unistd: guarantee STDIN_FILENO here, for OS/2 EMX * lib/unistd.in.h (STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO): Guarantee a definition. * doc/posix-headers/unistd.texi (unistd.h): Document the bug. * modules/unistd-safer (Depends-on): Add dependency on unistd. * lib/c-stack.c (STDERR_FILENO): Rely on <unistd.h>. * lib/dup-safer.c (STDERR_FILENO): Likewise. * lib/execute.c (STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO): Likewise. * lib/fd-safer.c (STDIN_FILENO, STDERR_FILENO): Likewise. * lib/fopen-safer.c (STDERR_FILENO): Likewise. * lib/pipe.c (STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO): Likewise. * lib/tmpfile-safer.c (STDERR_FILENO): Likewise. * tests/test-posix_spawn1.c (STDIN_FILENO, STDOUT_FILENO) (STDERR_FILENO): Likewise. * tests/test-posix_spawn2.c (STDIN_FILENO, STDOUT_FILENO) (STDERR_FILENO): Likewise. * tests/test-posix_spawn3.c (STDIN_FILENO, STDOUT_FILENO) (STDERR_FILENO): Likewise. Reported by Elbert Pol. Signed-off-by: Eric Blake <ebb9@byu.net>

--- a/lib/c-stack.c
+++ b/lib/c-stack.c
@@ -1,6 +1,7 @@
 /* Stack overflow handling.
 
-   Copyright (C) 2002, 2004, 2006, 2008 Free Software Foundation, Inc.
+   Copyright (C) 2002, 2004, 2006, 2008, 2009 Free Software
+   Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -67,9 +68,6 @@
 #endif
 
 #include <unistd.h>
-#ifndef STDERR_FILENO
-# define STDERR_FILENO 2
-#endif
 
 #if HAVE_LIBSIGSEGV
 # include <sigsegv.h>