake  <ebb9@byu.net>
+
+	* libc/posix/popen.c (popen): Don't close output end of pipe in
+	child if stdout was closed on entry.
+	[HAVE_FCNTL]: In parent, mark file as close-on-exec, per POSIX.
+
 2006-08-19  Ramana Radhakrishnan  <ramana.r@gmail.com>
 
 	* sys/types.h: Correct syntax error caused by missing '\' on #ifdef
diff --git a/newlib/libc/posix/popen.c b/newlib/libc/posix/popen.c
index 0f25a3ed05..2d3777133f 100644
--- a/newlib/libc/posix/popen.c
+++ b/newlib/libc/posix/popen.c
@@ -1,7 +1,7 @@
 /*	$NetBSD: popen.c,v 1.11 1995/06/16 07:05:33 jtc Exp $	*/
 
 /*
- * Copyright (c) 1988, 1993
+ * Copyright (c) 1988, 1993, 2006
  *	The Regents of the University of California.  All rights reserved.
  *
  * This code is derived from software written by Ken Arnold and
@@ -55,6 +55,7 @@ static char rcsid[] = "$NetBSD: popen.c,v 1.11 1995/06/16 07:05:33 jtc Exp $";
 #include <stdlib.h>
 #include <string.h>
 #include <paths.h>
+#include <fcntl.h>
 
 static struct pid {
 	struct pid *next;
@@ -102,7 +103,9 @@ _DEFUN(popen, (program, type),
 				(void)dup2(pdes[1], STDOUT_FILENO);
 				(void)close(pdes[1]);
 			}
-			(void) close(pdes[0]);
+			if (pdes[0] != STDOUT_FILENO) {
+				(void) close(pdes[0]);
+			}
 		} else {
 			if (pdes[0] != STDIN_FILENO) {
 				(void)dup2(pdes[0], STDIN_FILENO);
@@ -129,6 +132,12 @@ _DEFUN(popen, (program, type),
 		(void)close(pdes[0]);
 	}
 
+#ifdef HAVE_FCNTL
+	/* Hide pipe from future popens; assume fcntl can't fail.  */
+	fcntl (fileno (iop), F_SETFD,
+	       fcntl (fileno (iop), F_GETFD, 0) | FD_CLOEXEC);
+#endif /* HAVE_FCNTL */
+
 	/* Link into list of file descriptors. */
 	cur->fp = iop;
 	cur->pid =  pid;
-- 
2.11.0