Merge from gnulib

This incorporates:
2017-05-01 New module 'localtime-buffer'
2017-04-30 utimens: Add support for native Windows
* admin/merge-gnulib (AVOIDED_MODULES): Add tzset.
* configure.ac (tzset): No need for Emacs itself to check now.
* lib/gettimeofday.c, lib/time.in.h, lib/time_rz.c, lib/utimens.c:
* m4/gettimeofday.m4, m4/time_h.m4, m4/time_rz.m4: Copy from gnulib.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* lib/localtime-buffer.c, lib/localtime-buffer.h:
* m4/localtime-buffer.m4: New files, copied from gnulib.
* src/editfns.c (init_editfns): Assume tzset is callable.

15 files changed, 261 insertions, 101 deletions

diff --git a/admin/merge-gnulib b/admin/merge-gnulib
index c2ab3571fee..45e4a788a35 100755
--- a/admin/merge-gnulib
+++ b/admin/merge-gnulib
@@ -49,7 +49,7 @@ AVOIDED_MODULES='
   malloc-posix msvc-inval msvc-nothrow
   open openat-die opendir raise
   save-cwd select setenv sigprocmask stat stdarg stdbool
-  threadlib unsetenv utime-h
+  threadlib tzset unsetenv utime utime-h
 '
 
 GNULIB_TOOL_FLAGS='
diff --git a/configure.ac b/configure.ac
index c545663e9ed..45cfdfcb4b9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -4195,7 +4195,7 @@ AC_CHECK_HEADERS(valgrind/valgrind.h)
 
 AC_CHECK_MEMBERS([struct unipair.unicode], [], [], [[#include <linux/kd.h>]])
 
-AC_CHECK_FUNCS_ONCE([sbrk tzset])
+AC_CHECK_FUNCS_ONCE([sbrk])
 
 ok_so_far=yes
 AC_CHECK_FUNC(socket, , ok_so_far=no)
diff --git a/lib/gettimeofday.c b/lib/gettimeofday.c
index 86f1a8c1d28..1039f77d182 100644
--- a/lib/gettimeofday.c
+++ b/lib/gettimeofday.c
@@ -29,72 +29,7 @@
 # include <windows.h>
 #endif
 
-#if GETTIMEOFDAY_CLOBBERS_LOCALTIME || TZSET_CLOBBERS_LOCALTIME
-
-/* Work around the bug in some systems whereby gettimeofday clobbers
-   the static buffer that localtime uses for its return value.  The
-   gettimeofday function from Mac OS X 10.0.4 (i.e., Darwin 1.3.7) has
-   this problem.  The tzset replacement is necessary for at least
-   Solaris 2.5, 2.5.1, and 2.6.  */
-
-static struct tm tm_zero_buffer;
-static struct tm *localtime_buffer_addr = &tm_zero_buffer;
-
-# undef localtime
-extern struct tm *localtime (time_t const *);
-
-# undef gmtime
-extern struct tm *gmtime (time_t const *);
-
-/* This is a wrapper for localtime.  It is used only on systems for which
-   gettimeofday clobbers the static buffer used for localtime's result.
-
-   On the first call, record the address of the static buffer that
-   localtime uses for its result.  */
-
-struct tm *
-rpl_localtime (time_t const *timep)
-{
-  struct tm *tm = localtime (timep);
-
-  if (localtime_buffer_addr == &tm_zero_buffer)
-    localtime_buffer_addr = tm;
-
-  return tm;
-}
-
-/* Same as above, since gmtime and localtime use the same buffer.  */
-struct tm *
-rpl_gmtime (time_t const *timep)
-{
-  struct tm *tm = gmtime (timep);
-
-  if (localtime_buffer_addr == &tm_zero_buffer)
-    localtime_buffer_addr = tm;
-
-  return tm;
-}
-
-#endif /* GETTIMEOFDAY_CLOBBERS_LOCALTIME || TZSET_CLOBBERS_LOCALTIME */
-
-#if TZSET_CLOBBERS_LOCALTIME
-
-# undef tzset
-extern void tzset (void);
-
-/* This is a wrapper for tzset, for systems on which tzset may clobber
-   the static buffer used for localtime's result.  */
-void
-rpl_tzset (void)
-{
-  /* Save and restore the contents of the buffer used for localtime's
-     result around the call to tzset.  */
-  struct tm save = *localtime_buffer_addr;
-  tzset ();
-  *localtime_buffer_addr = save;
-}
-
-#endif
+#include "localtime-buffer.h"
 
 #ifdef WINDOWS_NATIVE
 
@@ -119,7 +54,11 @@ initialize (void)
 
 /* This is a wrapper for gettimeofday.  It is used only on systems
    that lack this function, or whose implementation of this function
-   causes problems.  */
+   causes problems.
+   Work around the bug in some systems whereby gettimeofday clobbers
+   the static buffer that localtime uses for its return value.  The
+   gettimeofday function from Mac OS X 10.0.4 (i.e., Darwin 1.3.7) has
+   this problem.  */
 
 int
 gettimeofday (struct timeval *restrict tv, void *restrict tz)
diff --git a/lib/gnulib.mk.in b/lib/gnulib.mk.in
index 59cdbdb847a..51ae1891244 100644
--- a/lib/gnulib.mk.in
+++ b/lib/gnulib.mk.in
@@ -21,7 +21,7 @@
 # the same distribution terms as the rest of that program.
 #
 # Generated by gnulib-tool.
-# Reproduce by: gnulib-tool --import --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --avoid=close --avoid=dup --avoid=fchdir --avoid=fstat --avoid=malloc-posix --avoid=msvc-inval --avoid=msvc-nothrow --avoid=open --avoid=openat-die --avoid=opendir --avoid=raise --avoid=save-cwd --avoid=select --avoid=setenv --avoid=sigprocmask --avoid=stat --avoid=stdarg --avoid=stdbool --avoid=threadlib --avoid=unsetenv --avoid=utime-h --gnu-make --makefile-name=gnulib.mk.in --conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca-opt binary-io byteswap c-ctype c-strcase careadlinkat close-stream count-leading-zeros count-one-bits count-trailing-zeros crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512 dtoastr dtotimespec dup2 environ execinfo faccessat fcntl fcntl-h fdatasync fdopendir filemode filevercmp flexmember fstatat fsync getloadavg getopt-gnu gettime gettimeofday gitlog-to-changelog ignore-value intprops largefile lstat manywarnings memrchr mkostemp mktime pipe2 pselect pthread_sigmask putenv qcopy-acl readlink readlinkat sig2str socklen stat-time std-gnu11 stdalign stddef stdio stpcpy strftime strtoimax strtoumax symlink sys_stat sys_time time time_r time_rz timegm timer-time timespec-add timespec-sub update-copyright utimens vla warnings
+# Reproduce by: gnulib-tool --import --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --avoid=close --avoid=dup --avoid=fchdir --avoid=fstat --avoid=malloc-posix --avoid=msvc-inval --avoid=msvc-nothrow --avoid=open --avoid=openat-die --avoid=opendir --avoid=raise --avoid=save-cwd --avoid=select --avoid=setenv --avoid=sigprocmask --avoid=stat --avoid=stdarg --avoid=stdbool --avoid=threadlib --avoid=tzset --avoid=unsetenv --avoid=utime --avoid=utime-h --gnu-make --makefile-name=gnulib.mk.in --conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca-opt binary-io byteswap c-ctype c-strcase careadlinkat close-stream count-leading-zeros count-one-bits count-trailing-zeros crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512 dtoastr dtotimespec dup2 environ execinfo faccessat fcntl fcntl-h fdatasync fdopendir filemode filevercmp flexmember fstatat fsync getloadavg getopt-gnu gettime gettimeofday gitlog-to-changelog ignore-value intprops largefile lstat manywarnings memrchr mkostemp mktime pipe2 pselect pthread_sigmask putenv qcopy-acl readlink readlinkat sig2str socklen stat-time std-gnu11 stdalign stddef stdio stpcpy strftime strtoimax strtoumax symlink sys_stat sys_time time time_r time_rz timegm timer-time timespec-add timespec-sub update-copyright utimens vla warnings
 
 
 MOSTLYCLEANFILES += core *.stackdump
@@ -307,6 +307,7 @@ GNULIB_TIME_R = @GNULIB_TIME_R@
 GNULIB_TIME_RZ = @GNULIB_TIME_RZ@
 GNULIB_TMPFILE = @GNULIB_TMPFILE@
 GNULIB_TTYNAME_R = @GNULIB_TTYNAME_R@
+GNULIB_TZSET = @GNULIB_TZSET@
 GNULIB_UNISTD_H_NONBLOCKING = @GNULIB_UNISTD_H_NONBLOCKING@
 GNULIB_UNISTD_H_SIGPIPE = @GNULIB_UNISTD_H_SIGPIPE@
 GNULIB_UNLINK = @GNULIB_UNLINK@
@@ -504,6 +505,7 @@ HAVE_SYS_TYPES_H = @HAVE_SYS_TYPES_H@
 HAVE_TIMEGM = @HAVE_TIMEGM@
 HAVE_TIMEZONE_T = @HAVE_TIMEZONE_T@
 HAVE_TYPE_VOLATILE_SIG_ATOMIC_T = @HAVE_TYPE_VOLATILE_SIG_ATOMIC_T@
+HAVE_TZSET = @HAVE_TZSET@
 HAVE_UNISTD_H = @HAVE_UNISTD_H@
 HAVE_UNLINKAT = @HAVE_UNLINKAT@
 HAVE_UNLOCKPT = @HAVE_UNLOCKPT@
@@ -780,6 +782,7 @@ REPLACE_SYMLINKAT = @REPLACE_SYMLINKAT@
 REPLACE_TIMEGM = @REPLACE_TIMEGM@
 REPLACE_TMPFILE = @REPLACE_TMPFILE@
 REPLACE_TTYNAME_R = @REPLACE_TTYNAME_R@
+REPLACE_TZSET = @REPLACE_TZSET@
 REPLACE_UNLINK = @REPLACE_UNLINK@
 REPLACE_UNLINKAT = @REPLACE_UNLINKAT@
 REPLACE_UNSETENV = @REPLACE_UNSETENV@
@@ -879,6 +882,7 @@ gamedir = @gamedir@
 gamegroup = @gamegroup@
 gameuser = @gameuser@
 gl_GNULIB_ENABLED_03e0aaad4cb89ca757653bd367a6ccb7 = @gl_GNULIB_ENABLED_03e0aaad4cb89ca757653bd367a6ccb7@
+gl_GNULIB_ENABLED_2049e887c7e5308faad27b3f894bb8c9 = @gl_GNULIB_ENABLED_2049e887c7e5308faad27b3f894bb8c9@
 gl_GNULIB_ENABLED_260941c0e5dc67ec9e87d1fb321c300b = @gl_GNULIB_ENABLED_260941c0e5dc67ec9e87d1fb321c300b@
 gl_GNULIB_ENABLED_5264294aa0a5557541b53c8c741f7f31 = @gl_GNULIB_ENABLED_5264294aa0a5557541b53c8c741f7f31@
 gl_GNULIB_ENABLED_6099e9737f757db36c47fa9d9f02e88c = @gl_GNULIB_ENABLED_6099e9737f757db36c47fa9d9f02e88c@
@@ -1700,6 +1704,19 @@ EXTRA_DIST += limits.in.h
 endif
 ## end   gnulib module limits-h
 
+## begin gnulib module localtime-buffer
+ifeq (,$(OMIT_GNULIB_MODULE_localtime-buffer))
+
+ifneq (,$(gl_GNULIB_ENABLED_2049e887c7e5308faad27b3f894bb8c9))
+
+endif
+EXTRA_DIST += localtime-buffer.c localtime-buffer.h
+
+EXTRA_libgnu_a_SOURCES += localtime-buffer.c
+
+endif
+## end   gnulib module localtime-buffer
+
 ## begin gnulib module lstat
 ifeq (,$(OMIT_GNULIB_MODULE_lstat))
 
@@ -2707,7 +2724,6 @@ time.h: time.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H) $(
               -e 's|@''PRAGMA_COLUMNS''@|@PRAGMA_COLUMNS@|g' \
               -e 's|@''NEXT_TIME_H''@|$(NEXT_TIME_H)|g' \
               -e 's/@''GNULIB_CTIME''@/$(GNULIB_CTIME)/g' \
-              -e 's/@''GNULIB_GETTIMEOFDAY''@/$(GNULIB_GETTIMEOFDAY)/g' \
               -e 's/@''GNULIB_LOCALTIME''@/$(GNULIB_LOCALTIME)/g' \
               -e 's/@''GNULIB_MKTIME''@/$(GNULIB_MKTIME)/g' \
               -e 's/@''GNULIB_NANOSLEEP''@/$(GNULIB_NANOSLEEP)/g' \
@@ -2716,11 +2732,13 @@ time.h: time.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H) $(
               -e 's/@''GNULIB_TIMEGM''@/$(GNULIB_TIMEGM)/g' \
               -e 's/@''GNULIB_TIME_R''@/$(GNULIB_TIME_R)/g' \
               -e 's/@''GNULIB_TIME_RZ''@/$(GNULIB_TIME_RZ)/g' \
+              -e 's/@''GNULIB_TZSET''@/$(GNULIB_TZSET)/g' \
               -e 's|@''HAVE_DECL_LOCALTIME_R''@|$(HAVE_DECL_LOCALTIME_R)|g' \
               -e 's|@''HAVE_NANOSLEEP''@|$(HAVE_NANOSLEEP)|g' \
               -e 's|@''HAVE_STRPTIME''@|$(HAVE_STRPTIME)|g' \
               -e 's|@''HAVE_TIMEGM''@|$(HAVE_TIMEGM)|g' \
               -e 's|@''HAVE_TIMEZONE_T''@|$(HAVE_TIMEZONE_T)|g' \
+              -e 's|@''HAVE_TZSET''@|$(HAVE_TZSET)|g' \
               -e 's|@''REPLACE_CTIME''@|$(REPLACE_CTIME)|g' \
               -e 's|@''REPLACE_GMTIME''@|$(REPLACE_GMTIME)|g' \
               -e 's|@''REPLACE_LOCALTIME''@|$(REPLACE_LOCALTIME)|g' \
@@ -2729,6 +2747,7 @@ time.h: time.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H) $(
               -e 's|@''REPLACE_NANOSLEEP''@|$(REPLACE_NANOSLEEP)|g' \
               -e 's|@''REPLACE_STRFTIME''@|$(REPLACE_STRFTIME)|g' \
               -e 's|@''REPLACE_TIMEGM''@|$(REPLACE_TIMEGM)|g' \
+              -e 's|@''REPLACE_TZSET''@|$(REPLACE_TZSET)|g' \
               -e 's|@''PTHREAD_H_DEFINES_STRUCT_TIMESPEC''@|$(PTHREAD_H_DEFINES_STRUCT_TIMESPEC)|g' \
               -e 's|@''SYS_TIME_H_DEFINES_STRUCT_TIMESPEC''@|$(SYS_TIME_H_DEFINES_STRUCT_TIMESPEC)|g' \
               -e 's|@''TIME_H_DEFINES_STRUCT_TIMESPEC''@|$(TIME_H_DEFINES_STRUCT_TIMESPEC)|g' \
diff --git a/lib/localtime-buffer.c b/lib/localtime-buffer.c
new file mode 100644
index 00000000000..f84ad3e8238
--- /dev/null
+++ b/lib/localtime-buffer.c
@@ -0,0 +1,58 @@
+/* Provide access to the last buffer returned by localtime() or gmtime().
+
+   Copyright (C) 2001-2003, 2005-2007, 2009-2017 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
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, see <http://www.gnu.org/licenses/>.  */
+
+/* written by Jim Meyering */
+
+#include <config.h>
+
+/* Specification.  */
+#include "localtime-buffer.h"
+
+#if GETTIMEOFDAY_CLOBBERS_LOCALTIME || TZSET_CLOBBERS_LOCALTIME
+
+static struct tm tm_zero_buffer;
+struct tm *localtime_buffer_addr = &tm_zero_buffer;
+
+/* This is a wrapper for localtime.
+
+   On the first call, record the address of the static buffer that
+   localtime uses for its result.  */
+
+struct tm *
+rpl_localtime (time_t const *timep)
+{
+  struct tm *tm = localtime (timep);
+
+  if (localtime_buffer_addr == &tm_zero_buffer)
+    localtime_buffer_addr = tm;
+
+  return tm;
+}
+
+/* Same as above, since gmtime and localtime use the same buffer.  */
+struct tm *
+rpl_gmtime (time_t const *timep)
+{
+  struct tm *tm = gmtime (timep);
+
+  if (localtime_buffer_addr == &tm_zero_buffer)
+    localtime_buffer_addr = tm;
+
+  return tm;
+}
+
+#endif
diff --git a/lib/localtime-buffer.h b/lib/localtime-buffer.h
new file mode 100644
index 00000000000..483a579bda4
--- /dev/null
+++ b/lib/localtime-buffer.h
@@ -0,0 +1,27 @@
+/* Provide access to the last buffer returned by localtime() or gmtime().
+
+   Copyright (C) 2001-2003, 2005-2007, 2009-2017 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
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, see <http://www.gnu.org/licenses/>.  */
+
+/* written by Jim Meyering */
+
+#include <time.h>
+
+#if GETTIMEOFDAY_CLOBBERS_LOCALTIME || TZSET_CLOBBERS_LOCALTIME
+
+/* The address of the last buffer returned by localtime() or gmtime().  */
+extern struct tm *localtime_buffer_addr;
+
+#endif
diff --git a/lib/time.in.h b/lib/time.in.h
index d2a0302f464..f0c7ef86667 100644
--- a/lib/time.in.h
+++ b/lib/time.in.h
@@ -120,6 +120,24 @@ _GL_CXXALIAS_SYS (nanosleep, int,
 _GL_CXXALIASWARN (nanosleep);
 # endif
 
+/* Initialize time conversion information.  */
+# if @GNULIB_TZSET@
+#  if @REPLACE_TZSET@
+#   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#    undef tzset
+#    define tzset rpl_tzset
+#   endif
+_GL_FUNCDECL_RPL (tzset, void, (void));
+_GL_CXXALIAS_RPL (tzset, void, (void));
+#  else
+#   if ! @HAVE_TZSET@
+_GL_FUNCDECL_SYS (tzset, void, (void));
+#   endif
+_GL_CXXALIAS_SYS (tzset, void, (void));
+#  endif
+_GL_CXXALIASWARN (tzset);
+# endif
+
 /* Return the 'time_t' representation of TP and normalize TP.  */
 # if @GNULIB_MKTIME@
 #  if @REPLACE_MKTIME@
@@ -187,7 +205,7 @@ _GL_CXXALIASWARN (gmtime_r);
 /* Convert TIMER to RESULT, assuming local time and UTC respectively.  See
    <http://www.opengroup.org/susv3xsh/localtime.html> and
    <http://www.opengroup.org/susv3xsh/gmtime.html>.  */
-# if @GNULIB_LOCALTIME@ || @GNULIB_GETTIMEOFDAY@
+# if @GNULIB_LOCALTIME@ || @REPLACE_LOCALTIME@
 #  if @REPLACE_LOCALTIME@
 #   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 #    undef localtime
@@ -202,7 +220,7 @@ _GL_CXXALIAS_SYS (localtime, struct tm *, (time_t const *__timer));
 _GL_CXXALIASWARN (localtime);
 # endif
 
-# if @GNULIB_GETTIMEOFDAY@
+# if 0 || @REPLACE_GMTIME@
 #  if @REPLACE_GMTIME@
 #   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 #    undef gmtime
diff --git a/lib/time_rz.c b/lib/time_rz.c
index c41a8ef47ac..17bc11c20e9 100644
--- a/lib/time_rz.c
+++ b/lib/time_rz.c
@@ -40,10 +40,6 @@
 # define SIZE_MAX ((size_t) -1)
 #endif
 
-#if !HAVE_TZSET
-static void tzset (void) { }
-#endif
-
 /* The approximate size to use for small allocation requests.  This is
    the largest "small" request for the GNU C library malloc.  */
 enum { DEFAULT_MXFAST = 64 * sizeof (size_t) / 4 };
diff --git a/lib/utimens.c b/lib/utimens.c
index 3b451193350..0b3b8e2f3af 100644
--- a/lib/utimens.c
+++ b/lib/utimens.c
@@ -35,6 +35,12 @@
 #include "stat-time.h"
 #include "timespec.h"
 
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+# include "msvc-nothrow.h"
+#endif
+
 /* Avoid recursion with rpl_futimens or rpl_utimensat.  */
 #undef futimens
 #undef utimensat
@@ -271,6 +277,82 @@ fdutimens (int fd, char const *file, struct timespec const timespec[2])
   lutimensat_works_really = -1;
 #endif /* HAVE_UTIMENSAT || HAVE_FUTIMENS */
 
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+  /* On native Windows, use SetFileTime(). See
+     <https://msdn.microsoft.com/en-us/library/ms724933.aspx>
+     <https://msdn.microsoft.com/en-us/library/ms724284.aspx>  */
+  if (0 <= fd)
+    {
+      HANDLE handle;
+      FILETIME current_time;
+      FILETIME last_access_time;
+      FILETIME last_write_time;
+
+      handle = (HANDLE) _get_osfhandle (fd);
+      if (handle == INVALID_HANDLE_VALUE)
+        {
+          errno = EBADF;
+          return -1;
+        }
+
+      if (ts == NULL || ts[0].tv_nsec == UTIME_NOW || ts[1].tv_nsec == UTIME_NOW)
+        {
+          /* GetSystemTimeAsFileTime
+             <https://msdn.microsoft.com/en-us/library/ms724397.aspx>.
+             It would be overkill to use
+             GetSystemTimePreciseAsFileTime
+             <https://msdn.microsoft.com/en-us/library/hh706895.aspx>.  */
+          GetSystemTimeAsFileTime (&current_time);
+        }
+
+      if (ts == NULL || ts[0].tv_nsec == UTIME_NOW)
+        {
+          last_access_time = current_time;
+        }
+      else if (ts[0].tv_nsec == UTIME_OMIT)
+        {
+          last_access_time.dwLowDateTime = 0;
+          last_access_time.dwHighDateTime = 0;
+        }
+      else
+        {
+          ULONGLONG time_since_16010101 =
+            (ULONGLONG) ts[0].tv_sec * 10000000 + ts[0].tv_nsec / 100 + 116444736000000000LL;
+          last_access_time.dwLowDateTime = (DWORD) time_since_16010101;
+          last_access_time.dwHighDateTime = time_since_16010101 >> 32;
+        }
+
+      if (ts == NULL || ts[1].tv_nsec == UTIME_NOW)
+        {
+          last_write_time = current_time;
+        }
+      else if (ts[1].tv_nsec == UTIME_OMIT)
+        {
+          last_write_time.dwLowDateTime = 0;
+          last_write_time.dwHighDateTime = 0;
+        }
+      else
+        {
+          ULONGLONG time_since_16010101 =
+            (ULONGLONG) ts[1].tv_sec * 10000000 + ts[1].tv_nsec / 100 + 116444736000000000LL;
+          last_write_time.dwLowDateTime = (DWORD) time_since_16010101;
+          last_write_time.dwHighDateTime = time_since_16010101 >> 32;
+        }
+
+      if (SetFileTime (handle, NULL, &last_access_time, &last_write_time))
+        return 0;
+      else
+        {
+          #if 0
+          DWORD sft_error = GetLastError ();
+          fprintf (stderr, "utime SetFileTime error 0x%x\n", (unsigned int) sft_error);
+          #endif
+          errno = EINVAL;
+          return -1;
+        }
+    }
+#endif
+
   /* The platform lacks an interface to set file timestamps with
      nanosecond resolution, so do the best we can, discarding any
      fractional part of the timestamp.  */
diff --git a/m4/gettimeofday.m4 b/m4/gettimeofday.m4
index 742b6c9e10e..34adc64778f 100644
--- a/m4/gettimeofday.m4
+++ b/m4/gettimeofday.m4
@@ -54,19 +54,6 @@ int gettimeofday (struct timeval *restrict, struct timezone *restrict);
     if test $REPLACE_STRUCT_TIMEVAL = 1; then
       REPLACE_GETTIMEOFDAY=1
     fi
-    m4_ifdef([gl_FUNC_TZSET_CLOBBER], [
-      gl_FUNC_TZSET_CLOBBER
-      case "$gl_cv_func_tzset_clobber" in
-        *yes)
-          REPLACE_GETTIMEOFDAY=1
-          gl_GETTIMEOFDAY_REPLACE_LOCALTIME
-          AC_DEFINE([tzset], [rpl_tzset],
-            [Define to rpl_tzset if the wrapper function should be used.])
-          AC_DEFINE([TZSET_CLOBBERS_LOCALTIME], [1],
-            [Define if tzset clobbers localtime's static buffer.])
-          ;;
-      esac
-    ])
   fi
   AC_DEFINE_UNQUOTED([GETTIMEOFDAY_TIMEZONE], [$gl_gettimeofday_timezone],
     [Define this to 'void' or 'struct timezone' to match the system's
@@ -85,6 +72,7 @@ AC_DEFUN([gl_FUNC_GETTIMEOFDAY_CLOBBER],
 [
  AC_REQUIRE([gl_HEADER_SYS_TIME_H])
  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_REQUIRE([gl_LOCALTIME_BUFFER_DEFAULTS])
 
  AC_CACHE_CHECK([whether gettimeofday clobbers localtime buffer],
   [gl_cv_func_gettimeofday_clobber],
@@ -119,17 +107,12 @@ AC_DEFUN([gl_FUNC_GETTIMEOFDAY_CLOBBER],
  case "$gl_cv_func_gettimeofday_clobber" in
    *yes)
      REPLACE_GETTIMEOFDAY=1
-     gl_GETTIMEOFDAY_REPLACE_LOCALTIME
      AC_DEFINE([GETTIMEOFDAY_CLOBBERS_LOCALTIME], [1],
        [Define if gettimeofday clobbers the localtime buffer.])
+     gl_LOCALTIME_BUFFER_NEEDED
      ;;
  esac
 ])
 
-AC_DEFUN([gl_GETTIMEOFDAY_REPLACE_LOCALTIME], [
-  REPLACE_GMTIME=1
-  REPLACE_LOCALTIME=1
-])
-
 # Prerequisites of lib/gettimeofday.c.
 AC_DEFUN([gl_PREREQ_GETTIMEOFDAY], [:])
diff --git a/m4/gnulib-comp.m4 b/m4/gnulib-comp.m4
index 136762430e0..74b197c8633 100644
--- a/m4/gnulib-comp.m4
+++ b/m4/gnulib-comp.m4
@@ -101,6 +101,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module largefile:
   AC_REQUIRE([AC_SYS_LARGEFILE])
   # Code from module limits-h:
+  # Code from module localtime-buffer:
   # Code from module lstat:
   # Code from module manywarnings:
   # Code from module memrchr:
@@ -413,6 +414,7 @@ AC_DEFUN([gl_INIT],
   gl_gnulib_enabled_getgroups=false
   gl_gnulib_enabled_be453cec5eecf5731a274f2de7f2db36=false
   gl_gnulib_enabled_a9786850e999ae65a836a6041e8e5ed1=false
+  gl_gnulib_enabled_2049e887c7e5308faad27b3f894bb8c9=false
   gl_gnulib_enabled_5264294aa0a5557541b53c8c741f7f31=false
   gl_gnulib_enabled_03e0aaad4cb89ca757653bd367a6ccb7=false
   gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c=false
@@ -512,6 +514,14 @@ AC_DEFUN([gl_INIT],
       fi
     fi
   }
+  func_gl_gnulib_m4code_2049e887c7e5308faad27b3f894bb8c9 ()
+  {
+    if ! $gl_gnulib_enabled_2049e887c7e5308faad27b3f894bb8c9; then
+      AC_REQUIRE([gl_LOCALTIME_BUFFER_DEFAULTS])
+      AC_LIBOBJ([localtime-buffer])
+      gl_gnulib_enabled_2049e887c7e5308faad27b3f894bb8c9=true
+    fi
+  }
   func_gl_gnulib_m4code_5264294aa0a5557541b53c8c741f7f31 ()
   {
     if ! $gl_gnulib_enabled_5264294aa0a5557541b53c8c741f7f31; then
@@ -618,6 +628,9 @@ AC_DEFUN([gl_INIT],
   if test $REPLACE_GETOPT = 1; then
     func_gl_gnulib_m4code_be453cec5eecf5731a274f2de7f2db36
   fi
+  if test $NEED_LOCALTIME_BUFFER = 1; then
+    func_gl_gnulib_m4code_2049e887c7e5308faad27b3f894bb8c9
+  fi
   if test $REPLACE_LSTAT = 1; then
     func_gl_gnulib_m4code_dosname
   fi
@@ -651,6 +664,7 @@ AC_DEFUN([gl_INIT],
   AM_CONDITIONAL([gl_GNULIB_ENABLED_getgroups], [$gl_gnulib_enabled_getgroups])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_be453cec5eecf5731a274f2de7f2db36], [$gl_gnulib_enabled_be453cec5eecf5731a274f2de7f2db36])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_a9786850e999ae65a836a6041e8e5ed1], [$gl_gnulib_enabled_a9786850e999ae65a836a6041e8e5ed1])
+  AM_CONDITIONAL([gl_GNULIB_ENABLED_2049e887c7e5308faad27b3f894bb8c9], [$gl_gnulib_enabled_2049e887c7e5308faad27b3f894bb8c9])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_5264294aa0a5557541b53c8c741f7f31], [$gl_gnulib_enabled_5264294aa0a5557541b53c8c741f7f31])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_03e0aaad4cb89ca757653bd367a6ccb7], [$gl_gnulib_enabled_03e0aaad4cb89ca757653bd367a6ccb7])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_6099e9737f757db36c47fa9d9f02e88c], [$gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c])
@@ -880,6 +894,8 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/intprops.h
   lib/inttypes.in.h
   lib/limits.in.h
+  lib/localtime-buffer.c
+  lib/localtime-buffer.h
   lib/lstat.c
   lib/md5.c
   lib/md5.h
@@ -997,6 +1013,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/inttypes.m4
   m4/largefile.m4
   m4/limits-h.m4
+  m4/localtime-buffer.m4
   m4/longlong.m4
   m4/lstat.m4
   m4/manywarnings.m4
diff --git a/m4/localtime-buffer.m4 b/m4/localtime-buffer.m4
new file mode 100644
index 00000000000..3965b5d9f2b
--- /dev/null
+++ b/m4/localtime-buffer.m4
@@ -0,0 +1,21 @@
+# localtime-buffer.m4 serial 1
+dnl Copyright (C) 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,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_LOCALTIME_BUFFER_DEFAULTS],
+[
+  NEED_LOCALTIME_BUFFER=0
+])
+
+dnl Macro invoked from other modules, to signal that the compilation of
+dnl module 'localtime-buffer' is needed.
+AC_DEFUN([gl_LOCALTIME_BUFFER_NEEDED],
+[
+  AC_REQUIRE([gl_LOCALTIME_BUFFER_DEFAULTS])
+  AC_REQUIRE([gl_HEADER_TIME_H_DEFAULTS])
+  NEED_LOCALTIME_BUFFER=1
+  REPLACE_GMTIME=1
+  REPLACE_LOCALTIME=1
+])
diff --git a/m4/time_h.m4 b/m4/time_h.m4
index e0f663ec711..f52b60192e8 100644
--- a/m4/time_h.m4
+++ b/m4/time_h.m4
@@ -113,11 +113,13 @@ AC_DEFUN([gl_HEADER_TIME_H_DEFAULTS],
   GNULIB_TIMEGM=0;                       AC_SUBST([GNULIB_TIMEGM])
   GNULIB_TIME_R=0;                       AC_SUBST([GNULIB_TIME_R])
   GNULIB_TIME_RZ=0;                      AC_SUBST([GNULIB_TIME_RZ])
+  GNULIB_TZSET=0;                        AC_SUBST([GNULIB_TZSET])
   dnl Assume proper GNU behavior unless another module says otherwise.
   HAVE_DECL_LOCALTIME_R=1;               AC_SUBST([HAVE_DECL_LOCALTIME_R])
   HAVE_NANOSLEEP=1;                      AC_SUBST([HAVE_NANOSLEEP])
   HAVE_STRPTIME=1;                       AC_SUBST([HAVE_STRPTIME])
   HAVE_TIMEGM=1;                         AC_SUBST([HAVE_TIMEGM])
+  HAVE_TZSET=1;                          AC_SUBST([HAVE_TZSET])
   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.
@@ -127,6 +129,7 @@ AC_DEFUN([gl_HEADER_TIME_H_DEFAULTS],
   REPLACE_NANOSLEEP=GNULIB_PORTCHECK;    AC_SUBST([REPLACE_NANOSLEEP])
   REPLACE_STRFTIME=GNULIB_PORTCHECK;     AC_SUBST([REPLACE_STRFTIME])
   REPLACE_TIMEGM=GNULIB_PORTCHECK;       AC_SUBST([REPLACE_TIMEGM])
+  REPLACE_TZSET=GNULIB_PORTCHECK;        AC_SUBST([REPLACE_TZSET])
 
   dnl Hack so that the time module doesn't depend on the sys_time module.
   dnl First, default GNULIB_GETTIMEOFDAY to 0 if sys_time is absent.
diff --git a/m4/time_rz.m4 b/m4/time_rz.m4
index 79060e00fcc..079e933b4e6 100644
--- a/m4/time_rz.m4
+++ b/m4/time_rz.m4
@@ -12,7 +12,6 @@ AC_DEFUN([gl_TIME_RZ],
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
   AC_REQUIRE([gl_HEADER_SYS_TIME_H_DEFAULTS])
   AC_REQUIRE([AC_STRUCT_TIMEZONE])
-  AC_CHECK_FUNCS_ONCE([tzset])
 
   AC_CHECK_TYPES([timezone_t], [], [], [[#include <time.h>]])
   if test "$ac_cv_type_timezone_t" = yes; then
diff --git a/src/editfns.c b/src/editfns.c
index 2dafd8e7b1b..38530437a2f 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -226,7 +226,7 @@ tzlookup (Lisp_Object zone, bool settz)
 void
 init_editfns (bool dumping)
 {
-#if !defined CANNOT_DUMP && defined HAVE_TZSET
+#if !defined CANNOT_DUMP
   /* A valid but unlikely setting for the TZ environment variable.
      It is OK (though a bit slower) if the user chooses this value.  */
   static char dump_tz_string[] = "TZ=UtC0";
@@ -245,17 +245,15 @@ init_editfns (bool dumping)
      and skip the rest of this function.  */
   if (dumping)
     {
-# ifdef HAVE_TZSET
       xputenv (dump_tz_string);
       tzset ();
-# endif
       return;
     }
 #endif
 
   char *tz = getenv ("TZ");
 
-#if !defined CANNOT_DUMP && defined HAVE_TZSET
+#if !defined CANNOT_DUMP
   /* If the execution TZ happens to be the same as the dump TZ,
      change it to some other value and then change it back,
      to force the underlying implementation to reload the TZ info.