diff --git a/check.t b/check.t
index e8c3bf6..e920866 100644
--- a/check.t
+++ b/check.t
@@ -1,4 +1,4 @@
-# $MirOS: src/bin/mksh/check.t,v 1.221 2008/09/14 20:24:57 tg Exp $
+# $MirOS: src/bin/mksh/check.t,v 1.222 2008/09/17 19:31:28 tg Exp $
 # $OpenBSD: bksl-nl.t,v 1.2 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: history.t,v 1.5 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: read.t,v 1.3 2003/03/10 03:48:16 david Exp $
@@ -7,7 +7,7 @@
 # http://www.research.att.com/~gsf/public/ifs.sh
 
 expected-stdout:
-	@(#)MIRBSD KSH R35 2008/09/14
+	@(#)MIRBSD KSH R35 2008/09/17
 description:
 	Check version of shell.
 stdin:
@@ -4251,6 +4251,25 @@ expected-stdout:
 	posix
 	brex
 ---
+name: posix-mode-2
+description:
+	Check that posix mode is automatically turned on
+category: !smksh
+stdin:
+	ln -s "$__progname" ksh
+	ln -s "$__progname" sh
+	ln -s "$__progname" -ksh
+	ln -s "$__progname" -sh
+	for shell in {,-}{,k}sh; do
+		print -- $shell $(./$shell +l -c \
+		    '[[ $(set +o) == *@(-o posix)@(| *) ]] && echo posix || echo noposix')
+	done
+expected-stdout:
+	sh posix
+	ksh noposix
+	-sh posix
+	-ksh noposix
+---
 name: pipeline-1
 description:
 	pdksh bug: last command of a pipeline is executed in a
@@ -5307,3 +5326,28 @@ stdin:
 		exit 1
 	fi
 ---
+name: fd-cloexec-1
+description:
+	Verify that file descriptors > 2 are private for Korn shells
+file-setup: file 644 "test.sh"
+	print -u3 Fowl
+stdin:
+	exec 3>&1
+	"$__progname" test.sh
+expected-exit: e != 0
+expected-stderr:
+	test.sh[1]: print: -u: 3: bad file descriptor
+---
+name: fd-cloexec-2
+description:
+	Verify that file descriptors > 2 are not private for POSIX shells
+	See Debian Bug #154540, Closes: #499139
+file-setup: file 644 "test.sh"
+	print -u3 Fowl
+stdin:
+	set -o posix
+	exec 3>&1
+	"$__progname" test.sh
+expected-stdout:
+	Fowl
+---
diff --git a/funcs.c b/funcs.c
index 71650ec..cb64211 100644
--- a/funcs.c
+++ b/funcs.c
@@ -5,7 +5,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/funcs.c,v 1.86 2008/08/02 17:45:11 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/funcs.c,v 1.87 2008/09/17 19:31:29 tg Exp $");
 
 /* A leading = means assignments before command are kept;
  * a leading * means a POSIX special builtin;
@@ -2308,8 +2308,8 @@ c_exec(const char **wp __unused)
 		for (i = 0; i < NUFILE; i++) {
 			if (e->savefd[i] > 0)
 				close(e->savefd[i]);
-			/* For ksh keep anything > 2 private */
-			if (i > 2 && e->savefd[i])
+			/* For ksh (but not sh), keep anything > 2 private */
+			if (!Flag(FPOSIX) && i > 2 && e->savefd[i])
 				fcntl(i, F_SETFD, FD_CLOEXEC);
 		}
 		e->savefd = NULL;
diff --git a/main.c b/main.c
index 37e76ee..d2d82f0 100644
--- a/main.c
+++ b/main.c
@@ -13,7 +13,7 @@
 #include <locale.h>
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/main.c,v 1.101 2008/07/10 18:34:08 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/main.c,v 1.102 2008/09/17 19:31:29 tg Exp $");
 
 extern char **environ;
 
@@ -173,6 +173,21 @@ main(int argc, const char *argv[])
 	Flag(FVITABCOMPLETE) = 1;
 #endif
 
+#ifndef MKSH_SMALL
+	/* Set FPOSIX if we're called as -sh or /bin/sh or so */
+	{
+		const char *cc;
+
+		cc = kshname;
+		i = 0; argi = 0;
+		while (cc[i] != '\0')
+			if ((cc[i++] | 2) == '/')
+				argi = i;
+		if (((cc[argi] | 0x20) == 's') && ((cc[argi + 1] | 0x20) == 'h'))
+			change_flag(FPOSIX, OF_FIRSTTIME, 1);
+	}
+#endif
+
 	/* import environment */
 	if (environ != NULL)
 		for (wp = (const char **)environ; *wp != NULL; wp++)
diff --git a/mksh.1 b/mksh.1
index 60f6e3b..7a996d1 100644
--- a/mksh.1
+++ b/mksh.1
@@ -1,4 +1,4 @@
-.\" $MirOS: src/bin/mksh/mksh.1,v 1.135 2008/09/17 19:27:16 tg Exp $
+.\" $MirOS: src/bin/mksh/mksh.1,v 1.136 2008/09/17 19:31:30 tg Exp $
 .\" $OpenBSD: ksh.1,v 1.122 2008/05/17 23:31:52 sobrado Exp $
 .\"-
 .\" Try to make GNU groff and AT&T nroff more compatible
@@ -2080,6 +2080,11 @@ pipelines are created and in the order they are given, so the following
 will print an error with a line number prepended to it:
 .Pp
 .D1 $ cat /foo/bar 2\*(Gt&1 \*(Gt /dev/null \*(Ba cat \-n
+.Pp
+File descriptors created by input/output redirections are private to the
+Korn shell, but passed to sub-processes if
+.Fl o Ic posix
+is set.
 .Ss Arithmetic expressions
 Integer arithmetic expressions can be used with the
 .Ic let
@@ -3580,9 +3585,11 @@ and
 commands above for more details.
 .It Ic posix
 Enable POSIX mode.
-Currently, this just turns off
+Automatically enabled if the basename of the shell invocation begins with
+.Dq sh .
+As a side effect, setting this flag turns off
 .Ic braceexpand
-mode when turned on, which can be turned back on manually.
+mode, which can be turned back on manually.
 .It Ic restricted
 The shell is a restricted shell.
 This option can only be used when the shell is invoked.
@@ -5525,7 +5532,7 @@ and many other persons, and is currently maintained by
 .An Thorsten Glaser Aq tg@mirbsd.de .
 .Sh BUGS
 This document attempts to describe
-.Nm mksh\ R35
+.Nm mksh\ R35c
 and up,
 compiled without any options impacting functionality, such as
 .Dv MKSH_SMALL ,
diff --git a/sh.h b/sh.h
index 8788a3c..496a8b5 100644
--- a/sh.h
+++ b/sh.h
@@ -100,9 +100,9 @@
 #define __SCCSID(x)	__IDSTRING(sccsid,x)
 
 #ifdef EXTERN
-__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.231 2008/09/14 20:24:59 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.232 2008/09/17 19:31:30 tg Exp $");
 #endif
-#define MKSH_VERSION "R35 2008/09/14"
+#define MKSH_VERSION "R35 2008/09/17"
 
 #ifndef MKSH_INCLUDES_ONLY