Merge from gnulib.

11 files changed, 202 insertions, 144 deletions

diff --git a/ChangeLog b/ChangeLog
index c510360e30f..93c3c333725 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2013-02-08  Paul Eggert  <eggert@cs.ucla.edu>
+
+	Merge from gnulib, incorporating:
+	2013-02-08 careadlinkat: stop exporting careadlinkatcwd
+	The MS-Windows port can remove careadlinkatcwd at its convenience.
+	2013-02-08 extensions: port better to HP-UX
+	2013-02-06 extensions: port better to MINIX 3, HP-UX, autoheader 2.62
+	2013-02-06 unistd: avoid namespace pollution on non-glibc systems
+	2013-02-04 secure_getenv: new module [module not used by Emacs]
+	2013-01-30 sys_time: port to Solaris 2.6
+
 2013-02-01  Paul Eggert  <eggert@cs.ucla.edu>
 
 	Use fdopendir, fstatat and readlinkat, for efficiency (Bug#13539).
diff --git a/doc/misc/texinfo.tex b/doc/misc/texinfo.tex
index d64f45bbee9..85f184cc4cb 100644
--- a/doc/misc/texinfo.tex
+++ b/doc/misc/texinfo.tex
@@ -3,7 +3,7 @@
 % Load plain if necessary, i.e., if running under initex.
 \expandafter\ifx\csname fmtname\endcsname\relax\input plain\fi
 %
-\def\texinfoversion{2013-01-01.15}
+\def\texinfoversion{2013-02-01.11}
 %
 % Copyright 1985, 1986, 1988, 1990, 1991, 1992, 1993, 1994, 1995,
 % 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
@@ -2496,7 +2496,7 @@ end
      \let-\codedash
      \let_\codeunder
     \else
-     \let-\realdash
+     \let-\normaldash
      \let_\realunder
     \fi
     \codex
@@ -2505,7 +2505,7 @@ end
 
 \def\codex #1{\tclose{#1}\endgroup}
 
-\def\realdash{-}
+\def\normaldash{-}
 \def\codedash{-\discretionary{}{}{}}
 \def\codeunder{%
   % this is all so @math{@code{var_name}+1} can work.  In math mode, _
@@ -2520,9 +2520,9 @@ end
 }
 
 % An additional complication: the above will allow breaks after, e.g.,
-% each of the four underscores in __typeof__.  This is undesirable in
-% some manuals, especially if they don't have long identifiers in
-% general.  @allowcodebreaks provides a way to control this.
+% each of the four underscores in __typeof__.  This is bad.
+% @allowcodebreaks provides a document-level way to turn breaking at -
+% and _ on and off.
 %
 \newif\ifallowcodebreaks  \allowcodebreakstrue
 
@@ -4188,7 +4188,7 @@ end
     % ..., but we might end up with active ones in the argument if
     % we're called from @code, as @code{@value{foo-bar_}}, though.
     % So \let them to their normal equivalents.
-    \let-\realdash \let_\normalunderscore
+    \let-\normaldash \let_\normalunderscore
   }
 }
 
@@ -9993,22 +9993,26 @@ directory should work if nowhere else does.}
 @gdef@otherbackslash{@let\=@realbackslash}
 
 % Same as @turnoffactive except outputs \ as {\tt\char`\\} instead of
-% the literal character `\'.
-%
-@def@normalturnoffactive{%
-  @let"=@normaldoublequote
-  @let$=@normaldollar %$ font-lock fix
-  @let+=@normalplus
-  @let<=@normalless
-  @let>=@normalgreater
-  @let\=@normalbackslash
-  @let^=@normalcaret
-  @let_=@normalunderscore
-  @let|=@normalverticalbar
-  @let~=@normaltilde
-  @markupsetuplqdefault
-  @markupsetuprqdefault
-  @unsepspaces
+% the literal character `\'.  Also revert - to its normal character, in
+% case the active - from code has slipped in.
+%
+{@catcode`- = @active
+ @gdef@normalturnoffactive{%
+   @let-=@normaldash
+   @let"=@normaldoublequote
+   @let$=@normaldollar %$ font-lock fix
+   @let+=@normalplus
+   @let<=@normalless
+   @let>=@normalgreater
+   @let\=@normalbackslash
+   @let^=@normalcaret
+   @let_=@normalunderscore
+   @let|=@normalverticalbar
+   @let~=@normaltilde
+   @markupsetuplqdefault
+   @markupsetuprqdefault
+   @unsepspaces
+ }
 }
 
 % Make _ and + \other characters, temporarily.
diff --git a/lib/careadlinkat.c b/lib/careadlinkat.c
index d242ffaac7d..e2c19d1c1f1 100644
--- a/lib/careadlinkat.c
+++ b/lib/careadlinkat.c
@@ -25,6 +25,7 @@
 #include <errno.h>
 #include <limits.h>
 #include <string.h>
+#include <unistd.h>
 
 /* Define this independently so that stdint.h is not a prerequisite.  */
 #ifndef SIZE_MAX
diff --git a/lib/careadlinkat.h b/lib/careadlinkat.h
index 965573bef3a..46f88ae288a 100644
--- a/lib/careadlinkat.h
+++ b/lib/careadlinkat.h
@@ -52,15 +52,12 @@ char *careadlinkat (int fd, char const *filename,
                     ssize_t (*preadlinkat) (int, char const *,
                                             char *, size_t));
 
-/* Suitable value for careadlinkat's FD argument,
-   when doing a plain readlink:
-   Pass FD = AT_FDCWD.  */
+/* Suitable value for careadlinkat's FD argument.  */
 #if HAVE_READLINKAT
 /* AT_FDCWD is declared in <fcntl.h>.  */
 #else
 /* Define AT_FDCWD independently, so that the careadlinkat module does
-   not depend on the fcntl-h module.  The value does not matter, since
-   careadlinkatcwd ignores it, but we might as well use the same value
+   not depend on the fcntl-h module.  We might as well use the same value
    as fcntl-h.  */
 # ifndef AT_FDCWD
 #  define AT_FDCWD (-3041965)
diff --git a/lib/gnulib.mk b/lib/gnulib.mk
index 89317fd2088..8103eec88a0 100644
--- a/lib/gnulib.mk
+++ b/lib/gnulib.mk
@@ -1032,6 +1032,7 @@ stdlib.h: stdlib.in.h $(top_builddir)/config.status $(CXXDEFS_H) \
 	      -e 's/@''GNULIB_REALLOC_POSIX''@/$(GNULIB_REALLOC_POSIX)/g' \
 	      -e 's/@''GNULIB_REALPATH''@/$(GNULIB_REALPATH)/g' \
 	      -e 's/@''GNULIB_RPMATCH''@/$(GNULIB_RPMATCH)/g' \
+	      -e 's/@''GNULIB_SECURE_GETENV''@/$(GNULIB_SECURE_GETENV)/g' \
 	      -e 's/@''GNULIB_SETENV''@/$(GNULIB_SETENV)/g' \
 	      -e 's/@''GNULIB_STRTOD''@/$(GNULIB_STRTOD)/g' \
 	      -e 's/@''GNULIB_STRTOLL''@/$(GNULIB_STRTOLL)/g' \
@@ -1060,6 +1061,7 @@ stdlib.h: stdlib.in.h $(top_builddir)/config.status $(CXXDEFS_H) \
 	      -e 's|@''HAVE_RANDOM_R''@|$(HAVE_RANDOM_R)|g' \
 	      -e 's|@''HAVE_REALPATH''@|$(HAVE_REALPATH)|g' \
 	      -e 's|@''HAVE_RPMATCH''@|$(HAVE_RPMATCH)|g' \
+	      -e 's|@''HAVE_SECURE_GETENV''@|$(HAVE_SECURE_GETENV)|g' \
 	      -e 's|@''HAVE_DECL_SETENV''@|$(HAVE_DECL_SETENV)|g' \
 	      -e 's|@''HAVE_STRTOD''@|$(HAVE_STRTOD)|g' \
 	      -e 's|@''HAVE_STRTOLL''@|$(HAVE_STRTOLL)|g' \
diff --git a/lib/stdlib.in.h b/lib/stdlib.in.h
index 422ad714c32..e054c520ebe 100644
--- a/lib/stdlib.in.h
+++ b/lib/stdlib.in.h
@@ -767,6 +767,22 @@ _GL_WARN_ON_USE (rpmatch, "rpmatch is unportable - "
 # endif
 #endif
 
+#if @GNULIB_SECURE_GETENV@
+/* Look up NAME in the environment, returning 0 in insecure situations.  */
+# if !@HAVE_SECURE_GETENV@
+_GL_FUNCDECL_SYS (secure_getenv, char *,
+                  (char const *name) _GL_ARG_NONNULL ((1)));
+# endif
+_GL_CXXALIAS_SYS (secure_getenv, int, (char const *name));
+_GL_CXXALIASWARN (secure_getenv);
+#elif defined GNULIB_POSIXCHECK
+# undef secure_getenv
+# if HAVE_RAW_DECL_SECURE_GETENV
+_GL_WARN_ON_USE (secure_getenv, "secure_getenv is unportable - "
+                 "use gnulib module secure_getenv for portability");
+# endif
+#endif
+
 #if @GNULIB_SETENV@
 /* Set NAME to VALUE in the environment.
    If REPLACE is nonzero, overwrite an existing value.  */
diff --git a/lib/sys_select.in.h b/lib/sys_select.in.h
index edff088a125..521ccef321d 100644
--- a/lib/sys_select.in.h
+++ b/lib/sys_select.in.h
@@ -19,14 +19,25 @@
 # endif
 @PRAGMA_COLUMNS@
 
-/* On OSF/1, <sys/types.h> and <sys/time.h> include <sys/select.h>.
+/* On OSF/1 and Solaris 2.6, <sys/types.h> and <sys/time.h>
+   both include <sys/select.h>.
    Simply delegate to the system's header in this case.  */
-#if @HAVE_SYS_SELECT_H@ && defined __osf__ && (defined _SYS_TYPES_H_ && !defined _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TYPES_H) && defined _OSF_SOURCE
+#if (@HAVE_SYS_SELECT_H@                                                \
+     && ((defined __osf__ && defined _SYS_TYPES_H_ && defined _OSF_SOURCE) \
+         || (defined __sun && defined _SYS_TYPES_H                      \
+             && (! (defined _XOPEN_SOURCE || defined _POSIX_C_SOURCE)   \
+                 || defined __EXTENSIONS__)))                           \
+     && !defined _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TYPES_H)
 
 # define _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TYPES_H
 # @INCLUDE_NEXT@ @NEXT_SYS_SELECT_H@
 
-#elif @HAVE_SYS_SELECT_H@ && defined __osf__ && (defined _SYS_TIME_H_ && !defined _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TIME_H) && defined _OSF_SOURCE
+#elif (@HAVE_SYS_SELECT_H@                                              \
+       && ((defined __osf__ && defined _SYS_TIME_H_ && defined _OSF_SOURCE) \
+           || (defined __sun && defined _SYS_TIME_H                     \
+               && (! (defined _XOPEN_SOURCE || defined _POSIX_C_SOURCE) \
+                   || defined __EXTENSIONS__)))                         \
+       && !defined _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TIME_H)
 
 # define _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TIME_H
 # @INCLUDE_NEXT@ @NEXT_SYS_SELECT_H@
diff --git a/lib/sys_time.in.h b/lib/sys_time.in.h
index 1b7736bee02..656c3f13ad2 100644
--- a/lib/sys_time.in.h
+++ b/lib/sys_time.in.h
@@ -17,37 +17,34 @@
 
 /* Written by Paul Eggert.  */
 
+#ifndef _@GUARD_PREFIX@_SYS_TIME_H
+
 #if __GNUC__ >= 3
 @PRAGMA_SYSTEM_HEADER@
 #endif
 @PRAGMA_COLUMNS@
 
-#if defined _@GUARD_PREFIX@_SYS_TIME_H
-
-/* Simply delegate to the system's header, without adding anything.  */
-# if @HAVE_SYS_TIME_H@
-#  @INCLUDE_NEXT@ @NEXT_SYS_TIME_H@
-# endif
-
-#else
+/* The include_next requires a split double-inclusion guard.  */
+#if @HAVE_SYS_TIME_H@
+# @INCLUDE_NEXT@ @NEXT_SYS_TIME_H@
+#endif
 
-# define _@GUARD_PREFIX@_SYS_TIME_H
+#ifndef _@GUARD_PREFIX@_SYS_TIME_H
+#define _@GUARD_PREFIX@_SYS_TIME_H
 
-# if @HAVE_SYS_TIME_H@
-#  @INCLUDE_NEXT@ @NEXT_SYS_TIME_H@
-# else
-#  include <time.h>
-# endif
+#if ! @HAVE_SYS_TIME_H@
+# include <time.h>
+#endif
 
 /* On native Windows with MSVC, get the 'struct timeval' type.
    Also, on native Windows with a 64-bit time_t, where we are overriding the
    'struct timeval' type, get all declarations of system functions whose
    signature contains 'struct timeval'.  */
-# if (defined _MSC_VER || @REPLACE_STRUCT_TIMEVAL@) && @HAVE_WINSOCK2_H@ && !defined _GL_INCLUDING_WINSOCK2_H
-#  define _GL_INCLUDING_WINSOCK2_H
-#  include <winsock2.h>
-#  undef _GL_INCLUDING_WINSOCK2_H
-# endif
+#if (defined _MSC_VER || @REPLACE_STRUCT_TIMEVAL@) && @HAVE_WINSOCK2_H@ && !defined _GL_INCLUDING_WINSOCK2_H
+# define _GL_INCLUDING_WINSOCK2_H
+# include <winsock2.h>
+# undef _GL_INCLUDING_WINSOCK2_H
+#endif
 
 /* The definitions of _GL_FUNCDECL_RPL etc. are copied here.  */
 
@@ -55,112 +52,112 @@
 
 /* The definition of _GL_WARN_ON_USE is copied here.  */
 
-# ifdef __cplusplus
+#ifdef __cplusplus
 extern "C" {
-# endif
+#endif
 
-# if !@HAVE_STRUCT_TIMEVAL@ || @REPLACE_STRUCT_TIMEVAL@
+#if !@HAVE_STRUCT_TIMEVAL@ || @REPLACE_STRUCT_TIMEVAL@
 
-#  if @REPLACE_STRUCT_TIMEVAL@
-#   define timeval rpl_timeval
-#  endif
+# if @REPLACE_STRUCT_TIMEVAL@
+#  define timeval rpl_timeval
+# endif
 
-#  if !GNULIB_defined_struct_timeval
+# if !GNULIB_defined_struct_timeval
 struct timeval
 {
   time_t tv_sec;
   long int tv_usec;
 };
-#   define GNULIB_defined_struct_timeval 1
-#  endif
-
+#  define GNULIB_defined_struct_timeval 1
 # endif
 
-# ifdef __cplusplus
+#endif
+
+#ifdef __cplusplus
 }
-# endif
+#endif
 
-# if @GNULIB_GETTIMEOFDAY@
-#  if @REPLACE_GETTIMEOFDAY@
-#   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
-#    undef gettimeofday
-#    define gettimeofday rpl_gettimeofday
-#   endif
+#if @GNULIB_GETTIMEOFDAY@
+# if @REPLACE_GETTIMEOFDAY@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef gettimeofday
+#   define gettimeofday rpl_gettimeofday
+#  endif
 _GL_FUNCDECL_RPL (gettimeofday, int,
                   (struct timeval *restrict, void *restrict)
                   _GL_ARG_NONNULL ((1)));
 _GL_CXXALIAS_RPL (gettimeofday, int,
                   (struct timeval *restrict, void *restrict));
-#  else
-#   if !@HAVE_GETTIMEOFDAY@
+# else
+#  if !@HAVE_GETTIMEOFDAY@
 _GL_FUNCDECL_SYS (gettimeofday, int,
                   (struct timeval *restrict, void *restrict)
                   _GL_ARG_NONNULL ((1)));
-#   endif
+#  endif
 /* Need to cast, because on glibc systems, by default, the second argument is
                                                   struct timezone *.  */
 _GL_CXXALIAS_SYS_CAST (gettimeofday, int,
                        (struct timeval *restrict, void *restrict));
-#  endif
+# endif
 _GL_CXXALIASWARN (gettimeofday);
-# elif defined GNULIB_POSIXCHECK
-#  undef gettimeofday
-#  if HAVE_RAW_DECL_GETTIMEOFDAY
+#elif defined GNULIB_POSIXCHECK
+# undef gettimeofday
+# if HAVE_RAW_DECL_GETTIMEOFDAY
 _GL_WARN_ON_USE (gettimeofday, "gettimeofday is unportable - "
                  "use gnulib module gettimeofday for portability");
-#  endif
 # endif
+#endif
 
 /* Hide some function declarations from <winsock2.h>.  */
 
-# if defined _MSC_VER && @HAVE_WINSOCK2_H@
-#  if !defined _@GUARD_PREFIX@_UNISTD_H
-#   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
-#    undef close
-#    define close close_used_without_including_unistd_h
-#   else
+#if defined _MSC_VER && @HAVE_WINSOCK2_H@
+# if !defined _@GUARD_PREFIX@_UNISTD_H
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef close
+#   define close close_used_without_including_unistd_h
+#  else
      _GL_WARN_ON_USE (close,
                       "close() used without including <unistd.h>");
-#   endif
-#   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
-#    undef gethostname
-#    define gethostname gethostname_used_without_including_unistd_h
-#   else
+#  endif
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef gethostname
+#   define gethostname gethostname_used_without_including_unistd_h
+#  else
      _GL_WARN_ON_USE (gethostname,
                       "gethostname() used without including <unistd.h>");
-#   endif
 #  endif
-#  if !defined _@GUARD_PREFIX@_SYS_SOCKET_H
-#   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
-#    undef socket
-#    define socket              socket_used_without_including_sys_socket_h
-#    undef connect
-#    define connect             connect_used_without_including_sys_socket_h
-#    undef accept
-#    define accept              accept_used_without_including_sys_socket_h
-#    undef bind
-#    define bind                bind_used_without_including_sys_socket_h
-#    undef getpeername
-#    define getpeername         getpeername_used_without_including_sys_socket_h
-#    undef getsockname
-#    define getsockname         getsockname_used_without_including_sys_socket_h
-#    undef getsockopt
-#    define getsockopt          getsockopt_used_without_including_sys_socket_h
-#    undef listen
-#    define listen              listen_used_without_including_sys_socket_h
-#    undef recv
-#    define recv                recv_used_without_including_sys_socket_h
-#    undef send
-#    define send                send_used_without_including_sys_socket_h
-#    undef recvfrom
-#    define recvfrom            recvfrom_used_without_including_sys_socket_h
-#    undef sendto
-#    define sendto              sendto_used_without_including_sys_socket_h
-#    undef setsockopt
-#    define setsockopt          setsockopt_used_without_including_sys_socket_h
-#    undef shutdown
-#    define shutdown            shutdown_used_without_including_sys_socket_h
-#   else
+# endif
+# if !defined _@GUARD_PREFIX@_SYS_SOCKET_H
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef socket
+#   define socket              socket_used_without_including_sys_socket_h
+#   undef connect
+#   define connect             connect_used_without_including_sys_socket_h
+#   undef accept
+#   define accept              accept_used_without_including_sys_socket_h
+#   undef bind
+#   define bind                bind_used_without_including_sys_socket_h
+#   undef getpeername
+#   define getpeername         getpeername_used_without_including_sys_socket_h
+#   undef getsockname
+#   define getsockname         getsockname_used_without_including_sys_socket_h
+#   undef getsockopt
+#   define getsockopt          getsockopt_used_without_including_sys_socket_h
+#   undef listen
+#   define listen              listen_used_without_including_sys_socket_h
+#   undef recv
+#   define recv                recv_used_without_including_sys_socket_h
+#   undef send
+#   define send                send_used_without_including_sys_socket_h
+#   undef recvfrom
+#   define recvfrom            recvfrom_used_without_including_sys_socket_h
+#   undef sendto
+#   define sendto              sendto_used_without_including_sys_socket_h
+#   undef setsockopt
+#   define setsockopt          setsockopt_used_without_including_sys_socket_h
+#   undef shutdown
+#   define shutdown            shutdown_used_without_including_sys_socket_h
+#  else
      _GL_WARN_ON_USE (socket,
                       "socket() used without including <sys/socket.h>");
      _GL_WARN_ON_USE (connect,
@@ -189,17 +186,18 @@ _GL_WARN_ON_USE (gettimeofday, "gettimeofday is unportable - "
                       "setsockopt() used without including <sys/socket.h>");
      _GL_WARN_ON_USE (shutdown,
                       "shutdown() used without including <sys/socket.h>");
-#   endif
 #  endif
-#  if !defined _@GUARD_PREFIX@_SYS_SELECT_H
-#   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
-#    undef select
-#    define select select_used_without_including_sys_select_h
-#   else
+# endif
+# if !defined _@GUARD_PREFIX@_SYS_SELECT_H
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef select
+#   define select select_used_without_including_sys_select_h
+#  else
      _GL_WARN_ON_USE (select,
                       "select() used without including <sys/select.h>");
-#   endif
 #  endif
 # endif
+#endif
 
 #endif /* _@GUARD_PREFIX@_SYS_TIME_H */
+#endif /* _@GUARD_PREFIX@_SYS_TIME_H */
diff --git a/lib/unistd.in.h b/lib/unistd.in.h
index a870fe7b4a3..675c7e6a552 100644
--- a/lib/unistd.in.h
+++ b/lib/unistd.in.h
@@ -110,6 +110,7 @@
 /* Get getopt(), optarg, optind, opterr, optopt.
    But avoid namespace pollution on glibc systems.  */
 #if @GNULIB_UNISTD_H_GETOPT@ && !defined __GLIBC__ && !defined _GL_SYSTEM_GETOPT
+# define __need_getopt
 # include <getopt.h>
 #endif
 
diff --git a/m4/extensions.m4 b/m4/extensions.m4
index 617323b244c..07ba376c0e7 100644
--- a/m4/extensions.m4
+++ b/m4/extensions.m4
@@ -1,4 +1,4 @@
-# serial 12  -*- Autoconf -*-
+# serial 13  -*- Autoconf -*-
 # Enable extensions on systems that normally disable them.
 
 # Copyright (C) 2003, 2006-2013 Free Software Foundation, Inc.
@@ -8,7 +8,7 @@
 
 # This definition of AC_USE_SYSTEM_EXTENSIONS is stolen from CVS
 # Autoconf.  Perhaps we can remove this once we can assume Autoconf
-# 2.62 or later everywhere, but since CVS Autoconf mutates rapidly
+# 2.70 or later everywhere, but since Autoconf mutates rapidly
 # enough in this area it's likely we'll need to redefine
 # AC_USE_SYSTEM_EXTENSIONS for quite some time.
 
@@ -30,6 +30,7 @@
 # ------------------------
 # Enable extensions on systems that normally disable them,
 # typically due to standards-conformance issues.
+#
 # Remember that #undef in AH_VERBATIM gets replaced with #define by
 # AC_DEFINE.  The goal here is to define all known feature-enabling
 # macros, then, if reports of conflicts are made, disable macros that
@@ -38,8 +39,6 @@ AC_DEFUN_ONCE([AC_USE_SYSTEM_EXTENSIONS],
 [AC_BEFORE([$0], [AC_COMPILE_IFELSE])dnl
 AC_BEFORE([$0], [AC_RUN_IFELSE])dnl
 
-  AC_REQUIRE([AC_CANONICAL_HOST])
-
   AC_CHECK_HEADER([minix/config.h], [MINIX=yes], [MINIX=])
   if test "$MINIX" = yes; then
     AC_DEFINE([_POSIX_SOURCE], [1],
@@ -50,24 +49,18 @@ AC_BEFORE([$0], [AC_RUN_IFELSE])dnl
        except with this defined.])
     AC_DEFINE([_MINIX], [1],
       [Define to 1 if on MINIX.])
+    AC_DEFINE([_NETBSD_SOURCE], [1],
+      [Define to 1 to make NetBSD features available.  MINIX 3 needs this.])
   fi
 
-  dnl HP-UX 11.11 defines mbstate_t only if _XOPEN_SOURCE is defined to 500,
-  dnl regardless of whether the flags -Ae or _D_HPUX_SOURCE=1 are already
-  dnl provided.
-  case "$host_os" in
-    hpux*)
-      AC_DEFINE([_XOPEN_SOURCE], [500],
-        [Define to 500 only on HP-UX.])
-      ;;
-  esac
-
-  AH_VERBATIM([__EXTENSIONS__],
+dnl Use a different key than __EXTENSIONS__, as that name broke existing
+dnl configure.ac when using autoheader 2.62.
+  AH_VERBATIM([USE_SYSTEM_EXTENSIONS],
 [/* Enable extensions on AIX 3, Interix.  */
 #ifndef _ALL_SOURCE
 # undef _ALL_SOURCE
 #endif
-/* Enable general extensions on Mac OS X.  */
+/* Enable general extensions on OS X.  */
 #ifndef _DARWIN_C_SOURCE
 # undef _DARWIN_C_SOURCE
 #endif
@@ -83,6 +76,12 @@ AC_BEFORE([$0], [AC_RUN_IFELSE])dnl
 #ifndef _TANDEM_SOURCE
 # undef _TANDEM_SOURCE
 #endif
+/* Enable X/Open extensions if necessary.  HP-UX 11.11 defines
+   mbstate_t only if _XOPEN_SOURCE is defined to 500, regardless of
+   whether compiling with -Ae or -D_HPUX_SOURCE=1.  */
+#ifndef _XOPEN_SOURCE
+# undef _XOPEN_SOURCE
+#endif
 /* Enable general extensions on Solaris.  */
 #ifndef __EXTENSIONS__
 # undef __EXTENSIONS__
@@ -103,6 +102,22 @@ AC_BEFORE([$0], [AC_RUN_IFELSE])dnl
   AC_DEFINE([_GNU_SOURCE])
   AC_DEFINE([_POSIX_PTHREAD_SEMANTICS])
   AC_DEFINE([_TANDEM_SOURCE])
+  AC_CACHE_CHECK([whether _XOPEN_SOURCE should be defined],
+    [ac_cv_should_define__xopen_source],
+    [ac_cv_should_define__xopen_source=no
+     AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM([[
+          #include <wchar.h>
+          mbstate_t x;]])],
+       [],
+       [AC_COMPILE_IFELSE(
+          [AC_LANG_PROGRAM([[
+             #define _XOPEN_SOURCE 500
+             #include <wchar.h>
+             mbstate_t x;]])],
+          [ac_cv_should_define__xopen_source=yes])])])
+  test $ac_cv_should_define__xopen_source = yes &&
+    AC_DEFINE([_XOPEN_SOURCE], [500])
 ])# AC_USE_SYSTEM_EXTENSIONS
 
 # gl_USE_SYSTEM_EXTENSIONS
diff --git a/m4/stdlib_h.m4 b/m4/stdlib_h.m4
index 79103bc7eb5..2027ab3c1d0 100644
--- a/m4/stdlib_h.m4
+++ b/m4/stdlib_h.m4
@@ -1,4 +1,4 @@
-# stdlib_h.m4 serial 41
+# stdlib_h.m4 serial 42
 dnl Copyright (C) 2007-2013 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -22,7 +22,7 @@ AC_DEFUN([gl_STDLIB_H],
     ]], [_Exit atoll canonicalize_file_name getloadavg getsubopt grantpt
     initstate initstate_r mkdtemp mkostemp mkostemps mkstemp mkstemps
     posix_openpt ptsname ptsname_r random random_r realpath rpmatch
-    setenv setstate setstate_r srandom srandom_r
+    secure_getenv setenv setstate setstate_r srandom srandom_r
     strtod strtoll strtoull unlockpt unsetenv])
 ])
 
@@ -60,6 +60,7 @@ AC_DEFUN([gl_STDLIB_H_DEFAULTS],
   GNULIB_REALLOC_POSIX=0; AC_SUBST([GNULIB_REALLOC_POSIX])
   GNULIB_REALPATH=0;      AC_SUBST([GNULIB_REALPATH])
   GNULIB_RPMATCH=0;       AC_SUBST([GNULIB_RPMATCH])
+  GNULIB_SECURE_GETENV=0; AC_SUBST([GNULIB_SECURE_GETENV])
   GNULIB_SETENV=0;        AC_SUBST([GNULIB_SETENV])
   GNULIB_STRTOD=0;        AC_SUBST([GNULIB_STRTOD])
   GNULIB_STRTOLL=0;       AC_SUBST([GNULIB_STRTOLL])
@@ -88,6 +89,7 @@ AC_DEFUN([gl_STDLIB_H_DEFAULTS],
   HAVE_RANDOM_R=1;           AC_SUBST([HAVE_RANDOM_R])
   HAVE_REALPATH=1;           AC_SUBST([HAVE_REALPATH])
   HAVE_RPMATCH=1;            AC_SUBST([HAVE_RPMATCH])
+  HAVE_SECURE_GETENV=1;      AC_SUBST([HAVE_SECURE_GETENV])
   HAVE_SETENV=1;             AC_SUBST([HAVE_SETENV])
   HAVE_DECL_SETENV=1;        AC_SUBST([HAVE_DECL_SETENV])
   HAVE_STRTOD=1;             AC_SUBST([HAVE_STRTOD])