Update from Gnulib by running admin/merge-gnulib

11 files changed, 211 insertions, 50 deletions

diff --git a/m4/canonicalize.m4 b/m4/canonicalize.m4
index 475fa15d6bd..0dfb2da9a6a 100644
--- a/m4/canonicalize.m4
+++ b/m4/canonicalize.m4
@@ -1,4 +1,4 @@
-# canonicalize.m4 serial 35
+# canonicalize.m4 serial 37
 
 dnl Copyright (C) 2003-2007, 2009-2021 Free Software Foundation, Inc.
 
@@ -78,68 +78,106 @@ AC_DEFUN([gl_CANONICALIZE_LGPL_SEPARATE],
 # so is the latter.
 AC_DEFUN([gl_FUNC_REALPATH_WORKS],
 [
-  AC_CHECK_FUNCS_ONCE([realpath])
+  AC_CHECK_FUNCS_ONCE([realpath lstat])
   AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
   AC_CACHE_CHECK([whether realpath works], [gl_cv_func_realpath_works], [
     rm -rf conftest.a conftest.d
     touch conftest.a
+    # Assume that if we have lstat, we can also check symlinks.
+    if test $ac_cv_func_lstat = yes; then
+      ln -s conftest.a conftest.l
+    fi
     mkdir conftest.d
     AC_RUN_IFELSE([
       AC_LANG_PROGRAM([[
         ]GL_NOCRASH[
+        #include <errno.h>
         #include <stdlib.h>
         #include <string.h>
       ]], [[
         int result = 0;
+        /* This test fails on Solaris 10.  */
         {
           char *name = realpath ("conftest.a", NULL);
           if (!(name && *name == '/'))
             result |= 1;
           free (name);
         }
+        /* This test fails on older versions of Cygwin.  */
         {
           char *name = realpath ("conftest.b/../conftest.a", NULL);
           if (name != NULL)
             result |= 2;
           free (name);
         }
+        /* This test fails on Cygwin 2.9.  */
+        #if HAVE_LSTAT
+        {
+          char *name = realpath ("conftest.l/../conftest.a", NULL);
+          if (name != NULL || errno != ENOTDIR)
+            result |= 4;
+          free (name);
+        }
+        #endif
+        /* This test fails on Mac OS X 10.13, OpenBSD 6.0.  */
         {
           char *name = realpath ("conftest.a/", NULL);
           if (name != NULL)
-            result |= 4;
+            result |= 8;
           free (name);
         }
+        /* This test fails on AIX 7, Solaris 10.  */
         {
           char *name1 = realpath (".", NULL);
           char *name2 = realpath ("conftest.d//./..", NULL);
           if (! name1 || ! name2 || strcmp (name1, name2))
-            result |= 8;
+            result |= 16;
           free (name1);
           free (name2);
         }
+        #ifdef __linux__
+        /* On Linux, // is the same as /. See also double-slash-root.m4.
+           realpath() should respect this.
+           This test fails on musl libc 1.2.2.  */
+        {
+          char *name = realpath ("//", NULL);
+          if (! name || strcmp (name, "/"))
+            result |= 32;
+          free (name);
+        }
+        #endif
         return result;
       ]])
      ],
      [gl_cv_func_realpath_works=yes],
-     [gl_cv_func_realpath_works=no],
+     [case $? in
+        32) gl_cv_func_realpath_works=nearly ;;
+        *)  gl_cv_func_realpath_works=no ;;
+      esac
+     ],
      [case "$host_os" in
                        # Guess yes on glibc systems.
         *-gnu* | gnu*) gl_cv_func_realpath_works="guessing yes" ;;
-                       # Guess yes on musl systems.
-        *-musl*)       gl_cv_func_realpath_works="guessing yes" ;;
+                       # Guess 'nearly' on musl systems.
+        *-musl*)       gl_cv_func_realpath_works="guessing nearly" ;;
+                       # Guess no on Cygwin.
+        cygwin*)       gl_cv_func_realpath_works="guessing no" ;;
                        # Guess no on native Windows.
         mingw*)        gl_cv_func_realpath_works="guessing no" ;;
                        # If we don't know, obey --enable-cross-guesses.
         *)             gl_cv_func_realpath_works="$gl_cross_guess_normal" ;;
       esac
      ])
-    rm -rf conftest.a conftest.d
+    rm -rf conftest.a conftest.l conftest.d
   ])
   case "$gl_cv_func_realpath_works" in
     *yes)
-      AC_DEFINE([FUNC_REALPATH_WORKS], [1], [Define to 1 if realpath()
-        can malloc memory, always gives an absolute path, and handles
-        trailing slash correctly.])
+      AC_DEFINE([FUNC_REALPATH_WORKS], [1],
+        [Define to 1 if realpath() can malloc memory, always gives an absolute path, and handles leading slashes and a trailing slash correctly.])
+      ;;
+    *nearly)
+      AC_DEFINE([FUNC_REALPATH_NEARLY_WORKS], [1],
+        [Define to 1 if realpath() can malloc memory, always gives an absolute path, and handles a trailing slash correctly.])
       ;;
   esac
 ])
diff --git a/m4/extensions.m4 b/m4/extensions.m4
index f7333acbd4f..5792a9557a8 100644
--- a/m4/extensions.m4
+++ b/m4/extensions.m4
@@ -1,4 +1,4 @@
-# serial 21  -*- Autoconf -*-
+# serial 22  -*- Autoconf -*-
 # Enable extensions on systems that normally disable them.
 
 # Copyright (C) 2003, 2006-2021 Free Software Foundation, Inc.
@@ -212,4 +212,16 @@ dnl it should only be defined when necessary.
 AC_DEFUN_ONCE([gl_USE_SYSTEM_EXTENSIONS],
 [
   AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+
+  dnl On OpenBSD 6.8 with GCC, the include files contain a couple of
+  dnl definitions that are only activated with an explicit -D_ISOC11_SOURCE.
+  dnl That's because this version of GCC (4.2.1) supports the option
+  dnl '-std=gnu99' but not the option '-std=gnu11'.
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  case "$host_os" in
+    openbsd*)
+      AC_DEFINE([_ISOC11_SOURCE], [1],
+        [Define to enable the declarations of ISO C 11 types and functions.])
+      ;;
+  esac
 ])
diff --git a/m4/fchmodat.m4 b/m4/fchmodat.m4
index 09380327799..66c0e308fcc 100644
--- a/m4/fchmodat.m4
+++ b/m4/fchmodat.m4
@@ -1,4 +1,4 @@
-# fchmodat.m4 serial 5
+# fchmodat.m4 serial 6
 dnl Copyright (C) 2004-2021 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -16,11 +16,9 @@ AC_DEFUN([gl_FUNC_FCHMODAT],
     HAVE_FCHMODAT=0
   else
     AC_CACHE_CHECK(
-      [whether fchmodat+AT_SYMLINK_NOFOLLOW works on non-symlinks],
+      [whether fchmodat works],
       [gl_cv_func_fchmodat_works],
-      [dnl This test fails on GNU/Linux with glibc 2.31 (but not on
-       dnl GNU/kFreeBSD nor GNU/Hurd) and Cygwin 2.9.
-       AC_RUN_IFELSE(
+      [AC_RUN_IFELSE(
          [AC_LANG_PROGRAM(
             [
               AC_INCLUDES_DEFAULT[
@@ -44,27 +42,49 @@ AC_DEFUN([gl_FUNC_FCHMODAT],
             [[
               int permissive = S_IRWXU | S_IRWXG | S_IRWXO;
               int desired = S_IRUSR | S_IWUSR;
-              static char const f[] = "conftest.fchmodat";
+              int result = 0;
+              #define file "conftest.fchmodat"
               struct stat st;
-              if (creat (f, permissive) < 0)
+              if (creat (file, permissive) < 0)
                 return 1;
-              if (fchmodat (AT_FDCWD, f, desired, AT_SYMLINK_NOFOLLOW) != 0)
+              /* Test whether fchmodat rejects a trailing slash on a non-directory.
+                 This test fails on AIX 7.2.  */
+              if (fchmodat (AT_FDCWD, file "/", desired, 0) == 0)
+                result |= 2;
+              /* Test whether fchmodat+AT_SYMLINK_NOFOLLOW works on non-symlinks.
+                 This test fails on GNU/Linux with glibc 2.31 (but not on
+                 GNU/kFreeBSD nor GNU/Hurd) and Cygwin 2.9.  */
+              if (fchmodat (AT_FDCWD, file, desired, AT_SYMLINK_NOFOLLOW) != 0)
+                result |= 4;
+              if (stat (file, &st) != 0)
                 return 1;
-              if (stat (f, &st) != 0)
-                return 1;
-              return ! ((st.st_mode & permissive) == desired);
+              if ((st.st_mode & permissive) != desired)
+                result |= 4;
+              return result;
             ]])],
          [gl_cv_func_fchmodat_works=yes],
-         [gl_cv_func_fchmodat_works=no],
+         [case $? in
+            2) gl_cv_func_fchmodat_works='nearly' ;;
+            *) gl_cv_func_fchmodat_works=no ;;
+          esac
+         ],
          [case "$host_os" in
-            dnl Guess no on Linux with glibc and Cygwin, yes otherwise.
+                                  # Guess no on Linux with glibc and Cygwin.
             linux-gnu* | cygwin*) gl_cv_func_fchmodat_works="guessing no" ;;
+                                  # Guess 'nearly' on AIX.
+            aix*)                 gl_cv_func_fchmodat_works="guessing nearly" ;;
+                                  # If we don't know, obey --enable-cross-guesses.
             *)                    gl_cv_func_fchmodat_works="$gl_cross_guess_normal" ;;
           esac
          ])
        rm -f conftest.fchmodat])
-    case $gl_cv_func_fchmodat_works in
+    case "$gl_cv_func_fchmodat_works" in
       *yes) ;;
+      *nearly)
+        AC_DEFINE([HAVE_NEARLY_WORKING_FCHMODAT], [1],
+          [Define to 1 if fchmodat works, except for the trailing slash handling.])
+        REPLACE_FCHMODAT=1
+        ;;
       *)
         AC_DEFINE([NEED_FCHMODAT_NONSYMLINK_FIX], [1],
           [Define to 1 if fchmodat+AT_SYMLINK_NOFOLLOW does not work right on non-symlinks.])
diff --git a/m4/gnulib-common.m4 b/m4/gnulib-common.m4
index 535359b2cf6..f2eff10de6d 100644
--- a/m4/gnulib-common.m4
+++ b/m4/gnulib-common.m4
@@ -39,11 +39,12 @@ AC_DEFUN([gl_COMMON_BODY], [
        this syntax with 'extern'.  */
 #  define _Noreturn [[noreturn]]
 # elif ((!defined __cplusplus || defined __clang__) \
-        && (201112 <= (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0)  \
-            || _GL_GNUC_PREREQ (4, 7) \
-            || (defined __apple_build_version__ \
-                ? 6000000 <= __apple_build_version__ \
-                : 3 < __clang_major__ + (5 <= __clang_minor__))))
+        && (201112 <= (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) \
+            || (!defined __STRICT_ANSI__ \
+                && (_GL_GNUC_PREREQ (4, 7) \
+                    || (defined __apple_build_version__ \
+                        ? 6000000 <= __apple_build_version__ \
+                        : 3 < __clang_major__ + (5 <= __clang_minor__))))))
    /* _Noreturn works as-is.  */
 # elif _GL_GNUC_PREREQ (2, 8) || defined __clang__ || 0x5110 <= __SUNPRO_C
 #  define _Noreturn __attribute__ ((__noreturn__))
@@ -66,7 +67,9 @@ AC_DEFUN([gl_COMMON_BODY], [
 #endif])
   AH_VERBATIM([attribute],
 [/* Attributes.  */
-#ifdef __has_attribute
+#if (defined __has_attribute \
+     && (!defined __clang_minor__ \
+         || 3 < __clang_major__ + (5 <= __clang_minor__)))
 # define _GL_HAS_ATTRIBUTE(attr) __has_attribute (__##attr##__)
 #else
 # define _GL_HAS_ATTRIBUTE(attr) _GL_ATTR_##attr
diff --git a/m4/gnulib-comp.m4 b/m4/gnulib-comp.m4
index ad109520dd1..cd6f7b4bbdf 100644
--- a/m4/gnulib-comp.m4
+++ b/m4/gnulib-comp.m4
@@ -75,6 +75,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module dtoastr:
   # Code from module dtotimespec:
   # Code from module dup2:
+  # Code from module dynarray:
   # Code from module eloop-threshold:
   # Code from module environ:
   # Code from module errno:
@@ -517,6 +518,7 @@ AC_DEFUN([gl_INIT],
   gl_gnulib_enabled_260941c0e5dc67ec9e87d1fb321c300b=false
   gl_gnulib_enabled_cloexec=false
   gl_gnulib_enabled_dirfd=false
+  gl_gnulib_enabled_dynarray=false
   gl_gnulib_enabled_925677f0343de64b89a9f0c790b4104c=false
   gl_gnulib_enabled_euidaccess=false
   gl_gnulib_enabled_getdtablesize=false
@@ -564,6 +566,12 @@ AC_DEFUN([gl_INIT],
       gl_gnulib_enabled_dirfd=true
     fi
   }
+  func_gl_gnulib_m4code_dynarray ()
+  {
+    if ! $gl_gnulib_enabled_dynarray; then
+      gl_gnulib_enabled_dynarray=true
+    fi
+  }
   func_gl_gnulib_m4code_925677f0343de64b89a9f0c790b4104c ()
   {
     if ! $gl_gnulib_enabled_925677f0343de64b89a9f0c790b4104c; then
@@ -797,6 +805,9 @@ AC_DEFUN([gl_INIT],
   if test $HAVE_READLINKAT = 0 || test $REPLACE_READLINKAT = 1; then
     func_gl_gnulib_m4code_03e0aaad4cb89ca757653bd367a6ccb7
   fi
+  if test $ac_use_included_regex = yes; then
+    func_gl_gnulib_m4code_dynarray
+  fi
   if { test $HAVE_DECL_STRTOIMAX = 0 || test $REPLACE_STRTOIMAX = 1; } && test $ac_cv_type_long_long_int = yes; then
     func_gl_gnulib_m4code_strtoll
   fi
@@ -819,6 +830,7 @@ AC_DEFUN([gl_INIT],
   AM_CONDITIONAL([gl_GNULIB_ENABLED_260941c0e5dc67ec9e87d1fb321c300b], [$gl_gnulib_enabled_260941c0e5dc67ec9e87d1fb321c300b])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_cloexec], [$gl_gnulib_enabled_cloexec])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_dirfd], [$gl_gnulib_enabled_dirfd])
+  AM_CONDITIONAL([gl_GNULIB_ENABLED_dynarray], [$gl_gnulib_enabled_dynarray])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_925677f0343de64b89a9f0c790b4104c], [$gl_gnulib_enabled_925677f0343de64b89a9f0c790b4104c])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_euidaccess], [$gl_gnulib_enabled_euidaccess])
   AM_CONDITIONAL([gl_GNULIB_ENABLED_getdtablesize], [$gl_gnulib_enabled_getdtablesize])
@@ -1021,6 +1033,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/dtoastr.c
   lib/dtotimespec.c
   lib/dup2.c
+  lib/dynarray.h
   lib/eloop-threshold.h
   lib/errno.in.h
   lib/euidaccess.c
@@ -1076,6 +1089,13 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/libc-config.h
   lib/limits.in.h
   lib/lstat.c
+  lib/malloc/dynarray-skeleton.c
+  lib/malloc/dynarray.h
+  lib/malloc/dynarray_at_failure.c
+  lib/malloc/dynarray_emplace_enlarge.c
+  lib/malloc/dynarray_finalize.c
+  lib/malloc/dynarray_resize.c
+  lib/malloc/dynarray_resize_clear.c
   lib/malloc/scratch_buffer.h
   lib/malloc/scratch_buffer_dupfree.c
   lib/malloc/scratch_buffer_grow.c
diff --git a/m4/nstrftime.m4 b/m4/nstrftime.m4
index 4674442810b..b510554b947 100644
--- a/m4/nstrftime.m4
+++ b/m4/nstrftime.m4
@@ -1,4 +1,4 @@
-# serial 36
+# serial 37
 
 # Copyright (C) 1996-1997, 1999-2007, 2009-2021 Free Software Foundation, Inc.
 #
@@ -12,7 +12,7 @@ AC_DEFUN([gl_FUNC_GNU_STRFTIME],
 [
  AC_REQUIRE([AC_C_RESTRICT])
 
- # This defines (or not) HAVE_TZNAME and HAVE_TM_ZONE.
+ # This defines (or not) HAVE_TZNAME and HAVE_STRUCT_TM_TM_ZONE.
  AC_REQUIRE([AC_STRUCT_TIMEZONE])
 
  AC_REQUIRE([gl_TM_GMTOFF])
diff --git a/m4/stddef_h.m4 b/m4/stddef_h.m4
index 18e872f483e..cd666c4a58c 100644
--- a/m4/stddef_h.m4
+++ b/m4/stddef_h.m4
@@ -1,14 +1,19 @@
-dnl A placeholder for <stddef.h>, for platforms that have issues.
-# stddef_h.m4 serial 7
+# stddef_h.m4 serial 9
 dnl Copyright (C) 2009-2021 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.
 
+dnl A placeholder for <stddef.h>, for platforms that have issues.
+
 AC_DEFUN([gl_STDDEF_H],
 [
   AC_REQUIRE([gl_STDDEF_H_DEFAULTS])
   AC_REQUIRE([gt_TYPE_WCHAR_T])
+
+  dnl Persuade OpenBSD <stddef.h> to declare max_align_t.
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
   STDDEF_H=
 
   dnl Test whether the type max_align_t exists and whether its alignment
@@ -23,6 +28,13 @@ AC_DEFUN([gl_STDDEF_H],
             int check1[2 * (__alignof__ (double) <= __alignof__ (max_align_t)) - 1];
             int check2[2 * (__alignof__ (long double) <= __alignof__ (max_align_t)) - 1];
             #endif
+            typedef struct { char a; max_align_t b; } max_helper;
+            typedef struct { char a; long b; } long_helper;
+            typedef struct { char a; double b; } double_helper;
+            typedef struct { char a; long double b; } long_double_helper;
+            int check3[2 * (offsetof (long_helper, b) <= offsetof (max_helper, b)) - 1];
+            int check4[2 * (offsetof (double_helper, b) <= offsetof (max_helper, b)) - 1];
+            int check5[2 * (offsetof (long_double_helper, b) <= offsetof (max_helper, b)) - 1];
           ]])],
        [gl_cv_type_max_align_t=yes],
        [gl_cv_type_max_align_t=no])
diff --git a/m4/string_h.m4 b/m4/string_h.m4
index 3e65355735c..a4cc5b43783 100644
--- a/m4/string_h.m4
+++ b/m4/string_h.m4
@@ -5,7 +5,7 @@
 # gives unlimited permission to copy and/or distribute it,
 # with or without modifications, as long as this notice is preserved.
 
-# serial 28
+# serial 29
 
 # Written by Paul Eggert.
 
@@ -113,6 +113,7 @@ AC_DEFUN([gl_HEADER_STRING_H_DEFAULTS],
   HAVE_SIGDESCR_NP=1;           AC_SUBST([HAVE_SIGDESCR_NP])
   HAVE_DECL_STRSIGNAL=1;        AC_SUBST([HAVE_DECL_STRSIGNAL])
   HAVE_STRVERSCMP=1;            AC_SUBST([HAVE_STRVERSCMP])
+  REPLACE_FFSLL=0;              AC_SUBST([REPLACE_FFSLL])
   REPLACE_MEMCHR=0;             AC_SUBST([REPLACE_MEMCHR])
   REPLACE_MEMMEM=0;             AC_SUBST([REPLACE_MEMMEM])
   REPLACE_STPNCPY=0;            AC_SUBST([REPLACE_STPNCPY])
diff --git a/m4/sys_stat_h.m4 b/m4/sys_stat_h.m4
index e8eac71b466..23cbdd28eb2 100644
--- a/m4/sys_stat_h.m4
+++ b/m4/sys_stat_h.m4
@@ -1,4 +1,4 @@
-# sys_stat_h.m4 serial 36   -*- Autoconf -*-
+# sys_stat_h.m4 serial 38   -*- Autoconf -*-
 dnl Copyright (C) 2006-2021 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -104,7 +104,9 @@ AC_DEFUN([gl_SYS_STAT_H_DEFAULTS],
   REPLACE_LSTAT=0;      AC_SUBST([REPLACE_LSTAT])
   REPLACE_MKDIR=0;      AC_SUBST([REPLACE_MKDIR])
   REPLACE_MKFIFO=0;     AC_SUBST([REPLACE_MKFIFO])
+  REPLACE_MKFIFOAT=0;   AC_SUBST([REPLACE_MKFIFOAT])
   REPLACE_MKNOD=0;      AC_SUBST([REPLACE_MKNOD])
+  REPLACE_MKNODAT=0;    AC_SUBST([REPLACE_MKNODAT])
   REPLACE_STAT=0;       AC_SUBST([REPLACE_STAT])
   REPLACE_UTIMENSAT=0;  AC_SUBST([REPLACE_UTIMENSAT])
 ])
diff --git a/m4/time_h.m4 b/m4/time_h.m4
index 07e6967e45b..b6a1aa3bc0f 100644
--- a/m4/time_h.m4
+++ b/m4/time_h.m4
@@ -2,7 +2,7 @@
 
 # Copyright (C) 2000-2001, 2003-2007, 2009-2021 Free Software Foundation, Inc.
 
-# serial 13
+# serial 15
 
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
@@ -25,6 +25,22 @@ AC_DEFUN([gl_HEADER_TIME_H_BODY],
   AC_REQUIRE([gl_CHECK_TYPE_STRUCT_TIMESPEC])
 
   AC_REQUIRE([AC_C_RESTRICT])
+
+  AC_CACHE_CHECK([for TIME_UTC in <time.h>],
+    [gl_cv_time_h_has_TIME_UTC],
+    [AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[#include <time.h>
+          ]],
+          [[static int x = TIME_UTC; x++;]])],
+       [gl_cv_time_h_has_TIME_UTC=yes],
+       [gl_cv_time_h_has_TIME_UTC=no])])
+  if test $gl_cv_time_h_has_TIME_UTC = yes; then
+    TIME_H_DEFINES_TIME_UTC=1
+  else
+    TIME_H_DEFINES_TIME_UTC=0
+  fi
+  AC_SUBST([TIME_H_DEFINES_TIME_UTC])
 ])
 
 dnl Check whether 'struct timespec' is declared
@@ -113,6 +129,7 @@ AC_DEFUN([gl_HEADER_TIME_H_DEFAULTS],
   GNULIB_STRFTIME=0;                     AC_SUBST([GNULIB_STRFTIME])
   GNULIB_STRPTIME=0;                     AC_SUBST([GNULIB_STRPTIME])
   GNULIB_TIMEGM=0;                       AC_SUBST([GNULIB_TIMEGM])
+  GNULIB_TIMESPEC_GET=0;                 AC_SUBST([GNULIB_TIMESPEC_GET])
   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])
@@ -123,6 +140,7 @@ AC_DEFUN([gl_HEADER_TIME_H_DEFAULTS],
   HAVE_NANOSLEEP=1;                      AC_SUBST([HAVE_NANOSLEEP])
   HAVE_STRPTIME=1;                       AC_SUBST([HAVE_STRPTIME])
   HAVE_TIMEGM=1;                         AC_SUBST([HAVE_TIMEGM])
+  HAVE_TIMESPEC_GET=1;                   AC_SUBST([HAVE_TIMESPEC_GET])
   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.
diff --git a/m4/utimensat.m4 b/m4/utimensat.m4
index bdabe24c568..b5bff1651f3 100644
--- a/m4/utimensat.m4
+++ b/m4/utimensat.m4
@@ -1,4 +1,4 @@
-# serial 7
+# serial 9
 # See if we need to provide utimensat replacement.
 
 dnl Copyright (C) 2009-2021 Free Software Foundation, Inc.
@@ -12,6 +12,7 @@ AC_DEFUN([gl_FUNC_UTIMENSAT],
 [
   AC_REQUIRE([gl_SYS_STAT_H_DEFAULTS])
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
   AC_CHECK_FUNCS_ONCE([utimensat])
   if test $ac_cv_func_utimensat = no; then
     HAVE_UTIMENSAT=0
@@ -28,10 +29,19 @@ AC_DEFUN([gl_FUNC_UTIMENSAT],
               const char *f = "conftest.file";
               if (close (creat (f, 0600)))
                 return 1;
+              /* Test whether a trailing slash is handled correctly.
+                 This fails on AIX 7.2.  */
+              {
+                struct timespec ts[2];
+                ts[0].tv_sec = 345183300; ts[0].tv_nsec = 0;
+                ts[1] = ts[0];
+                if (utimensat (AT_FDCWD, "conftest.file/", ts, 0) == 0)
+                  result |= 2;
+              }
               /* Test whether the AT_SYMLINK_NOFOLLOW flag is supported.  */
               {
                 if (utimensat (AT_FDCWD, f, NULL, AT_SYMLINK_NOFOLLOW))
-                  result |= 2;
+                  result |= 4;
               }
               /* Test whether UTIME_NOW and UTIME_OMIT work.  */
               {
@@ -41,7 +51,7 @@ AC_DEFUN([gl_FUNC_UTIMENSAT],
                 ts[1].tv_sec = 1;
                 ts[1].tv_nsec = UTIME_NOW;
                 if (utimensat (AT_FDCWD, f, ts, 0))
-                  result |= 4;
+                  result |= 8;
               }
               sleep (1);
               {
@@ -52,19 +62,44 @@ AC_DEFUN([gl_FUNC_UTIMENSAT],
                 ts[1].tv_sec = 1;
                 ts[1].tv_nsec = UTIME_OMIT;
                 if (utimensat (AT_FDCWD, f, ts, 0))
-                  result |= 8;
-                if (stat (f, &st))
                   result |= 16;
-                else if (st.st_ctime < st.st_atime)
+                if (stat (f, &st))
                   result |= 32;
+                else if (st.st_ctime < st.st_atime)
+                  result |= 64;
               }
               return result;
             ]])],
          [gl_cv_func_utimensat_works=yes],
-         [gl_cv_func_utimensat_works=no],
-         [gl_cv_func_utimensat_works="guessing yes"])])
-    if test "$gl_cv_func_utimensat_works" = no; then
-      REPLACE_UTIMENSAT=1
-    fi
+         [case $? in
+            2) gl_cv_func_utimensat_works='nearly' ;;
+            *) gl_cv_func_utimensat_works=no ;;
+          esac
+         ],
+         [case "$host_os" in
+            # Guess yes on Linux or glibc systems.
+            linux-* | linux | *-gnu* | gnu*)
+              gl_cv_func_utimensat_works="guessing yes" ;;
+            # Guess 'nearly' on AIX.
+            aix*)
+              gl_cv_func_utimensat_works="guessing nearly" ;;
+            # If we don't know, obey --enable-cross-guesses.
+            *)
+              gl_cv_func_utimensat_works="$gl_cross_guess_normal" ;;
+          esac
+         ])
+      ])
+    case "$gl_cv_func_utimensat_works" in
+      *yes)
+        ;;
+      *nearly)
+        AC_DEFINE([HAVE_NEARLY_WORKING_UTIMENSAT], [1],
+          [Define to 1 if utimensat works, except for the trailing slash handling.])
+        REPLACE_UTIMENSAT=1
+        ;;
+      *)
+        REPLACE_UTIMENSAT=1
+        ;;
+    esac
   fi
 ])