Merge from gnulib

This incorporates:
2017-05-13 largefile: Simplify
2017-05-13 largefile: Improve and document
2017-05-13 truncate: New module
2017-05-13 windows-stat-timespec: New module
2017-05-13 windows-stat-override: New module
2017-05-11 getopt-posix: port to mingw
2017-05-11 gettimeofday: Increase precision on mingw
2017-05-10 time: Fix missing initialization of HAVE_TIMEZONE_T
2017-05-10 Implement a way to opt out from MSVC support
2017-05-09 tzset: Expand comment about TZ problem on native Windows
* build-aux/config.guess, lib/dup2.c, lib/fcntl.c, lib/fsync.c:
* lib/getdtablesize.c, lib/getopt.c, lib/gettimeofday.c:
* lib/mktime.c, lib/stat-time.h, lib/sys_stat.in.h, lib/unistd.in.h:
* lib/utimens.c, m4/gettimeofday.m4, m4/largefile.m4:
* m4/sys_stat_h.m4, m4/sys_time_h.m4, m4/time_h.m4, m4/time_rz.m4:
* m4/unistd_h.m4: Copy from gnulib.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.

21 files changed, 343 insertions, 128 deletions

diff --git a/build-aux/config.guess b/build-aux/config.guess
index 69ed3e573bb..faa63aa9429 100755
--- a/build-aux/config.guess
+++ b/build-aux/config.guess
@@ -2,7 +2,7 @@
 # Attempt to guess a canonical system name.
 #   Copyright 1992-2017 Free Software Foundation, Inc.
 
-timestamp='2017-03-05'
+timestamp='2017-05-11'
 
 # This file is free software; you can redistribute it and/or modify it
 # under the terms of the GNU General Public License as published by
@@ -1335,16 +1335,16 @@ EOF
     *:QNX:*:4*)
 	echo i386-pc-qnx
 	exit ;;
-    NEO-?:NONSTOP_KERNEL:*:*)
+    NEO-*:NONSTOP_KERNEL:*:*)
 	echo neo-tandem-nsk${UNAME_RELEASE}
 	exit ;;
     NSE-*:NONSTOP_KERNEL:*:*)
 	echo nse-tandem-nsk${UNAME_RELEASE}
 	exit ;;
-    NSR-?:NONSTOP_KERNEL:*:*)
+    NSR-*:NONSTOP_KERNEL:*:*)
 	echo nsr-tandem-nsk${UNAME_RELEASE}
 	exit ;;
-    NSX-?:NONSTOP_KERNEL:*:*)
+    NSX-*:NONSTOP_KERNEL:*:*)
 	echo nsx-tandem-nsk${UNAME_RELEASE}
 	exit ;;
     *:NonStop-UX:*:*)
diff --git a/lib/dup2.c b/lib/dup2.c
index c0c7cadf4a8..002dc8c76cb 100644
--- a/lib/dup2.c
+++ b/lib/dup2.c
@@ -35,10 +35,39 @@
 #  define WIN32_LEAN_AND_MEAN
 #  include <windows.h>
 
-#  include "msvc-inval.h"
+#  if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+#   include "msvc-inval.h"
+#  endif
 
 /* Get _get_osfhandle.  */
-#  include "msvc-nothrow.h"
+#  if GNULIB_MSVC_NOTHROW
+#   include "msvc-nothrow.h"
+#  else
+#   include <io.h>
+#  endif
+
+#  if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+static int
+dup2_nothrow (int fd, int desired_fd)
+{
+  int result;
+
+  TRY_MSVC_INVAL
+    {
+      result = dup2 (fd, desired_fd);
+    }
+  CATCH_MSVC_INVAL
+    {
+      errno = EBADF;
+      result = -1;
+    }
+  DONE_MSVC_INVAL;
+
+  return result;
+}
+#  else
+#   define dup2_nothrow dup2
+#  endif
 
 static int
 ms_windows_dup2 (int fd, int desired_fd)
@@ -66,16 +95,7 @@ ms_windows_dup2 (int fd, int desired_fd)
       return -1;
     }
 
-  TRY_MSVC_INVAL
-    {
-      result = dup2 (fd, desired_fd);
-    }
-  CATCH_MSVC_INVAL
-    {
-      errno = EBADF;
-      result = -1;
-    }
-  DONE_MSVC_INVAL;
+  result = dup2_nothrow (fd, desired_fd);
 
   if (result == 0)
     result = desired_fd;
diff --git a/lib/fcntl.c b/lib/fcntl.c
index afe15468ffa..d4dd144e05d 100644
--- a/lib/fcntl.c
+++ b/lib/fcntl.c
@@ -38,7 +38,11 @@
 # include <windows.h>
 
 /* Get _get_osfhandle.  */
-# include "msvc-nothrow.h"
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
 
 /* Upper bound on getdtablesize().  See lib/getdtablesize.c.  */
 # define OPEN_MAX_MAX 0x10000
diff --git a/lib/fsync.c b/lib/fsync.c
index 46dd59b3d2c..5a4945ef2bf 100644
--- a/lib/fsync.c
+++ b/lib/fsync.c
@@ -34,7 +34,11 @@
 # include <errno.h>
 
 /* Get _get_osfhandle.  */
-# include "msvc-nothrow.h"
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
 
 int
 fsync (int fd)
diff --git a/lib/getdtablesize.c b/lib/getdtablesize.c
index 7fabb51e2c6..c356cf4aa97 100644
--- a/lib/getdtablesize.c
+++ b/lib/getdtablesize.c
@@ -24,7 +24,9 @@
 
 # include <stdio.h>
 
-# include "msvc-inval.h"
+# if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+#  include "msvc-inval.h"
+# endif
 
 # if HAVE_MSVC_INVALID_PARAMETER_HANDLER
 static int
@@ -44,7 +46,8 @@ _setmaxstdio_nothrow (int newmax)
 
   return result;
 }
-#  define _setmaxstdio _setmaxstdio_nothrow
+# else
+#  define _setmaxstdio_nothrow _setmaxstdio
 # endif
 
 /* Cache for the previous getdtablesize () result.  Safe to cache because
@@ -76,9 +79,9 @@ getdtablesize (void)
          freed when we call _setmaxstdio with the original value.  */
       int orig_max_stdio = _getmaxstdio ();
       unsigned int bound;
-      for (bound = 0x10000; _setmaxstdio (bound) < 0; bound = bound / 2)
+      for (bound = 0x10000; _setmaxstdio_nothrow (bound) < 0; bound = bound / 2)
         ;
-      _setmaxstdio (orig_max_stdio);
+      _setmaxstdio_nothrow (orig_max_stdio);
       dtablesize = bound;
     }
   return dtablesize;
diff --git a/lib/getopt.c b/lib/getopt.c
index a7db39b68df..9a2867db277 100644
--- a/lib/getopt.c
+++ b/lib/getopt.c
@@ -45,7 +45,8 @@
 # define _(msgid) gettext (msgid)
 /* When used standalone, flockfile and funlockfile might not be
    available.  */
-# ifndef _POSIX_THREAD_SAFE_FUNCTIONS
+# if (!defined _POSIX_THREAD_SAFE_FUNCTIONS \
+      || ((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__))
 #  define flockfile(fp) /* nop */
 #  define funlockfile(fp) /* nop */
 # endif
diff --git a/lib/gettimeofday.c b/lib/gettimeofday.c
index 1039f77d182..8ae7622af31 100644
--- a/lib/gettimeofday.c
+++ b/lib/gettimeofday.c
@@ -64,42 +64,20 @@ int
 gettimeofday (struct timeval *restrict tv, void *restrict tz)
 {
 #undef gettimeofday
-#if HAVE_GETTIMEOFDAY
-# if GETTIMEOFDAY_CLOBBERS_LOCALTIME
-  /* Save and restore the contents of the buffer used for localtime's
-     result around the call to gettimeofday.  */
-  struct tm save = *localtime_buffer_addr;
-# endif
-
-# if defined timeval /* 'struct timeval' overridden by gnulib?  */
-#  undef timeval
-  struct timeval otv;
-  int result = gettimeofday (&otv, (struct timezone *) tz);
-  if (result == 0)
-    {
-      tv->tv_sec = otv.tv_sec;
-      tv->tv_usec = otv.tv_usec;
-    }
-# else
-  int result = gettimeofday (tv, (struct timezone *) tz);
-# endif
-
-# if GETTIMEOFDAY_CLOBBERS_LOCALTIME
-  *localtime_buffer_addr = save;
-# endif
-
-  return result;
-
-#else
-
-# ifdef WINDOWS_NATIVE
+#ifdef WINDOWS_NATIVE
 
   /* On native Windows, there are two ways to get the current time:
      GetSystemTimeAsFileTime
      <https://msdn.microsoft.com/en-us/library/ms724397.aspx>
      or
      GetSystemTimePreciseAsFileTime
-     <https://msdn.microsoft.com/en-us/library/hh706895.aspx>.  */
+     <https://msdn.microsoft.com/en-us/library/hh706895.aspx>.
+     GetSystemTimeAsFileTime produces values that jump by increments of
+     15.627 milliseconds (!) on average.
+     Whereas GetSystemTimePreciseAsFileTime values usually jump by 1 or 2
+     microseconds.
+     More discussion on this topic:
+     <http://www.windowstimestamp.com/description>.  */
   FILETIME current_time;
 
   if (!initialized)
@@ -122,6 +100,36 @@ gettimeofday (struct timeval *restrict tv, void *restrict tz)
   tv->tv_sec = microseconds_since_1970 / (ULONGLONG) 1000000;
   tv->tv_usec = microseconds_since_1970 % (ULONGLONG) 1000000;
 
+  return 0;
+
+#else
+
+# if HAVE_GETTIMEOFDAY
+#  if GETTIMEOFDAY_CLOBBERS_LOCALTIME
+  /* Save and restore the contents of the buffer used for localtime's
+     result around the call to gettimeofday.  */
+  struct tm save = *localtime_buffer_addr;
+#  endif
+
+#  if defined timeval /* 'struct timeval' overridden by gnulib?  */
+#   undef timeval
+  struct timeval otv;
+  int result = gettimeofday (&otv, (struct timezone *) tz);
+  if (result == 0)
+    {
+      tv->tv_sec = otv.tv_sec;
+      tv->tv_usec = otv.tv_usec;
+    }
+#  else
+  int result = gettimeofday (tv, (struct timezone *) tz);
+#  endif
+
+#  if GETTIMEOFDAY_CLOBBERS_LOCALTIME
+  *localtime_buffer_addr = save;
+#  endif
+
+  return result;
+
 # else
 
 #  if !defined OK_TO_USE_1S_CLOCK
@@ -131,9 +139,8 @@ gettimeofday (struct timeval *restrict tv, void *restrict tz)
   tv->tv_sec = time (NULL);
   tv->tv_usec = 0;
 
-# endif
-
   return 0;
 
+# endif
 #endif
 }
diff --git a/lib/gnulib.mk.in b/lib/gnulib.mk.in
index 51ae1891244..d4afafbecc9 100644
--- a/lib/gnulib.mk.in
+++ b/lib/gnulib.mk.in
@@ -225,6 +225,7 @@ GNULIB_OBSTACK_PRINTF_POSIX = @GNULIB_OBSTACK_PRINTF_POSIX@
 GNULIB_OPEN = @GNULIB_OPEN@
 GNULIB_OPENAT = @GNULIB_OPENAT@
 GNULIB_OPENDIR = @GNULIB_OPENDIR@
+GNULIB_OVERRIDES_STRUCT_STAT = @GNULIB_OVERRIDES_STRUCT_STAT@
 GNULIB_OVERRIDES_WINT_T = @GNULIB_OVERRIDES_WINT_T@
 GNULIB_PCLOSE = @GNULIB_PCLOSE@
 GNULIB_PERROR = @GNULIB_PERROR@
@@ -306,6 +307,7 @@ GNULIB_TIMEGM = @GNULIB_TIMEGM@
 GNULIB_TIME_R = @GNULIB_TIME_R@
 GNULIB_TIME_RZ = @GNULIB_TIME_RZ@
 GNULIB_TMPFILE = @GNULIB_TMPFILE@
+GNULIB_TRUNCATE = @GNULIB_TRUNCATE@
 GNULIB_TTYNAME_R = @GNULIB_TTYNAME_R@
 GNULIB_TZSET = @GNULIB_TZSET@
 GNULIB_UNISTD_H_NONBLOCKING = @GNULIB_UNISTD_H_NONBLOCKING@
@@ -504,6 +506,7 @@ HAVE_SYS_TIME_H = @HAVE_SYS_TIME_H@
 HAVE_SYS_TYPES_H = @HAVE_SYS_TYPES_H@
 HAVE_TIMEGM = @HAVE_TIMEGM@
 HAVE_TIMEZONE_T = @HAVE_TIMEZONE_T@
+HAVE_TRUNCATE = @HAVE_TRUNCATE@
 HAVE_TYPE_VOLATILE_SIG_ATOMIC_T = @HAVE_TYPE_VOLATILE_SIG_ATOMIC_T@
 HAVE_TZSET = @HAVE_TZSET@
 HAVE_UNISTD_H = @HAVE_UNISTD_H@
@@ -781,6 +784,7 @@ REPLACE_SYMLINK = @REPLACE_SYMLINK@
 REPLACE_SYMLINKAT = @REPLACE_SYMLINKAT@
 REPLACE_TIMEGM = @REPLACE_TIMEGM@
 REPLACE_TMPFILE = @REPLACE_TMPFILE@
+REPLACE_TRUNCATE = @REPLACE_TRUNCATE@
 REPLACE_TTYNAME_R = @REPLACE_TTYNAME_R@
 REPLACE_TZSET = @REPLACE_TZSET@
 REPLACE_UNLINK = @REPLACE_UNLINK@
@@ -834,6 +838,7 @@ WERROR_CFLAGS = @WERROR_CFLAGS@
 WIDGET_OBJ = @WIDGET_OBJ@
 WINDOWS_64_BIT_OFF_T = @WINDOWS_64_BIT_OFF_T@
 WINDOWS_64_BIT_ST_SIZE = @WINDOWS_64_BIT_ST_SIZE@
+WINDOWS_STAT_TIMESPEC = @WINDOWS_STAT_TIMESPEC@
 WINDOW_SYSTEM_OBJ = @WINDOW_SYSTEM_OBJ@
 WINDRES = @WINDRES@
 WINT_T_SUFFIX = @WINT_T_SUFFIX@
@@ -2586,6 +2591,7 @@ sys/stat.h: sys_stat.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNU
 	      -e 's|@''PRAGMA_COLUMNS''@|@PRAGMA_COLUMNS@|g' \
 	      -e 's|@''NEXT_SYS_STAT_H''@|$(NEXT_SYS_STAT_H)|g' \
 	      -e 's|@''WINDOWS_64_BIT_ST_SIZE''@|$(WINDOWS_64_BIT_ST_SIZE)|g' \
+	      -e 's|@''WINDOWS_STAT_TIMESPEC''@|$(WINDOWS_STAT_TIMESPEC)|g' \
 	      -e 's/@''GNULIB_FCHMODAT''@/$(GNULIB_FCHMODAT)/g' \
 	      -e 's/@''GNULIB_FSTAT''@/$(GNULIB_FSTAT)/g' \
 	      -e 's/@''GNULIB_FSTATAT''@/$(GNULIB_FSTATAT)/g' \
@@ -2599,6 +2605,7 @@ sys/stat.h: sys_stat.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNU
 	      -e 's/@''GNULIB_MKNODAT''@/$(GNULIB_MKNODAT)/g' \
 	      -e 's/@''GNULIB_STAT''@/$(GNULIB_STAT)/g' \
 	      -e 's/@''GNULIB_UTIMENSAT''@/$(GNULIB_UTIMENSAT)/g' \
+	      -e 's/@''GNULIB_OVERRIDES_STRUCT_STAT''@/$(GNULIB_OVERRIDES_STRUCT_STAT)/g' \
 	      -e 's|@''HAVE_FCHMODAT''@|$(HAVE_FCHMODAT)|g' \
 	      -e 's|@''HAVE_FSTATAT''@|$(HAVE_FSTATAT)|g' \
 	      -e 's|@''HAVE_FUTIMENS''@|$(HAVE_FUTIMENS)|g' \
@@ -2893,6 +2900,7 @@ unistd.h: unistd.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H
 	      -e 's/@''GNULIB_SLEEP''@/$(GNULIB_SLEEP)/g' \
 	      -e 's/@''GNULIB_SYMLINK''@/$(GNULIB_SYMLINK)/g' \
 	      -e 's/@''GNULIB_SYMLINKAT''@/$(GNULIB_SYMLINKAT)/g' \
+	      -e 's/@''GNULIB_TRUNCATE''@/$(GNULIB_TRUNCATE)/g' \
 	      -e 's/@''GNULIB_TTYNAME_R''@/$(GNULIB_TTYNAME_R)/g' \
 	      -e 's/@''GNULIB_UNISTD_H_GETOPT''@/0$(GNULIB_GL_UNISTD_H_GETOPT)/g' \
 	      -e 's/@''GNULIB_UNISTD_H_NONBLOCKING''@/$(GNULIB_UNISTD_H_NONBLOCKING)/g' \
@@ -2930,6 +2938,7 @@ unistd.h: unistd.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H
 	      -e 's|@''HAVE_SLEEP''@|$(HAVE_SLEEP)|g' \
 	      -e 's|@''HAVE_SYMLINK''@|$(HAVE_SYMLINK)|g' \
 	      -e 's|@''HAVE_SYMLINKAT''@|$(HAVE_SYMLINKAT)|g' \
+	      -e 's|@''HAVE_TRUNCATE''@|$(HAVE_TRUNCATE)|g' \
 	      -e 's|@''HAVE_UNLINKAT''@|$(HAVE_UNLINKAT)|g' \
 	      -e 's|@''HAVE_USLEEP''@|$(HAVE_USLEEP)|g' \
 	      -e 's|@''HAVE_DECL_ENVIRON''@|$(HAVE_DECL_ENVIRON)|g' \
@@ -2971,6 +2980,7 @@ unistd.h: unistd.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H
 	      -e 's|@''REPLACE_SLEEP''@|$(REPLACE_SLEEP)|g' \
 	      -e 's|@''REPLACE_SYMLINK''@|$(REPLACE_SYMLINK)|g' \
 	      -e 's|@''REPLACE_SYMLINKAT''@|$(REPLACE_SYMLINKAT)|g' \
+	      -e 's|@''REPLACE_TRUNCATE''@|$(REPLACE_TRUNCATE)|g' \
 	      -e 's|@''REPLACE_TTYNAME_R''@|$(REPLACE_TTYNAME_R)|g' \
 	      -e 's|@''REPLACE_UNLINK''@|$(REPLACE_UNLINK)|g' \
 	      -e 's|@''REPLACE_UNLINKAT''@|$(REPLACE_UNLINKAT)|g' \
diff --git a/lib/mktime.c b/lib/mktime.c
index 06d5916e910..058ab65c03e 100644
--- a/lib/mktime.c
+++ b/lib/mktime.c
@@ -491,9 +491,28 @@ time_t
 mktime (struct tm *tp)
 {
 # if NEED_MKTIME_WINDOWS
-  /* If the environment variable TZ has been set by Cygwin, neutralize it.
-     The Microsoft CRT interprets TZ differently than Cygwin and produces
-     incorrect results if TZ has the syntax used by Cygwin.  */
+  /* Rectify the value of the environment variable TZ.
+     There are four possible kinds of such values:
+       - Traditional US time zone names, e.g. "PST8PDT".  Syntax: see
+         <https://msdn.microsoft.com/en-us/library/90s5c885.aspx>
+       - Time zone names based on geography, that contain one or more
+         slashes, e.g. "Europe/Moscow".
+       - Time zone names based on geography, without slashes, e.g.
+         "Singapore".
+       - Time zone names that contain explicit DST rules.  Syntax: see
+         <http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html#tag_08_03>
+     The Microsoft CRT understands only the first kind.  It produces incorrect
+     results if the value of TZ is of the other kinds.
+     But in a Cygwin environment, /etc/profile.d/tzset.sh sets TZ to a value
+     of the second kind for most geographies, or of the first kind in a few
+     other geographies.  If it is of the second kind, neutralize it.  For the
+     Microsoft CRT, an absent or empty TZ means the time zone that the user
+     has set in the Windows Control Panel.
+     If the value of TZ is of the third or fourth kind -- Cygwin programs
+     understand these syntaxes as well --, it does not matter whether we
+     neutralize it or not, since these values occur only when a Cygwin user
+     has set TZ explicitly; this case is 1. rare and 2. under the user's
+     responsibility.  */
   const char *tz = getenv ("TZ");
   if (tz != NULL && strchr (tz, '/') != NULL)
     _putenv ("TZ=");
diff --git a/lib/stat-time.h b/lib/stat-time.h
index 154d62a01f5..88dcc7f3e0d 100644
--- a/lib/stat-time.h
+++ b/lib/stat-time.h
@@ -43,8 +43,8 @@ extern "C" {
    time respectively.
 
    These macros are private to stat-time.h.  */
-#if defined HAVE_STRUCT_STAT_ST_ATIM_TV_NSEC
-# ifdef TYPEOF_STRUCT_STAT_ST_ATIM_IS_STRUCT_TIMESPEC
+#if _GL_WINDOWS_STAT_TIMESPEC || defined HAVE_STRUCT_STAT_ST_ATIM_TV_NSEC
+# if _GL_WINDOWS_STAT_TIMESPEC || defined TYPEOF_STRUCT_STAT_ST_ATIM_IS_STRUCT_TIMESPEC
 #  define STAT_TIMESPEC(st, st_xtim) ((st)->st_xtim)
 # else
 #  define STAT_TIMESPEC_NS(st, st_xtim) ((st)->st_xtim.tv_nsec)
diff --git a/lib/sys_stat.in.h b/lib/sys_stat.in.h
index d5ca343437f..1831740900b 100644
--- a/lib/sys_stat.in.h
+++ b/lib/sys_stat.in.h
@@ -1,4 +1,4 @@
-/* Provide a more complete sys/stat header file.
+/* Provide a more complete sys/stat.h header file.
    Copyright (C) 2005-2017 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
@@ -72,6 +72,75 @@
 # define stat _stati64
 #endif
 
+/* Optionally, override 'struct stat' on native Windows.  */
+#if @GNULIB_OVERRIDES_STRUCT_STAT@
+
+# undef stat
+# if @GNULIB_STAT@
+#  define stat rpl_stat
+# else
+   /* Provoke a clear link error if stat() is used as a function and
+      module 'stat' is not in use.  */
+#  define stat stat_used_without_requesting_gnulib_module_stat
+# endif
+
+# if !GNULIB_defined_struct_stat
+struct stat
+{
+  dev_t st_dev;
+  ino_t st_ino;
+  mode_t st_mode;
+  nlink_t st_nlink;
+#  if 0
+  uid_t st_uid;
+#  else /* uid_t is not defined by default on native Windows.  */
+  short st_uid;
+#  endif
+#  if 0
+  gid_t st_gid;
+#  else /* gid_t is not defined by default on native Windows.  */
+  short st_gid;
+#  endif
+  dev_t st_rdev;
+  off_t st_size;
+#  if 0
+  blksize_t st_blksize;
+  blkcnt_t st_blocks;
+#  endif
+
+#  if @WINDOWS_STAT_TIMESPEC@
+  struct timespec st_atim;
+  struct timespec st_mtim;
+  struct timespec st_ctim;
+#  else
+  time_t st_atime;
+  time_t st_mtime;
+  time_t st_ctime;
+#  endif
+};
+#  if @WINDOWS_STAT_TIMESPEC@
+#   define st_atime st_atim.tv_sec
+#   define st_mtime st_mtim.tv_sec
+#   define st_ctime st_ctim.tv_sec
+    /* Indicator, for gnulib internal purposes.  */
+#   define _GL_WINDOWS_STAT_TIMESPEC 1
+#  endif
+#  define GNULIB_defined_struct_stat 1
+# endif
+
+/* Other possible values of st_mode.  */
+# if 0
+#  define _S_IFBLK  0x6000
+# endif
+# if 0
+#  define _S_IFLNK  0xA000
+# endif
+# if 0
+#  define _S_IFSOCK 0xC000
+# endif
+
+#endif
+
 #ifndef S_IFIFO
 # ifdef _S_IFIFO
 #  define S_IFIFO _S_IFIFO
@@ -345,6 +414,9 @@ _GL_CXXALIAS_RPL (fstat, int, (int fd, struct stat *buf));
 _GL_CXXALIAS_SYS (fstat, int, (int fd, struct stat *buf));
 # endif
 _GL_CXXALIASWARN (fstat);
+#elif @GNULIB_OVERRIDES_STRUCT_STAT@
+# undef fstat
+# define fstat fstat_used_without_requesting_gnulib_module_fstat
 #elif @WINDOWS_64_BIT_ST_SIZE@
 /* Above, we define stat to _stati64.  */
 # define fstat _fstati64
@@ -378,6 +450,9 @@ _GL_CXXALIAS_SYS (fstatat, int,
                   (int fd, char const *name, struct stat *st, int flags));
 # endif
 _GL_CXXALIASWARN (fstatat);
+#elif @GNULIB_OVERRIDES_STRUCT_STAT@
+# undef fstatat
+# define fstatat fstatat_used_without_requesting_gnulib_module_fstatat
 #elif defined GNULIB_POSIXCHECK
 # undef fstatat
 # if HAVE_RAW_DECL_FSTATAT
@@ -476,6 +551,9 @@ _GL_CXXALIAS_SYS (lstat, int, (const char *name, struct stat *buf));
 # if @HAVE_LSTAT@
 _GL_CXXALIASWARN (lstat);
 # endif
+#elif @GNULIB_OVERRIDES_STRUCT_STAT@
+# undef lstat
+# define lstat lstat_used_without_requesting_gnulib_module_lstat
 #elif defined GNULIB_POSIXCHECK
 # undef lstat
 # if HAVE_RAW_DECL_LSTAT
@@ -625,63 +703,69 @@ _GL_WARN_ON_USE (mknodat, "mknodat is not portable - "
 
 #if @GNULIB_STAT@
 # if @REPLACE_STAT@
-/* We can't use the object-like #define stat rpl_stat, because of
-   struct stat.  This means that rpl_stat will not be used if the user
-   does (stat)(a,b).  Oh well.  */
-#  if defined _AIX && defined stat && defined _LARGE_FILES
-    /* With _LARGE_FILES defined, AIX (only) defines stat to stat64,
-       so we have to replace stat64() instead of stat(). */
-#   undef stat64
-#   define stat64(name, st) rpl_stat (name, st)
-#  elif @WINDOWS_64_BIT_ST_SIZE@
-    /* Above, we define stat to _stati64.  */
-#   if defined __MINGW32__ && defined _stati64
-#    ifndef _USE_32BIT_TIME_T
-      /* The system headers define _stati64 to _stat64.  */
-#     undef _stat64
-#     define _stat64(name, st) rpl_stat (name, st)
+#  if !@GNULIB_OVERRIDES_STRUCT_STAT@
+    /* We can't use the object-like #define stat rpl_stat, because of
+       struct stat.  This means that rpl_stat will not be used if the user
+       does (stat)(a,b).  Oh well.  */
+#   if defined _AIX && defined stat && defined _LARGE_FILES
+     /* With _LARGE_FILES defined, AIX (only) defines stat to stat64,
+        so we have to replace stat64() instead of stat(). */
+#    undef stat64
+#    define stat64(name, st) rpl_stat (name, st)
+#   elif @WINDOWS_64_BIT_ST_SIZE@
+     /* Above, we define stat to _stati64.  */
+#    if defined __MINGW32__ && defined _stati64
+#     ifndef _USE_32BIT_TIME_T
+       /* The system headers define _stati64 to _stat64.  */
+#      undef _stat64
+#      define _stat64(name, st) rpl_stat (name, st)
+#     endif
+#    elif defined _MSC_VER && defined _stati64
+#     ifdef _USE_32BIT_TIME_T
+       /* The system headers define _stati64 to _stat32i64.  */
+#      undef _stat32i64
+#      define _stat32i64(name, st) rpl_stat (name, st)
+#     else
+       /* The system headers define _stati64 to _stat64.  */
+#      undef _stat64
+#      define _stat64(name, st) rpl_stat (name, st)
+#     endif
+#    else
+#     undef _stati64
+#     define _stati64(name, st) rpl_stat (name, st)
 #    endif
-#   elif defined _MSC_VER && defined _stati64
+#   elif defined __MINGW32__ && defined stat
 #    ifdef _USE_32BIT_TIME_T
-      /* The system headers define _stati64 to _stat32i64.  */
+      /* The system headers define stat to _stat32i64.  */
 #     undef _stat32i64
 #     define _stat32i64(name, st) rpl_stat (name, st)
 #    else
-      /* The system headers define _stati64 to _stat64.  */
+      /* The system headers define stat to _stat64.  */
 #     undef _stat64
 #     define _stat64(name, st) rpl_stat (name, st)
 #    endif
-#   else
-#    undef _stati64
-#    define _stati64(name, st) rpl_stat (name, st)
-#   endif
-#  elif defined __MINGW32__ && defined stat
-#   ifdef _USE_32BIT_TIME_T
-     /* The system headers define stat to _stat32i64.  */
-#    undef _stat32i64
-#    define _stat32i64(name, st) rpl_stat (name, st)
-#   else
-     /* The system headers define stat to _stat64.  */
-#    undef _stat64
-#    define _stat64(name, st) rpl_stat (name, st)
-#   endif
-#  elif defined _MSC_VER && defined stat
-#   ifdef _USE_32BIT_TIME_T
-     /* The system headers define stat to _stat32.  */
-#    undef _stat32
-#    define _stat32(name, st) rpl_stat (name, st)
-#   else
-     /* The system headers define stat to _stat64i32.  */
-#    undef _stat64i32
-#    define _stat64i32(name, st) rpl_stat (name, st)
-#   endif
-#  else /* !(_AIX ||__MINGW32__ ||  _MSC_VER) */
-#   undef stat
-#   define stat(name, st) rpl_stat (name, st)
-#  endif /* !_LARGE_FILES */
+#   elif defined _MSC_VER && defined stat
+#    ifdef _USE_32BIT_TIME_T
+      /* The system headers define stat to _stat32.  */
+#     undef _stat32
+#     define _stat32(name, st) rpl_stat (name, st)
+#    else
+      /* The system headers define stat to _stat64i32.  */
+#     undef _stat64i32
+#     define _stat64i32(name, st) rpl_stat (name, st)
+#    endif
+#   else /* !(_AIX || __MINGW32__ || _MSC_VER) */
+#    undef stat
+#    define stat(name, st) rpl_stat (name, st)
+#   endif /* !_LARGE_FILES */
+#  endif /* !@GNULIB_OVERRIDES_STRUCT_STAT@ */
 _GL_EXTERN_C int stat (const char *name, struct stat *buf)
                       _GL_ARG_NONNULL ((1, 2));
 # endif
+#elif @GNULIB_OVERRIDES_STRUCT_STAT@
+/* see above:
+  #define stat stat_used_without_requesting_gnulib_module_stat
+ */
 #elif defined GNULIB_POSIXCHECK
 # undef stat
 # if HAVE_RAW_DECL_STAT
diff --git a/lib/unistd.in.h b/lib/unistd.in.h
index cb9321e502d..f366caffa55 100644
--- a/lib/unistd.in.h
+++ b/lib/unistd.in.h
@@ -1457,6 +1457,36 @@ _GL_WARN_ON_USE (symlinkat, "symlinkat is not portable - "
 #endif
 
 
+#if @GNULIB_TRUNCATE@
+/* Change the size of the file designated by FILENAME to become equal to LENGTH.
+   Return 0 if successful, otherwise -1 and errno set.
+   See the POSIX:2008 specification
+   <http://pubs.opengroup.org/onlinepubs/9699919799/functions/truncate.html>.  */
+# if @REPLACE_TRUNCATE@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef truncate
+#   define truncate rpl_truncate
+#  endif
+_GL_FUNCDECL_RPL (truncate, int, (const char *filename, off_t length)
+                                 _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (truncate, int, (const char *filename, off_t length));
+# else
+#  if !@HAVE_TRUNCATE@
+_GL_FUNCDECL_SYS (truncate, int, (const char *filename, off_t length)
+                                 _GL_ARG_NONNULL ((1)));
+#  endif
+_GL_CXXALIAS_SYS (truncate, int, (const char *filename, off_t length));
+# endif
+_GL_CXXALIASWARN (truncate);
+#elif defined GNULIB_POSIXCHECK
+# undef truncate
+# if HAVE_RAW_DECL_TRUNCATE
+_GL_WARN_ON_USE (truncate, "truncate is unportable - "
+                 "use gnulib module truncate for portability");
+# endif
+#endif
+
+
 #if @GNULIB_TTYNAME_R@
 /* Store at most BUFLEN characters of the pathname of the terminal FD is
    open on in BUF.  Return 0 on success, otherwise an error number.  */
diff --git a/lib/utimens.c b/lib/utimens.c
index b4bfa8e3222..ff4eab073c1 100644
--- a/lib/utimens.c
+++ b/lib/utimens.c
@@ -44,7 +44,11 @@
 # define USE_SETFILETIME
 # define WIN32_LEAN_AND_MEAN
 # include <windows.h>
-# include "msvc-nothrow.h"
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
 #endif
 
 /* Avoid recursion with rpl_futimens or rpl_utimensat.  */
diff --git a/m4/gettimeofday.m4 b/m4/gettimeofday.m4
index 34adc64778f..8ee206eea24 100644
--- a/m4/gettimeofday.m4
+++ b/m4/gettimeofday.m4
@@ -1,4 +1,4 @@
-# serial 22
+# serial 23
 
 # Copyright (C) 2001-2003, 2005, 2007, 2009-2017 Free Software Foundation, Inc.
 # This file is free software; the Free Software Foundation
@@ -9,9 +9,10 @@ dnl From Jim Meyering.
 
 AC_DEFUN([gl_FUNC_GETTIMEOFDAY],
 [
+  AC_REQUIRE([gl_HEADER_SYS_TIME_H_DEFAULTS])
   AC_REQUIRE([AC_C_RESTRICT])
+  AC_REQUIRE([AC_CANONICAL_HOST])
   AC_REQUIRE([gl_HEADER_SYS_TIME_H])
-  AC_REQUIRE([gl_HEADER_SYS_TIME_H_DEFAULTS])
   AC_CHECK_FUNCS_ONCE([gettimeofday])
 
   gl_gettimeofday_timezone=void
@@ -54,6 +55,11 @@ int gettimeofday (struct timeval *restrict, struct timezone *restrict);
     if test $REPLACE_STRUCT_TIMEVAL = 1; then
       REPLACE_GETTIMEOFDAY=1
     fi
+    dnl On mingw, the original gettimeofday has only a precision of 15.6
+    dnl milliseconds. So override it.
+    case "$host_os" in
+      mingw*) REPLACE_GETTIMEOFDAY=1 ;;
+    esac
   fi
   AC_DEFINE_UNQUOTED([GETTIMEOFDAY_TIMEZONE], [$gl_gettimeofday_timezone],
     [Define this to 'void' or 'struct timezone' to match the system's
diff --git a/m4/gnulib-comp.m4 b/m4/gnulib-comp.m4
index 74b197c8633..8295e483582 100644
--- a/m4/gnulib-comp.m4
+++ b/m4/gnulib-comp.m4
@@ -391,7 +391,7 @@ AC_DEFUN([gl_INIT],
   fi
   gl_TIME_MODULE_INDICATOR([time_r])
   gl_TIME_RZ
-  if test "$HAVE_TIMEZONE_T" = 0; then
+  if test $HAVE_TIMEZONE_T = 0; then
     AC_LIBOBJ([time_rz])
   fi
   gl_TIME_MODULE_INDICATOR([time_rz])
diff --git a/m4/largefile.m4 b/m4/largefile.m4
index 790f7c0ad39..edc1a9b41ba 100644
--- a/m4/largefile.m4
+++ b/m4/largefile.m4
@@ -126,9 +126,24 @@ AC_DEFUN([gl_LARGEFILE],
       else
         WINDOWS_64_BIT_OFF_T=0
       fi
-      dnl But all native Windows platforms (including mingw64) have a 32-bit
-      dnl st_size member in 'struct stat'.
-      WINDOWS_64_BIT_ST_SIZE=1
+      dnl Some mingw versions define, if _FILE_OFFSET_BITS=64, 'struct stat'
+      dnl to 'struct _stat32i64' or 'struct _stat64' (depending on
+      dnl _USE_32BIT_TIME_T), which has a 32-bit st_size member.
+      AC_CACHE_CHECK([for 64-bit st_size], [gl_cv_member_st_size_64],
+        [AC_COMPILE_IFELSE(
+           [AC_LANG_PROGRAM(
+              [[#include <sys/types.h>
+                struct stat buf;
+                int verify_st_size_size[sizeof (buf.st_size) >= 8 ? 1 : -1];
+              ]],
+              [[]])],
+           [gl_cv_member_st_size_64=yes], [gl_cv_member_st_size_64=no])
+        ])
+      if test $gl_cv_member_st_size_64 = no; then
+        WINDOWS_64_BIT_ST_SIZE=1
+      else
+        WINDOWS_64_BIT_ST_SIZE=0
+      fi
       ;;
     *)
       dnl Nothing to do on gnulib's side.
diff --git a/m4/sys_stat_h.m4 b/m4/sys_stat_h.m4
index 1e34ac40da1..89342789828 100644
--- a/m4/sys_stat_h.m4
+++ b/m4/sys_stat_h.m4
@@ -1,4 +1,4 @@
-# sys_stat_h.m4 serial 28   -*- Autoconf -*-
+# sys_stat_h.m4 serial 31   -*- Autoconf -*-
 dnl Copyright (C) 2006-2017 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -19,18 +19,21 @@ AC_DEFUN([gl_HEADER_SYS_STAT_H],
   dnl Ensure the type mode_t gets defined.
   AC_REQUIRE([AC_TYPE_MODE_T])
 
-  dnl Whether to override 'struct stat'.
+  dnl Whether to enable precise timestamps in 'struct stat'.
+  m4_ifdef([gl_WINDOWS_STAT_TIMESPEC], [
+    AC_REQUIRE([gl_WINDOWS_STAT_TIMESPEC])
+  ], [
+    WINDOWS_STAT_TIMESPEC=0
+  ])
+  AC_SUBST([WINDOWS_STAT_TIMESPEC])
+
+  dnl Whether to ensure that struct stat.st_size is 64-bit wide.
   m4_ifdef([gl_LARGEFILE], [
     AC_REQUIRE([gl_LARGEFILE])
   ], [
     WINDOWS_64_BIT_ST_SIZE=0
   ])
   AC_SUBST([WINDOWS_64_BIT_ST_SIZE])
-  if test $WINDOWS_64_BIT_ST_SIZE = 1; then
-    AC_DEFINE([_GL_WINDOWS_64_BIT_ST_SIZE], [1],
-      [Define to 1 if Gnulib overrides 'struct stat' on Windows so that
-       struct stat.st_size becomes 64-bit.])
-  fi
 
   dnl Define types that are supposed to be defined in <sys/types.h> or
   dnl <sys/stat.h>.
@@ -72,6 +75,7 @@ AC_DEFUN([gl_SYS_STAT_H_DEFAULTS],
   GNULIB_MKNODAT=0;     AC_SUBST([GNULIB_MKNODAT])
   GNULIB_STAT=0;        AC_SUBST([GNULIB_STAT])
   GNULIB_UTIMENSAT=0;   AC_SUBST([GNULIB_UTIMENSAT])
+  GNULIB_OVERRIDES_STRUCT_STAT=0; AC_SUBST([GNULIB_OVERRIDES_STRUCT_STAT])
   dnl Assume proper GNU behavior unless another module says otherwise.
   HAVE_FCHMODAT=1;      AC_SUBST([HAVE_FCHMODAT])
   HAVE_FSTATAT=1;       AC_SUBST([HAVE_FSTATAT])
diff --git a/m4/sys_time_h.m4 b/m4/sys_time_h.m4
index e622dbe9a24..1c8c3cfcc32 100644
--- a/m4/sys_time_h.m4
+++ b/m4/sys_time_h.m4
@@ -1,5 +1,5 @@
 # Configure a replacement for <sys/time.h>.
-# serial 8
+# serial 9
 
 # Copyright (C) 2007, 2009-2017 Free Software Foundation, Inc.
 # This file is free software; the Free Software Foundation
@@ -105,7 +105,6 @@ AC_DEFUN([gl_HEADER_SYS_TIME_H_DEFAULTS],
   HAVE_GETTIMEOFDAY=1;       AC_SUBST([HAVE_GETTIMEOFDAY])
   HAVE_STRUCT_TIMEVAL=1;     AC_SUBST([HAVE_STRUCT_TIMEVAL])
   HAVE_SYS_TIME_H=1;         AC_SUBST([HAVE_SYS_TIME_H])
-  HAVE_TIMEZONE_T=0;         AC_SUBST([HAVE_TIMEZONE_T])
   REPLACE_GETTIMEOFDAY=0;    AC_SUBST([REPLACE_GETTIMEOFDAY])
   REPLACE_STRUCT_TIMEVAL=0;  AC_SUBST([REPLACE_STRUCT_TIMEVAL])
 ])
diff --git a/m4/time_h.m4 b/m4/time_h.m4
index f52b60192e8..28e22092e14 100644
--- a/m4/time_h.m4
+++ b/m4/time_h.m4
@@ -2,7 +2,7 @@
 
 # Copyright (C) 2000-2001, 2003-2007, 2009-2017 Free Software Foundation, Inc.
 
-# serial 10
+# serial 11
 
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -120,6 +120,8 @@ AC_DEFUN([gl_HEADER_TIME_H_DEFAULTS],
   HAVE_STRPTIME=1;                       AC_SUBST([HAVE_STRPTIME])
   HAVE_TIMEGM=1;                         AC_SUBST([HAVE_TIMEGM])
   HAVE_TZSET=1;                          AC_SUBST([HAVE_TZSET])
+  dnl Even GNU libc does not have timezone_t yet.
+  HAVE_TIMEZONE_T=0;                     AC_SUBST([HAVE_TIMEZONE_T])
   dnl If another module says to replace or to not replace, do that.
   dnl Otherwise, replace only if someone compiles with -DGNULIB_PORTCHECK;
   dnl this lets maintainers check for portability.
diff --git a/m4/time_rz.m4 b/m4/time_rz.m4
index 079e933b4e6..3991118b61c 100644
--- a/m4/time_rz.m4
+++ b/m4/time_rz.m4
@@ -10,7 +10,7 @@ dnl Written by Paul Eggert.
 AC_DEFUN([gl_TIME_RZ],
 [
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
-  AC_REQUIRE([gl_HEADER_SYS_TIME_H_DEFAULTS])
+  AC_REQUIRE([gl_HEADER_TIME_H_DEFAULTS])
   AC_REQUIRE([AC_STRUCT_TIMEZONE])
 
   AC_CHECK_TYPES([timezone_t], [], [], [[#include <time.h>]])
diff --git a/m4/unistd_h.m4 b/m4/unistd_h.m4
index 25aef19ec9d..cc44677d9eb 100644
--- a/m4/unistd_h.m4
+++ b/m4/unistd_h.m4
@@ -1,4 +1,4 @@
-# unistd_h.m4 serial 69
+# unistd_h.m4 serial 70
 dnl Copyright (C) 2006-2017 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -46,8 +46,8 @@ AC_DEFUN([gl_UNISTD_H],
     gethostname getlogin getlogin_r getpagesize
     getusershell setusershell endusershell
     group_member isatty lchown link linkat lseek pipe pipe2 pread pwrite
-    readlink readlinkat rmdir sethostname sleep symlink symlinkat ttyname_r
-    unlink unlinkat usleep])
+    readlink readlinkat rmdir sethostname sleep symlink symlinkat
+    truncate ttyname_r unlink unlinkat usleep])
 ])
 
 AC_DEFUN([gl_UNISTD_MODULE_INDICATOR],
@@ -102,6 +102,7 @@ AC_DEFUN([gl_UNISTD_H_DEFAULTS],
   GNULIB_SLEEP=0;                AC_SUBST([GNULIB_SLEEP])
   GNULIB_SYMLINK=0;              AC_SUBST([GNULIB_SYMLINK])
   GNULIB_SYMLINKAT=0;            AC_SUBST([GNULIB_SYMLINKAT])
+  GNULIB_TRUNCATE=0;             AC_SUBST([GNULIB_TRUNCATE])
   GNULIB_TTYNAME_R=0;            AC_SUBST([GNULIB_TTYNAME_R])
   GNULIB_UNISTD_H_NONBLOCKING=0; AC_SUBST([GNULIB_UNISTD_H_NONBLOCKING])
   GNULIB_UNISTD_H_SIGPIPE=0;     AC_SUBST([GNULIB_UNISTD_H_SIGPIPE])
@@ -139,6 +140,7 @@ AC_DEFUN([gl_UNISTD_H_DEFAULTS],
   HAVE_SLEEP=1;           AC_SUBST([HAVE_SLEEP])
   HAVE_SYMLINK=1;         AC_SUBST([HAVE_SYMLINK])
   HAVE_SYMLINKAT=1;       AC_SUBST([HAVE_SYMLINKAT])
+  HAVE_TRUNCATE=1;        AC_SUBST([HAVE_TRUNCATE])
   HAVE_UNLINKAT=1;        AC_SUBST([HAVE_UNLINKAT])
   HAVE_USLEEP=1;          AC_SUBST([HAVE_USLEEP])
   HAVE_DECL_ENVIRON=1;    AC_SUBST([HAVE_DECL_ENVIRON])
@@ -179,6 +181,7 @@ AC_DEFUN([gl_UNISTD_H_DEFAULTS],
   REPLACE_SLEEP=0;        AC_SUBST([REPLACE_SLEEP])
   REPLACE_SYMLINK=0;      AC_SUBST([REPLACE_SYMLINK])
   REPLACE_SYMLINKAT=0;    AC_SUBST([REPLACE_SYMLINKAT])
+  REPLACE_TRUNCATE=0;     AC_SUBST([REPLACE_TRUNCATE])
   REPLACE_TTYNAME_R=0;    AC_SUBST([REPLACE_TTYNAME_R])
   REPLACE_UNLINK=0;       AC_SUBST([REPLACE_UNLINK])
   REPLACE_UNLINKAT=0;     AC_SUBST([REPLACE_UNLINKAT])