Update from Gnulib by running admin/merge-gnulib

18 files changed, 503 insertions, 212 deletions

diff --git a/lib/_Noreturn.h b/lib/_Noreturn.h
index 0d452649fb2..8e63387914c 100644
--- a/lib/_Noreturn.h
+++ b/lib/_Noreturn.h
@@ -14,33 +14,25 @@
    You should have received a copy of the GNU Lesser General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
 
+/* The _Noreturn keyword of C11.
+   Do not use [[noreturn]], because with it the syntax
+     extern _Noreturn void func (...);
+   would not be valid; such a declaration would be valid only with 'extern'
+   and '_Noreturn' swapped, or without the 'extern' keyword.  However, some
+   AIX system header files and several gnulib header files use precisely
+   this syntax with 'extern'.  So even though C23 deprecates _Noreturn,
+   it is currently more portable to prefer it to [[noreturn]].
+
+   Also, do not try to work around LLVM bug 59792 (clang 15 or earlier).
+   This rare bug can be worked around by compiling with 'clang -D_Noreturn=',
+   though the workaround may generate many false-alarm warnings.  */
 #ifndef _Noreturn
-# if (defined __cplusplus \
-      && ((201103 <= __cplusplus && !(__GNUC__ == 4 && __GNUC_MINOR__ == 7)) \
-          || (defined _MSC_VER && 1900 <= _MSC_VER)) \
-      && 0)
-    /* [[noreturn]] is not practically usable, because with it the syntax
-         extern _Noreturn void func (...);
-       would not be valid; such a declaration would only be valid with 'extern'
-       and '_Noreturn' swapped, or without the 'extern' keyword.  However, some
-       AIX system header files and several gnulib header files use precisely
-       this syntax with 'extern'.  */
-#  define _Noreturn [[noreturn]]
-# elif (defined __clang__ && __clang_major__ < 16 \
-        && defined _GL_WORK_AROUND_LLVM_BUG_59792)
-   /* Compile with -D_GL_WORK_AROUND_LLVM_BUG_59792 to work around
-      that rare LLVM bug, though you may get many false-alarm warnings.  */
-#  define _Noreturn
-# elif ((!defined __cplusplus || defined __clang__) \
-        && (201112 <= (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) \
-            || (!defined __STRICT_ANSI__ \
-                && (4 < __GNUC__ + (7 <= __GNUC_MINOR__) && !defined __clang__ \
-                    || (defined __apple_build_version__ \
-                        ? 6000000 <= __apple_build_version__ \
-                        : 3 < __clang_major__ + (5 <= __clang_minor__))))))
+# if 201112 <= (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0)
    /* _Noreturn works as-is.  */
 # elif (2 < __GNUC__ + (8 <= __GNUC_MINOR__) || defined __clang__ \
         || 0x5110 <= __SUNPRO_C)
+   /* Prefer __attribute__ ((__noreturn__)) to plain _Noreturn even if the
+      latter works, as 'gcc -std=gnu99 -Wpedantic' warns about _Noreturn.  */
 #  define _Noreturn __attribute__ ((__noreturn__))
 # elif 1200 <= (defined _MSC_VER ? _MSC_VER : 0)
 #  define _Noreturn __declspec (noreturn)
diff --git a/lib/acl.h b/lib/acl.h
index 90fd24e152d..e3c134fb41c 100644
--- a/lib/acl.h
+++ b/lib/acl.h
@@ -79,6 +79,8 @@ struct aclinfo
 bool acl_errno_valid (int) _GL_ATTRIBUTE_CONST;
 int file_has_acl (char const *, struct stat const *);
 int file_has_aclinfo (char const *restrict, struct aclinfo *restrict, int);
+int fdfile_has_aclinfo (int, char const *restrict,
+                        struct aclinfo *restrict, int);
 
 #if HAVE_LINUX_XATTR_H && HAVE_LISTXATTR
 bool aclinfo_has_xattr (struct aclinfo const *, char const *)
diff --git a/lib/attribute.h b/lib/attribute.h
index ae7bbe8e2cb..c85412d90af 100644
--- a/lib/attribute.h
+++ b/lib/attribute.h
@@ -50,8 +50,9 @@
              - In a function declaration/definition with a storage-class
                specifier: between the storage-class specifier and the return
                type.
-        - Or after the parameter list,
-          ∙ but after ATTRIBUTE_NOTHROW if present.
+        - Or, in a function declaration:
+          after the parameter list,
+            ∙ but after ATTRIBUTE_NOTHROW if present.
 
    In other declarations, such as variable declarations:
 
diff --git a/lib/boot-time.h b/lib/boot-time.h
index 195839a2c53..7abfa12e444 100644
--- a/lib/boot-time.h
+++ b/lib/boot-time.h
@@ -29,11 +29,16 @@ extern "C" {
 /* Store the approximate time when the machine last booted in *P_BOOT_TIME,
    and return 0.  If it cannot be determined, return -1.
 
+   If the machine is a container inside another host machine,
+   return the boot time of the container, not the host.
+   The difference can matter in GNU/Linux, where times in /proc/stat
+   might be relative to boot time of the host, not the container.
+
    This function is not multithread-safe, since on many platforms it
-   invokes the functions setutxent, getutxent, endutxent.  These
-   functions are needed because they may lock FILE (so that we don't
-   read garbage when a concurrent process writes to FILE), but their
-   drawback is that they have a common global state.  */
+   invokes the functions setutxent, getutxent, endutxent.
+   These functions may lock a file like /var/log/wtmp (so that we
+   don't read garbage when a concurrent process writes to that file),
+   but their drawback is that they have a common global state.  */
 extern int get_boot_time (struct timespec *p_boot_time);
 
 
diff --git a/lib/fcntl.in.h b/lib/fcntl.in.h
index d7f551b30f3..c5068ed48a0 100644
--- a/lib/fcntl.in.h
+++ b/lib/fcntl.in.h
@@ -209,7 +209,9 @@ _GL_WARN_ON_USE (open, "open is not always POSIX compliant - "
 #   undef open
 #   define open _open
 #  endif
-_GL_CXXALIAS_MDA (open, int, (const char *filename, int flags, ...));
+/* Need to cast, because in MSVC the parameter list of _open as a C++ function
+   is (const char *, int, int = 0).  */
+_GL_CXXALIAS_MDA_CAST (open, int, (const char *filename, int flags, ...));
 # else
 _GL_CXXALIAS_SYS (open, int, (const char *filename, int flags, ...));
 # endif
@@ -313,7 +315,7 @@ _GL_WARN_ON_USE (openat, "openat is not portable - "
 #endif
 
 #ifndef O_DIRECTORY
-# define O_DIRECTORY 0
+# define O_DIRECTORY 0x20000000 /* Try to not collide with system O_* flags.  */
 #endif
 
 #ifndef O_DSYNC
diff --git a/lib/file-has-acl.c b/lib/file-has-acl.c
index 66b920c1ab2..a9cfbf3a16e 100644
--- a/lib/file-has-acl.c
+++ b/lib/file-has-acl.c
@@ -85,6 +85,13 @@ smack_new_label_from_path (MAYBE_UNUSED const char *path,
 {
   return -1;
 }
+static ssize_t
+smack_new_label_from_file (MAYBE_UNUSED int fd,
+                           MAYBE_UNUSED const char *xattr,
+                           MAYBE_UNUSED char **label)
+{
+  return -1;
+}
 # endif
 static bool
 is_smack_enabled (void)
@@ -115,14 +122,16 @@ aclinfo_may_indicate_xattr (struct aclinfo const *ai)
 
 static bool
 has_xattr (char const *xattr, struct aclinfo const *ai,
-           MAYBE_UNUSED char const *restrict name, MAYBE_UNUSED int flags)
+           int fd, char const *restrict name, int flags)
 {
   if (ai && aclinfo_has_xattr (ai, xattr))
     return true;
   else if (!ai || aclinfo_may_indicate_xattr (ai))
     {
-      int ret = ((flags & ACL_SYMLINK_FOLLOW ? getxattr : lgetxattr)
-                (name, xattr, NULL, 0));
+      int ret = (fd < 0
+                 ? ((flags & ACL_SYMLINK_FOLLOW ? getxattr : lgetxattr)
+                    (name, xattr, NULL, 0))
+                 : fgetxattr (fd, xattr, NULL, 0));
       if (0 <= ret || (errno == ERANGE || errno == E2BIG))
         return true;
     }
@@ -145,11 +154,12 @@ aclinfo_has_xattr (struct aclinfo const *ai, char const *xattr)
   return false;
 }
 
-/* Get attributes of the file NAME into AI, if USE_ACL.
+/* Get attributes of the file FD aka NAME into AI, if USE_ACL.
+   Ignore FD if it is negative.
    If FLAGS & ACL_GET_SCONTEXT, also get security context.
    If FLAGS & ACL_SYMLINK_FOLLOW, follow symbolic links.  */
 static void
-get_aclinfo (char const *name, struct aclinfo *ai, int flags)
+get_aclinfo (int fd, char const *name, struct aclinfo *ai, int flags)
 {
   int scontext_err = ENOTSUP;
   ai->buf = ai->u.__gl_acl_ch;
@@ -163,7 +173,9 @@ get_aclinfo (char const *name, struct aclinfo *ai, int flags)
         = (flags & ACL_SYMLINK_FOLLOW ? listxattr : llistxattr);
       while (true)
         {
-          ai->size = lsxattr (name, ai->buf, acl_alloc);
+          ai->size = (fd < 0
+                      ? lsxattr (name, ai->buf, acl_alloc)
+                      : flistxattr (fd, ai->buf, acl_alloc));
           if (0 < ai->size)
             break;
           ai->u.err = ai->size < 0 ? errno : 0;
@@ -171,7 +183,9 @@ get_aclinfo (char const *name, struct aclinfo *ai, int flags)
             break;
 
           /* The buffer was too small.  Find how large it should have been.  */
-          ssize_t size = lsxattr (name, NULL, 0);
+          ssize_t size = (fd < 0
+                          ? lsxattr (name, NULL, 0)
+                          : flistxattr (fd, NULL, 0));
           if (size <= 0)
             {
               ai->size = size;
@@ -214,9 +228,13 @@ get_aclinfo (char const *name, struct aclinfo *ai, int flags)
         {
           if (ai->size < 0 || aclinfo_has_xattr (ai, XATTR_NAME_SMACK))
             {
-              ssize_t r = smack_new_label_from_path (name, "security.SMACK64",
-                                                     flags & ACL_SYMLINK_FOLLOW,
-                                                     &ai->scontext);
+              static char const SMACK64[] = "security.SMACK64";
+              ssize_t r =
+                (fd < 0
+                 ? smack_new_label_from_path (name, SMACK64,
+                                              flags & ACL_SYMLINK_FOLLOW,
+                                              &ai->scontext)
+                 : smack_new_label_from_file (fd, SMACK64, &ai->scontext));
               scontext_err = r < 0 ? errno : 0;
             }
         }
@@ -226,8 +244,10 @@ get_aclinfo (char const *name, struct aclinfo *ai, int flags)
           if (ai->size < 0 || aclinfo_has_xattr (ai, XATTR_NAME_SELINUX))
             {
               ssize_t r =
-                ((flags & ACL_SYMLINK_FOLLOW ? getfilecon : lgetfilecon)
-                 (name, &ai->scontext));
+                (fd < 0
+                 ? ((flags & ACL_SYMLINK_FOLLOW ? getfilecon : lgetfilecon)
+                    (name, &ai->scontext))
+                 : fgetfilecon (fd, &ai->scontext));
               scontext_err = r < 0 ? errno : 0;
 #  ifndef SE_SELINUX_INLINE
               /* Gnulib's selinux-h module is not in use, so getfilecon and
@@ -362,11 +382,14 @@ acl_nfs4_nontrivial (uint32_t *xattr, ssize_t nbytes)
 }
 #endif
 
-#if (!USE_LINUX_XATTR && USE_ACL && HAVE_ACL_GET_FD \
-     && !HAVE_ACL_EXTENDED_FILE && !HAVE_ACL_TYPE_EXTENDED \
-     && !HAVE_ACL_GET_LINK_NP)
-# include <fcntl.h>
-# ifdef O_PATH
+#if (!USE_LINUX_XATTR && USE_ACL && HAVE_ACL_GET_FILE \
+     && !HAVE_ACL_EXTENDED_FILE && !HAVE_ACL_TYPE_EXTENDED)
+/* FreeBSD, NetBSD >= 10, IRIX, Tru64, Cygwin >= 2.5 */
+
+# if HAVE_ACL_GET_FD && !HAVE_ACL_GET_LINK_NP /* IRIX, Tru64, Cygwin >= 2.5 */
+#  include <fcntl.h>
+#  ifdef O_PATH
+#   define acl_get_fd_np(fd, type) acl_get_fd (fd)
 
 /* Like acl_get_file, but do not follow symbolic links.  */
 static acl_t
@@ -381,8 +404,24 @@ acl_get_link_np (char const *name, acl_type_t type)
   errno = err;
   return r;
 }
-#  define HAVE_ACL_GET_LINK_NP 1
+#   define HAVE_ACL_GET_LINK_NP 1
+#  endif
 # endif
+
+static acl_t
+acl_get_fdfile (int fd, char const *name, acl_type_t type, int flags)
+{
+  acl_t (*get) (char const *, acl_type_t) = acl_get_file;
+# if HAVE_ACL_GET_LINK_NP /* FreeBSD, NetBSD >= 10, Cygwin >= 2.5 */
+  if (0 <= fd)
+    return acl_get_fd_np (fd, type);
+  if (! (flags & ACL_SYMLINK_FOLLOW))
+    get = acl_get_link_np;
+# else
+  /* Ignore FD and FLAGS, unfortunately.  */
+# endif
+  return get (name, type);
+}
 #endif
 
 /* Return 1 if NAME has a nontrivial access control list,
@@ -398,14 +437,35 @@ acl_get_link_np (char const *name, acl_type_t type)
    If the d_type value is not known, use DT_UNKNOWN though this may be less
    efficient.  */
 int
-file_has_aclinfo (MAYBE_UNUSED char const *restrict name,
+file_has_aclinfo (char const *restrict name,
                   struct aclinfo *restrict ai, int flags)
 {
+  return fdfile_has_aclinfo (-1, name, ai, flags);
+}
+
+/* Return 1 if FD aka NAME has a nontrivial access control list,
+   0 if ACLs are not supported, or if NAME has no or only a base ACL,
+   and -1 (setting errno) on error.  Note callers can determine
+   if ACLs are not supported as errno is set in that case also.
+   Ignore FD if it is negative.
+   Set *AI to ACL info regardless of return value.
+   FLAGS should be a <dirent.h> d_type value, optionally ORed with
+     - _GL_DT_NOTDIR if it is known that NAME is not a directory,
+     - ACL_GET_SCONTEXT to retrieve security context and return 1 if present,
+     - ACL_SYMLINK_FOLLOW to follow the link if NAME is a symbolic link;
+       otherwise do not follow them if possible.
+   If the d_type value is not known, use DT_UNKNOWN though this may be less
+   efficient.  */
+int
+fdfile_has_aclinfo (MAYBE_UNUSED int fd,
+                    MAYBE_UNUSED char const *restrict name,
+                    struct aclinfo *restrict ai, int flags)
+{
   MAYBE_UNUSED unsigned char d_type = flags & UCHAR_MAX;
 
 #if USE_LINUX_XATTR
   int initial_errno = errno;
-  get_aclinfo (name, ai, flags);
+  get_aclinfo (fd, name, ai, flags);
 
   if (!aclinfo_may_indicate_xattr (ai) && ai->size <= 0)
     {
@@ -418,11 +478,11 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name,
      In earlier Fedora the two types of ACLs were mutually exclusive.
      Attempt to work correctly on both kinds of systems.  */
 
-  if (!has_xattr (XATTR_NAME_NFSV4_ACL, ai, name, flags))
+  if (!has_xattr (XATTR_NAME_NFSV4_ACL, ai, fd, name, flags))
     return
-      (has_xattr (XATTR_NAME_POSIX_ACL_ACCESS, ai, name, flags)
+      (has_xattr (XATTR_NAME_POSIX_ACL_ACCESS, ai, fd, name, flags)
        || ((d_type == DT_DIR || d_type == DT_UNKNOWN)
-           && has_xattr (XATTR_NAME_POSIX_ACL_DEFAULT, ai, name, flags)));
+           && has_xattr (XATTR_NAME_POSIX_ACL_DEFAULT, ai, fd, name, flags)));
 
   /* A buffer large enough to hold any trivial NFSv4 ACL.
      The max length of a trivial NFSv4 ACL is 6 words for owner,
@@ -432,8 +492,10 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name,
      everyone is another word to hold "EVERYONE@".  */
   uint32_t buf[2 * (6 + 6 + 7)];
 
-  int ret = ((flags & ACL_SYMLINK_FOLLOW ? getxattr : lgetxattr)
-             (name, XATTR_NAME_NFSV4_ACL, buf, sizeof buf));
+  int ret = (fd < 0
+             ? ((flags & ACL_SYMLINK_FOLLOW ? getxattr : lgetxattr)
+                (name, XATTR_NAME_NFSV4_ACL, buf, sizeof buf))
+             : fgetxattr (fd, XATTR_NAME_NFSV4_ACL, buf, sizeof buf));
   if (ret < 0)
     switch (errno)
       {
@@ -467,20 +529,23 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name,
       /* On Linux, acl_extended_file is an optimized function: It only
          makes two calls to getxattr(), one for ACL_TYPE_ACCESS, one for
          ACL_TYPE_DEFAULT.  */
-    ret = ((flags & ACL_SYMLINK_FOLLOW
-            ? acl_extended_file
-            : acl_extended_file_nofollow)
-           (name));
+    ret = (fd < 0
+           ? ((flags & ACL_SYMLINK_FOLLOW
+               ? acl_extended_file
+               : acl_extended_file_nofollow)
+              (name))
+           : acl_extended_fd (fd));
 #   elif HAVE_ACL_TYPE_EXTENDED /* Mac OS X */
     /* On Mac OS X, acl_get_file (name, ACL_TYPE_ACCESS)
        and acl_get_file (name, ACL_TYPE_DEFAULT)
        always return NULL / EINVAL.  There is no point in making
        these two useless calls.  The real ACL is retrieved through
-       acl_get_file (name, ACL_TYPE_EXTENDED).  */
-    acl_t acl = ((flags & ACL_SYMLINK_FOLLOW
-                  ? acl_get_file
-                  : acl_get_link_np)
-                 (name, ACL_TYPE_EXTENDED));
+       ACL_TYPE_EXTENDED.  */
+    acl_t acl =
+      (fd < 0
+       ? ((flags & ACL_SYMLINK_FOLLOW ? acl_get_file : acl_get_link_np)
+          (name, ACL_TYPE_EXTENDED))
+       : acl_get_fd_np (fd, ACL_TYPE_EXTENDED));
     if (acl)
       {
         ret = acl_extended_nontrivial (acl);
@@ -489,13 +554,8 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name,
     else
       ret = -1;
 #   else /* FreeBSD, NetBSD >= 10, IRIX, Tru64, Cygwin >= 2.5 */
-    acl_t (*acl_get_file_or_link) (char const *, acl_type_t) = acl_get_file;
-#    if HAVE_ACL_GET_LINK_NP /* FreeBSD, NetBSD >= 10, Cygwin >= 2.5 */
-    if (! (flags & ACL_SYMLINK_FOLLOW))
-      acl_get_file_or_link = acl_get_link_np;
-#    endif
 
-    acl_t acl = acl_get_file_or_link (name, ACL_TYPE_ACCESS);
+    acl_t acl = acl_get_fdfile (fd, name, ACL_TYPE_ACCESS, flags);
     if (acl)
       {
         ret = acl_access_nontrivial (acl);
@@ -517,7 +577,7 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name,
             && (d_type == DT_DIR
                 || (d_type == DT_UNKNOWN && !(flags & _GL_DT_NOTDIR))))
           {
-            acl = acl_get_file_or_link (name, ACL_TYPE_DEFAULT);
+            acl = acl_get_fdfile (fd, name, ACL_TYPE_DEFAULT, flags);
             if (acl)
               {
 #     ifdef __CYGWIN__ /* Cygwin >= 2.5 */
@@ -562,7 +622,10 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name,
 
       /* Solaris 10 (newer version), which has additional API declared in
          <sys/acl.h> (acl_t) and implemented in libsec (acl_set, acl_trivial,
-         acl_fromtext, ...).  */
+         acl_fromtext, ...).
+
+         Ignore FD, unfortunately.  That is better than mishandling
+         ZFS-style ACLs, as the general case code does.  */
       return acl_trivial (name);
 
 #    else /* Solaris, Cygwin, general case */
@@ -586,7 +649,9 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name,
 
         for (;;)
           {
-            count = acl (name, GETACL, alloc, entries);
+            count = (fd < 0
+                     ? acl (name, GETACL, alloc, entries)
+                     : facl (fd, GETACL, alloc, entries));
             if (count < 0 && errno == ENOSPC)
               {
                 /* Increase the size of the buffer.  */
@@ -657,7 +722,9 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name,
 
         for (;;)
           {
-            count = acl (name, ACE_GETACL, alloc, entries);
+            count = (fd < 0
+                     ? acl (name, ACE_GETACL, alloc, entries)
+                     : facl (fd, ACE_GETACL, alloc, entries));
             if (count < 0 && errno == ENOSPC)
               {
                 /* Increase the size of the buffer.  */
@@ -722,7 +789,9 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name,
         struct acl_entry entries[NACLENTRIES];
         int count;
 
-        count = getacl (name, NACLENTRIES, entries);
+        count = (fd < 0
+                 ? getacl (name, NACLENTRIES, entries)
+                 : fgetacl (fd, NACLENTRIES, entries));
 
         if (count < 0)
           {
@@ -751,7 +820,8 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name,
             {
               struct stat statbuf;
 
-              if (stat (name, &statbuf) == -1 && errno != EOVERFLOW)
+              if ((fd < 0 ? stat (name, &statbuf) : fstat (fd, &statbuf)) < 0
+                  && errno != EOVERFLOW)
                 return -1;
 
               return acl_nontrivial (count, entries);
@@ -765,6 +835,7 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name,
         struct acl entries[NACLVENTRIES];
         int count;
 
+        /* Ignore FD, unfortunately.  */
         count = acl ((char *) name, ACL_GET, NACLVENTRIES, entries);
 
         if (count < 0)
@@ -809,7 +880,9 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name,
           /* The docs say that type being 0 is equivalent to ACL_ANY, but it
              is not true, in AIX 5.3.  */
           type.u64 = ACL_ANY;
-          if (aclx_get (name, 0, &type, aclbuf, &aclsize, &mode) >= 0)
+          if (0 <= (fd < 0
+                    ? aclx_get (name, 0, &type, aclbuf, &aclsize, &mode)
+                    : aclx_fget (fd, 0, &type, aclbuf, &aclsize, &mode)))
             break;
           if (errno == ENOSYS)
             return 0;
@@ -855,7 +928,10 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name,
 
       union { struct acl a; char room[4096]; } u;
 
-      if (statacl ((char *) name, STX_NORMAL, &u.a, sizeof (u)) < 0)
+      if ((fd < 0
+           ? statacl ((char *) name, STX_NORMAL, &u.a, sizeof u)
+           : fstatacl (fd, STX_NORMAL, &u.a, sizeof u))
+          < 0)
         return -1;
 
       return acl_nontrivial (&u.a);
@@ -866,6 +942,7 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name,
         struct acl entries[NACLENTRIES];
         int count;
 
+        /* Ignore FD, unfortunately.  */
         count = acl ((char *) name, ACL_GET, NACLENTRIES, entries);
 
         if (count < 0)
diff --git a/lib/gettext.h b/lib/gettext.h
index ea0c27e0002..fd6c62b7eb7 100644
--- a/lib/gettext.h
+++ b/lib/gettext.h
@@ -59,18 +59,61 @@
 #  endif
 # endif
 
-/* Disabled NLS.
-   The casts to 'const char *' serve the purpose of producing warnings
-   for invalid uses of the value returned from these functions.
-   On pre-ANSI systems without 'const', the config.h file is supposed to
-   contain "#define const".  */
-# undef gettext
-# define gettext(Msgid) ((const char *) (Msgid))
-# undef dgettext
-# define dgettext(Domainname, Msgid) ((void) (Domainname), gettext (Msgid))
-# undef dcgettext
-# define dcgettext(Domainname, Msgid, Category) \
-    ((void) (Category), dgettext (Domainname, Msgid))
+/* Disabled NLS.  */
+# if defined __GNUC__ && !defined __clang__ && !defined __cplusplus
+/* Use inline functions, to avoid warnings
+     warning: format not a string literal and no format arguments
+   that don't occur with enabled NLS.  */
+/* The return type 'const char *' serves the purpose of producing warnings
+   for invalid uses of the value returned from these functions.  */
+#  if __GNUC__ >= 9
+#   pragma GCC diagnostic push
+#   pragma GCC diagnostic ignored "-Wbuiltin-declaration-mismatch"
+#  endif
+__attribute__ ((__always_inline__, __gnu_inline__)) extern inline
+#  if !defined(__sun)
+const
+#  endif
+char *
+gettext (const char *msgid)
+{
+  return msgid;
+}
+__attribute__ ((__always_inline__, __gnu_inline__)) extern inline
+#  if !defined(__sun)
+const
+#  endif
+char *
+dgettext (const char *domain, const char *msgid)
+{
+  (void) domain;
+  return msgid;
+}
+__attribute__ ((__always_inline__, __gnu_inline__)) extern inline
+#  if !defined(__sun)
+const
+#  endif
+char *
+dcgettext (const char *domain, const char *msgid, int category)
+{
+  (void) domain;
+  (void) category;
+  return msgid;
+}
+#  if __GNUC__ >= 9
+#   pragma GCC diagnostic pop
+#  endif
+# else
+/* The casts to 'const char *' serve the purpose of producing warnings
+   for invalid uses of the value returned from these functions.  */
+#  undef gettext
+#  define gettext(Msgid) ((const char *) (Msgid))
+#  undef dgettext
+#  define dgettext(Domainname, Msgid) ((void) (Domainname), gettext (Msgid))
+#  undef dcgettext
+#  define dcgettext(Domainname, Msgid, Category) \
+     ((void) (Category), dgettext (Domainname, Msgid))
+# endif
 # undef ngettext
 # define ngettext(Msgid1, Msgid2, N) \
     ((N) == 1 \
diff --git a/lib/gnulib.mk.in b/lib/gnulib.mk.in
index fb34cf2cc1d..bb147b69eed 100644
--- a/lib/gnulib.mk.in
+++ b/lib/gnulib.mk.in
@@ -739,6 +739,9 @@ HAVE_CANONICALIZE_FILE_NAME = @HAVE_CANONICALIZE_FILE_NAME@
 HAVE_CHOWN = @HAVE_CHOWN@
 HAVE_CLOSEDIR = @HAVE_CLOSEDIR@
 HAVE_COPY_FILE_RANGE = @HAVE_COPY_FILE_RANGE@
+HAVE_CXX_STDCKDINT_H = @HAVE_CXX_STDCKDINT_H@
+HAVE_C_STDCKDINT_H = @HAVE_C_STDCKDINT_H@
+HAVE_C_UNREACHABLE = @HAVE_C_UNREACHABLE@
 HAVE_DECL_DIRFD = @HAVE_DECL_DIRFD@
 HAVE_DECL_ECVT = @HAVE_DECL_ECVT@
 HAVE_DECL_ENVIRON = @HAVE_DECL_ENVIRON@
@@ -911,6 +914,7 @@ HAVE_SIGNED_WINT_T = @HAVE_SIGNED_WINT_T@
 HAVE_SIGSET_T = @HAVE_SIGSET_T@
 HAVE_SLEEP = @HAVE_SLEEP@
 HAVE_SPAWN_H = @HAVE_SPAWN_H@
+HAVE_STDCKDINT_H = @HAVE_STDCKDINT_H@
 HAVE_STDINT_H = @HAVE_STDINT_H@
 HAVE_STPCPY = @HAVE_STPCPY@
 HAVE_STPNCPY = @HAVE_STPNCPY@
@@ -960,6 +964,8 @@ HAVE_VASPRINTF = @HAVE_VASPRINTF@
 HAVE_VDPRINTF = @HAVE_VDPRINTF@
 HAVE_WCHAR_H = @HAVE_WCHAR_H@
 HAVE_WINSOCK2_H = @HAVE_WINSOCK2_H@
+HAVE_WORKING_CXX_STDCKDINT_H = @HAVE_WORKING_CXX_STDCKDINT_H@
+HAVE_WORKING_C_STDCKDINT_H = @HAVE_WORKING_C_STDCKDINT_H@
 HAVE_XSERVER = @HAVE_XSERVER@
 HAVE__EXIT = @HAVE__EXIT@
 IEEE754_H = @IEEE754_H@
@@ -1087,6 +1093,7 @@ NEXT_AS_FIRST_DIRECTIVE_GETOPT_H = @NEXT_AS_FIRST_DIRECTIVE_GETOPT_H@
 NEXT_AS_FIRST_DIRECTIVE_INTTYPES_H = @NEXT_AS_FIRST_DIRECTIVE_INTTYPES_H@
 NEXT_AS_FIRST_DIRECTIVE_LIMITS_H = @NEXT_AS_FIRST_DIRECTIVE_LIMITS_H@
 NEXT_AS_FIRST_DIRECTIVE_SIGNAL_H = @NEXT_AS_FIRST_DIRECTIVE_SIGNAL_H@
+NEXT_AS_FIRST_DIRECTIVE_STDCKDINT_H = @NEXT_AS_FIRST_DIRECTIVE_STDCKDINT_H@
 NEXT_AS_FIRST_DIRECTIVE_STDDEF_H = @NEXT_AS_FIRST_DIRECTIVE_STDDEF_H@
 NEXT_AS_FIRST_DIRECTIVE_STDINT_H = @NEXT_AS_FIRST_DIRECTIVE_STDINT_H@
 NEXT_AS_FIRST_DIRECTIVE_STDIO_H = @NEXT_AS_FIRST_DIRECTIVE_STDIO_H@
@@ -1107,6 +1114,7 @@ NEXT_GETOPT_H = @NEXT_GETOPT_H@
 NEXT_INTTYPES_H = @NEXT_INTTYPES_H@
 NEXT_LIMITS_H = @NEXT_LIMITS_H@
 NEXT_SIGNAL_H = @NEXT_SIGNAL_H@
+NEXT_STDCKDINT_H = @NEXT_STDCKDINT_H@
 NEXT_STDDEF_H = @NEXT_STDDEF_H@
 NEXT_STDINT_H = @NEXT_STDINT_H@
 NEXT_STDIO_H = @NEXT_STDIO_H@
@@ -3202,6 +3210,15 @@ BUILT_SOURCES += $(STDCKDINT_H)
 ifneq (,$(GL_GENERATE_STDCKDINT_H_CONDITION))
 stdckdint.h: stdckdint.in.h $(top_builddir)/config.status
         $(gl_V_at)$(SED_HEADER_STDOUT) \
+              -e 's|@''GUARD_PREFIX''@|GL|g' \
+              -e 's|@''INCLUDE_NEXT''@|$(INCLUDE_NEXT)|g' \
+              -e 's|@''PRAGMA_SYSTEM_HEADER''@|@PRAGMA_SYSTEM_HEADER@|g' \
+              -e 's|@''PRAGMA_COLUMNS''@|@PRAGMA_COLUMNS@|g' \
+              -e 's|@''NEXT_STDCKDINT_H''@|$(NEXT_STDCKDINT_H)|g' \
+              -e 's|@''HAVE_C_STDCKDINT_H''@|$(HAVE_C_STDCKDINT_H)|g' \
+              -e 's|@''HAVE_WORKING_C_STDCKDINT_H''@|$(HAVE_WORKING_C_STDCKDINT_H)|g' \
+              -e 's|@''HAVE_CXX_STDCKDINT_H''@|$(HAVE_CXX_STDCKDINT_H)|g' \
+              -e 's|@''HAVE_WORKING_CXX_STDCKDINT_H''@|$(HAVE_WORKING_CXX_STDCKDINT_H)|g' \
           $(srcdir)/stdckdint.in.h > $@-t
         $(AM_V_at)mv $@-t $@
 else
@@ -3234,6 +3251,7 @@ stddef.h: stddef.in.h $(top_builddir)/config.status
               -e 's|@''STDDEF_NOT_IDEMPOTENT''@|$(STDDEF_NOT_IDEMPOTENT)|g' \
               -e 's|@''REPLACE_NULL''@|$(REPLACE_NULL)|g' \
               -e 's|@''HAVE_MAX_ALIGN_T''@|$(HAVE_MAX_ALIGN_T)|g' \
+              -e 's|@''HAVE_C_UNREACHABLE''@|$(HAVE_C_UNREACHABLE)|g' \
               $(srcdir)/stddef.in.h > $@-t
         $(AM_V_at)mv $@-t $@
 else
diff --git a/lib/open.c b/lib/open.c
index 7415b48f81c..8356c14f5b3 100644
--- a/lib/open.c
+++ b/lib/open.c
@@ -55,24 +55,25 @@ orig_open (const char *filename, int flags, mode_t mode)
 #include <sys/stat.h>
 #include <unistd.h>
 
+#ifndef OPEN_TRAILING_SLASH_BUG
+# define OPEN_TRAILING_SLASH_BUG false
+#endif
+
 #ifndef REPLACE_OPEN_DIRECTORY
-# define REPLACE_OPEN_DIRECTORY 0
+# define REPLACE_OPEN_DIRECTORY false
 #endif
 
+static int
+lstatif (char const *filename, struct stat *st, int flags)
+{
+  return flags & O_NOFOLLOW ? lstat (filename, st) : stat (filename, st);
+}
+
 int
 open (const char *filename, int flags, ...)
 {
-  /* 0 = unknown, 1 = yes, -1 = no.  */
-#if GNULIB_defined_O_CLOEXEC
-  int have_cloexec = -1;
-#else
-  static int have_cloexec;
-#endif
+  mode_t mode = 0;
 
-  mode_t mode;
-  int fd;
-
-  mode = 0;
   if (flags & O_CREAT)
     {
       va_list arg;
@@ -99,7 +100,6 @@ open (const char *filename, int flags, ...)
     filename = "NUL";
 #endif
 
-#if OPEN_TRAILING_SLASH_BUG
   /* Fail if one of O_CREAT, O_WRONLY, O_RDWR is specified and the filename
      ends in a slash, as POSIX says such a filename must name a directory
      <https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13>:
@@ -118,21 +118,55 @@ open (const char *filename, int flags, ...)
          directories,
        - if O_WRONLY or O_RDWR is specified, open() must fail because the
          file does not contain a '.' directory.  */
-  if ((flags & O_CREAT)
-      || (flags & O_ACCMODE) == O_RDWR
-      || (flags & O_ACCMODE) == O_WRONLY)
+  bool check_for_slash_bug;
+  if (OPEN_TRAILING_SLASH_BUG)
     {
       size_t len = strlen (filename);
-      if (len > 0 && filename[len - 1] == '/')
+      check_for_slash_bug = len && filename[len - 1] == '/';
+    }
+  else
+    check_for_slash_bug = false;
+
+  if (check_for_slash_bug
+      && (flags & O_CREAT
+          || (flags & O_ACCMODE) == O_RDWR
+          || (flags & O_ACCMODE) == O_WRONLY))
+    {
+      errno = EISDIR;
+      return -1;
+    }
+
+  /* With the trailing slash bug or without working O_DIRECTORY, check with
+     stat first lest we hang trying to open a fifo.  Although there is
+     a race between this and opening the file, we can do no better.
+     After opening the file we will check again with fstat.  */
+  bool check_directory =
+    (check_for_slash_bug
+     || (!HAVE_WORKING_O_DIRECTORY && flags & O_DIRECTORY));
+  if (check_directory)
+    {
+      struct stat statbuf;
+      if (lstatif (filename, &statbuf, flags) < 0)
         {
-          errno = EISDIR;
+          if (! (flags & O_CREAT && errno == ENOENT))
+            return -1;
+        }
+      else if (!S_ISDIR (statbuf.st_mode))
+        {
+          errno = ENOTDIR;
           return -1;
         }
     }
+
+  /* 0 = unknown, 1 = yes, -1 = no.  */
+#if GNULIB_defined_O_CLOEXEC
+  int have_cloexec = -1;
+#else
+  static int have_cloexec;
 #endif
 
-  fd = orig_open (filename,
-                  flags & ~(have_cloexec < 0 ? O_CLOEXEC : 0), mode);
+  int fd = orig_open (filename,
+                      flags & ~(have_cloexec < 0 ? O_CLOEXEC : 0), mode);
 
   if (flags & O_CLOEXEC)
     {
@@ -154,19 +188,21 @@ open (const char *filename, int flags, ...)
 #if REPLACE_FCHDIR
   /* Implementing fchdir and fdopendir requires the ability to open a
      directory file descriptor.  If open doesn't support that (as on
-     mingw), we use a dummy file that behaves the same as directories
+     mingw), use a dummy file that behaves the same as directories
      on Linux (ie. always reports EOF on attempts to read()), and
-     override fstat() in fchdir.c to hide the fact that we have a
-     dummy.  */
+     override fstat in fchdir.c to hide the dummy.  */
   if (REPLACE_OPEN_DIRECTORY && fd < 0 && errno == EACCES
-      && ((flags & O_ACCMODE) == O_RDONLY
-          || (O_SEARCH != O_RDONLY && (flags & O_ACCMODE) == O_SEARCH)))
+      && ((flags & (O_ACCMODE | O_CREAT)) == O_RDONLY
+          || (O_SEARCH != O_RDONLY
+              && (flags & (O_ACCMODE | O_CREAT)) == O_SEARCH)))
     {
       struct stat statbuf;
-      if (stat (filename, &statbuf) == 0 && S_ISDIR (statbuf.st_mode))
+      if (check_directory
+          || (lstatif (filename, &statbuf, flags) == 0
+              && S_ISDIR (statbuf.st_mode)))
         {
           /* Maximum recursion depth of 1.  */
-          fd = open ("/dev/null", flags, mode);
+          fd = open ("/dev/null", flags & ~O_DIRECTORY, mode);
           if (0 <= fd)
             fd = _gl_register_fd (fd, filename);
         }
@@ -175,10 +211,8 @@ open (const char *filename, int flags, ...)
     }
 #endif
 
-#if OPEN_TRAILING_SLASH_BUG
-  /* If the filename ends in a slash and fd does not refer to a directory,
-     then fail.
-     Rationale: POSIX says such a filename must name a directory
+  /* If checking for directories, fail if fd does not refer to a directory.
+     Rationale: A filename ending in slash cannot name a non-directory
      <https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13>:
        "A pathname that contains at least one non-<slash> character and that
         ends with one or more trailing <slash> characters shall not be resolved
@@ -186,23 +220,18 @@ open (const char *filename, int flags, ...)
         <slash> characters names an existing directory"
      If the named file without the slash is not a directory, open() must fail
      with ENOTDIR.  */
-  if (fd >= 0)
+  if (check_directory && 0 <= fd)
     {
-      /* We know len is positive, since open did not fail with ENOENT.  */
-      size_t len = strlen (filename);
-      if (filename[len - 1] == '/')
+      struct stat statbuf;
+      int r = fstat (fd, &statbuf);
+      if (r < 0 || !S_ISDIR (statbuf.st_mode))
         {
-          struct stat statbuf;
-
-          if (fstat (fd, &statbuf) >= 0 && !S_ISDIR (statbuf.st_mode))
-            {
-              close (fd);
-              errno = ENOTDIR;
-              return -1;
-            }
+          int err = r < 0 ? errno : ENOTDIR;
+          close (fd);
+          errno = err;
+          return -1;
         }
     }
-#endif
 
 #if REPLACE_FCHDIR
   if (!REPLACE_OPEN_DIRECTORY && 0 <= fd)
diff --git a/lib/qcopy-acl.c b/lib/qcopy-acl.c
index ad7966152aa..282f4b2d2a5 100644
--- a/lib/qcopy-acl.c
+++ b/lib/qcopy-acl.c
@@ -26,6 +26,7 @@
 #if USE_XATTR
 
 # include <attr/libattr.h>
+# include <dirent.h>
 # include <string.h>
 
 # if HAVE_LINUX_XATTR_H
@@ -61,6 +62,7 @@ is_attr_permissions (const char *name, struct error_context *ctx)
    a valid file descriptor, use file descriptor operations, else use
    filename based operations on SRC_NAME. Likewise for DEST_DESC and
    DST_NAME.
+   MODE should be the source file's st_mode.
    If access control lists are not available, fchmod the target file to
    MODE.  Also sets the non-permission bits of the destination file
    (S_ISUID, S_ISGID, S_ISVTX) to those from MODE if any are set.
@@ -86,10 +88,29 @@ qcopy_acl (const char *src_name, int source_desc, const char *dst_name,
      Functions attr_copy_* return 0 in case we copied something OR nothing
      to copy */
   if (ret == 0)
-    ret = source_desc <= 0 || dest_desc <= 0
-      ? attr_copy_file (src_name, dst_name, is_attr_permissions, NULL)
-      : attr_copy_fd (src_name, source_desc, dst_name, dest_desc,
-                      is_attr_permissions, NULL);
+    {
+      ret = source_desc <= 0 || dest_desc <= 0
+        ? attr_copy_file (src_name, dst_name, is_attr_permissions, NULL)
+        : attr_copy_fd (src_name, source_desc, dst_name, dest_desc,
+                        is_attr_permissions, NULL);
+
+      /* Copying can fail with EOPNOTSUPP even when the source
+         permissions are trivial (Bug#78328).  Don't report an error
+         in this case, as the chmod_or_fchmod suffices.  */
+      if (ret < 0 && errno == EOPNOTSUPP)
+        {
+          /* fdfile_has_aclinfo cares only about DT_DIR, _GL_DT_NOTDIR,
+             and DT_LNK (but DT_LNK is not possible here),
+             so use _GL_DT_NOTDIR | DT_UNKNOWN for other file types.  */
+          int flags = S_ISDIR (mode) ? DT_DIR : _GL_DT_NOTDIR | DT_UNKNOWN;
+
+          struct aclinfo ai;
+          if (!fdfile_has_aclinfo (source_desc, src_name, &ai, flags))
+            ret = 0;
+          aclinfo_free (&ai);
+          errno = EOPNOTSUPP;
+        }
+    }
 #else
   /* no XATTR, so we proceed the old dusty way */
   struct permission_context ctx;
diff --git a/lib/regcomp.c b/lib/regcomp.c
index a23f289d7a1..878b65baf07 100644
--- a/lib/regcomp.c
+++ b/lib/regcomp.c
@@ -1001,21 +1001,25 @@ create_initial_state (re_dfa_t *dfa)
             Idx dest_idx = dfa->edests[node_idx].elems[0];
             if (!re_node_set_contains (&init_nodes, dest_idx))
               {
-                reg_errcode_t merge_err
+                err
                   = re_node_set_merge (&init_nodes, dfa->eclosures + dest_idx);
-                if (merge_err != REG_NOERROR)
-                  return merge_err;
+                if (err != REG_NOERROR)
+                  break;
                 i = 0;
               }
           }
       }
 
   /* It must be the first time to invoke acquire_state.  */
-  dfa->init_state = re_acquire_state_context (&err, dfa, &init_nodes, 0);
-  /* We don't check ERR here, since the initial state must not be NULL.  */
+  dfa->init_state
+    = (err == REG_NOERROR
+       ? re_acquire_state_context (&err, dfa, &init_nodes, 0)
+       : NULL);
   if (__glibc_unlikely (dfa->init_state == NULL))
-    return err;
-  if (dfa->init_state->has_constraint)
+    {
+      /* Don't check ERR here, as the initial state must not be null.  */
+    }
+  else if (dfa->init_state->has_constraint)
     {
       dfa->init_state_word = re_acquire_state_context (&err, dfa, &init_nodes,
                                                        CONTEXT_WORD);
@@ -1025,17 +1029,13 @@ create_initial_state (re_dfa_t *dfa)
                                                          &init_nodes,
                                                          CONTEXT_NEWLINE
                                                          | CONTEXT_BEGBUF);
-      if (__glibc_unlikely (dfa->init_state_word == NULL
-                            || dfa->init_state_nl == NULL
-                            || dfa->init_state_begbuf == NULL))
-        return err;
     }
   else
     dfa->init_state_word = dfa->init_state_nl
       = dfa->init_state_begbuf = dfa->init_state;
 
   re_node_set_free (&init_nodes);
-  return REG_NOERROR;
+  return err;
 }
 
 /* If it is possible to do searching in single byte encoding instead of UTF-8
@@ -1677,12 +1677,11 @@ calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa, Idx node, bool root)
     {
       err = duplicate_node_closure (dfa, node, node, node,
                                     dfa->nodes[node].constraint);
-      if (__glibc_unlikely (err != REG_NOERROR))
-        return err;
     }
 
   /* Expand each epsilon destination nodes.  */
-  if (IS_EPSILON_NODE(dfa->nodes[node].type))
+  if (__glibc_likely (err == REG_NOERROR)
+      && IS_EPSILON_NODE (dfa->nodes[node].type))
     for (i = 0; i < dfa->edests[node].nelem; ++i)
       {
         re_node_set eclosure_elem;
@@ -1700,14 +1699,14 @@ calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa, Idx node, bool root)
           {
             err = calc_eclosure_iter (&eclosure_elem, dfa, edest, false);
             if (__glibc_unlikely (err != REG_NOERROR))
-              return err;
+              break;
           }
         else
           eclosure_elem = dfa->eclosures[edest];
         /* Merge the epsilon closure of 'edest'.  */
         err = re_node_set_merge (&eclosure, &eclosure_elem);
         if (__glibc_unlikely (err != REG_NOERROR))
-          return err;
+          break;
         /* If the epsilon closure of 'edest' is incomplete,
            the epsilon closure of this node is also incomplete.  */
         if (dfa->eclosures[edest].nelem == 0)
@@ -1717,12 +1716,18 @@ calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa, Idx node, bool root)
           }
       }
 
-  if (incomplete && !root)
-    dfa->eclosures[node].nelem = 0;
+  if (err != REG_NOERROR)
+    re_node_set_free (&eclosure);
   else
-    dfa->eclosures[node] = eclosure;
-  *new_set = eclosure;
-  return REG_NOERROR;
+    {
+      if (incomplete && !root)
+        dfa->eclosures[node].nelem = 0;
+      else
+        dfa->eclosures[node] = eclosure;
+      *new_set = eclosure;
+    }
+
+  return err;
 }
 
 /* Functions for token which are used in the parser.  */
@@ -3275,6 +3280,7 @@ parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa, re_token_t *token,
   else
     {
       free_charset (mbcset);
+      mbcset = NULL;
       /* Build a tree for simple bracket.  */
       br_token.type = SIMPLE_BRACKET;
       br_token.opr.sbcset = sbcset;
@@ -3288,7 +3294,8 @@ parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa, re_token_t *token,
   *err = REG_ESPACE;
  parse_bracket_exp_free_return:
   re_free (sbcset);
-  free_charset (mbcset);
+  if (__glibc_likely (mbcset != NULL))
+    free_charset (mbcset);
   return NULL;
 }
 
diff --git a/lib/regexec.c b/lib/regexec.c
index c5ab9b6649f..0d14ac35fe9 100644
--- a/lib/regexec.c
+++ b/lib/regexec.c
@@ -2271,7 +2271,7 @@ merge_state_with_log (reg_errcode_t *err, re_match_context_t *mctx,
          these destinations and the results of the transition table.  */
       pstate = mctx->state_log[cur_idx];
       log_nodes = pstate->entrance_nodes;
-      if (next_state != NULL)
+      if (next_state != NULL && next_state->entrance_nodes != NULL)
         {
           table_nodes = next_state->entrance_nodes;
           *err = re_node_set_init_union (&next_nodes, table_nodes,
diff --git a/lib/stat-time.h b/lib/stat-time.h
index 69813932d5e..38315b9f569 100644
--- a/lib/stat-time.h
+++ b/lib/stat-time.h
@@ -117,6 +117,31 @@ get_stat_birthtime_ns (_GL_UNUSED struct stat const *st)
 # endif
 }
 
+/* Constructs a 'struct timespec' with the given contents.
+   This macro / function is private to stat-time.h.  */
+#if !defined __cplusplus
+/* Use a C99 compound literal.
+   This is guaranteed to initialize also the padding bits, for example on
+   platforms where tv_sec is 64 bits and tv_nsec is 32 bits, thus avoiding
+   gcc -Wuse-of-uninitialized-value warnings.  */
+# define _gl_make_timespec(sec,nsec) \
+    (struct timespec) { .tv_sec = (sec), .tv_nsec = (nsec) }
+#else
+/* C++ does not have C99 compound literals.
+   A constructor invocation
+     timespec { (sec), (nsec) }
+   would make assumptions about the order of the fields of 'struct timespec',
+   which are not guaranteed by POSIX.  So, use an inline function.  */
+static inline struct timespec
+_gl_make_timespec (time_t sec, long nsec)
+{
+  struct timespec ts;
+  ts.tv_sec = sec;
+  ts.tv_nsec = nsec;
+  return ts;
+}
+#endif
+
 /* Return *ST's access time.  */
 _GL_STAT_TIME_INLINE struct timespec _GL_ATTRIBUTE_PURE
 get_stat_atime (struct stat const *st)
@@ -124,8 +149,7 @@ get_stat_atime (struct stat const *st)
 #ifdef STAT_TIMESPEC
   return STAT_TIMESPEC (st, st_atim);
 #else
-  return (struct timespec) { .tv_sec = st->st_atime,
-                             .tv_nsec = get_stat_atime_ns (st) };
+  return _gl_make_timespec (st->st_atime, get_stat_atime_ns (st));
 #endif
 }
 
@@ -136,8 +160,7 @@ get_stat_ctime (struct stat const *st)
 #ifdef STAT_TIMESPEC
   return STAT_TIMESPEC (st, st_ctim);
 #else
-  return (struct timespec) { .tv_sec = st->st_ctime,
-                             .tv_nsec = get_stat_ctime_ns (st) };
+  return _gl_make_timespec (st->st_ctime, get_stat_ctime_ns (st));
 #endif
 }
 
@@ -148,8 +171,7 @@ get_stat_mtime (struct stat const *st)
 #ifdef STAT_TIMESPEC
   return STAT_TIMESPEC (st, st_mtim);
 #else
-  return (struct timespec) { .tv_sec = st->st_mtime,
-                             .tv_nsec = get_stat_mtime_ns (st) };
+  return _gl_make_timespec (st->st_mtime, get_stat_mtime_ns (st));
 #endif
 }
 
@@ -164,8 +186,7 @@ get_stat_birthtime (_GL_UNUSED struct stat const *st)
      || defined HAVE_STRUCT_STAT_ST_BIRTHTIM_TV_NSEC)
   t = STAT_TIMESPEC (st, st_birthtim);
 #elif defined HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC
-  t = (struct timespec) { .tv_sec = st->st_birthtime,
-                          .tv_nsec = st->st_birthtimensec };
+  t = _gl_make_timespec (st->st_birthtime, st->st_birthtimensec);
 #elif defined _WIN32 && ! defined __CYGWIN__
   /* Native Windows platforms (but not Cygwin) put the "file creation
      time" in st_ctime (!).  See
@@ -173,11 +194,11 @@ get_stat_birthtime (_GL_UNUSED struct stat const *st)
 # if _GL_WINDOWS_STAT_TIMESPEC
   t = st->st_ctim;
 # else
-  t = (struct timespec) { .tv_sec = st->st_ctime };
+  t = _gl_make_timespec (st->st_ctime, 0);
 # endif
 #else
   /* Birth time is not supported.  */
-  t = (struct timespec) { .tv_sec = -1, .tv_nsec = -1 };
+  t = _gl_make_timespec (-1, -1);
 #endif
 
 #if (defined HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC \
@@ -189,7 +210,7 @@ get_stat_birthtime (_GL_UNUSED struct stat const *st)
      sometimes returns junk in the birth time fields; work around this
      bug if it is detected.  */
   if (! (t.tv_sec && 0 <= t.tv_nsec && t.tv_nsec < 1000000000))
-    t = (struct timespec) { .tv_sec = -1, .tv_nsec = -1 };
+    t = _gl_make_timespec (-1, -1);
 #endif
 
   return t;
diff --git a/lib/stdckdint.in.h b/lib/stdckdint.in.h
index 83277b728ee..bb9089b4a13 100644
--- a/lib/stdckdint.in.h
+++ b/lib/stdckdint.in.h
@@ -15,10 +15,30 @@
    You should have received a copy of the GNU Lesser General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
 
-#ifndef _GL_STDCKDINT_H
-#define _GL_STDCKDINT_H
+#if __GNUC__ >= 3
+@PRAGMA_SYSTEM_HEADER@
+#endif
+@PRAGMA_COLUMNS@
 
-#include "intprops-internal.h"
+#ifndef _@GUARD_PREFIX@_STDCKDINT_H
+
+/* The include_next requires a split double-inclusion guard.  */
+#if defined __cplusplus ? @HAVE_CXX_STDCKDINT_H@ : @HAVE_C_STDCKDINT_H@
+# @INCLUDE_NEXT@ @NEXT_STDCKDINT_H@
+#endif
+
+#ifndef _@GUARD_PREFIX@_STDCKDINT_H
+#define _@GUARD_PREFIX@_STDCKDINT_H
+
+/* Do nothing but include the system header if it works properly.  */
+# if defined __cplusplus ? !@HAVE_WORKING_CXX_STDCKDINT_H@ : !@HAVE_WORKING_C_STDCKDINT_H@
+
+/* Avoid redefining macros.  */
+#  undef ckd_add
+#  undef ckd_sub
+#  undef ckd_mul
+
+#  include "intprops-internal.h"
 
 /* Store into *R the low-order bits of A + B, A - B, A * B, respectively.
    Return 1 if the result overflows, 0 otherwise.
@@ -26,10 +46,13 @@
    bit-precise integer type, or an enumeration type.
 
    These are like the standard macros introduced in C23, except that
-   arguments should not have side effects.  */
+   arguments should not have side effects.  The C++26 standard is
+   expected to add this header and it's macros.  */
 
-#define ckd_add(r, a, b) ((bool) _GL_INT_ADD_WRAPV (a, b, r))
-#define ckd_sub(r, a, b) ((bool) _GL_INT_SUBTRACT_WRAPV (a, b, r))
-#define ckd_mul(r, a, b) ((bool) _GL_INT_MULTIPLY_WRAPV (a, b, r))
+#  define ckd_add(r, a, b) ((bool) _GL_INT_ADD_WRAPV (a, b, r))
+#  define ckd_sub(r, a, b) ((bool) _GL_INT_SUBTRACT_WRAPV (a, b, r))
+#  define ckd_mul(r, a, b) ((bool) _GL_INT_MULTIPLY_WRAPV (a, b, r))
 
-#endif /* _GL_STDCKDINT_H */
+# endif /* defined __cplusplus ? @HAVE_WORKING_CXX_STDCKDINT_H@ : @HAVE_WORKING_C_STDCKDINT_H@ */
+#endif /* _@GUARD_PREFIX@_STDCKDINT_H */
+#endif /* _@GUARD_PREFIX@_STDCKDINT_H */
diff --git a/lib/stddef.in.h b/lib/stddef.in.h
index dc689b8df80..e8c55ff1cdc 100644
--- a/lib/stddef.in.h
+++ b/lib/stddef.in.h
@@ -188,38 +188,57 @@ typedef union
 #endif
 
 /* ISO C 23 § 7.21.1 The unreachable macro  */
-#ifndef unreachable
+/* This macro is only usable in C, not in C++.
+   There is no way to define it as a macro in C++, because that would break code
+   that does
+       #include <utility>
+       ... std::unreachable() ...
+   Similarly, there is no way to define it as an inline function in C++, because
+   that would break code that does
+       #include <utility>
+       using std::unreachable;
+   As a workaround, we define a macro gl_unreachable, that is like unreachable,
+   but is usable in both C and C++.  */
 
 /* Code borrowed from verify.h.  */
-# ifndef _GL_HAS_BUILTIN_UNREACHABLE
-#  if defined __clang_major__ && __clang_major__ < 5
-#   define _GL_HAS_BUILTIN_UNREACHABLE 0
-#  elif 4 < __GNUC__ + (5 <= __GNUC_MINOR__) && !defined __clang__
-#   define _GL_HAS_BUILTIN_UNREACHABLE 1
-#  elif defined __has_builtin
-#   define _GL_HAS_BUILTIN_UNREACHABLE __has_builtin (__builtin_unreachable)
-#  else
-#   define _GL_HAS_BUILTIN_UNREACHABLE 0
-#  endif
+#ifndef _GL_HAS_BUILTIN_UNREACHABLE
+# if defined __clang_major__ && __clang_major__ < 5
+#  define _GL_HAS_BUILTIN_UNREACHABLE 0
+# elif 4 < __GNUC__ + (5 <= __GNUC_MINOR__) && !defined __clang__
+#  define _GL_HAS_BUILTIN_UNREACHABLE 1
+# elif defined __has_builtin
+#  define _GL_HAS_BUILTIN_UNREACHABLE __has_builtin (__builtin_unreachable)
+# else
+#  define _GL_HAS_BUILTIN_UNREACHABLE 0
 # endif
+#endif
 
-# if _GL_HAS_BUILTIN_UNREACHABLE
-#  define unreachable() __builtin_unreachable ()
-# elif 1200 <= _MSC_VER
-#  define unreachable() __assume (0)
-# else
+#if _GL_HAS_BUILTIN_UNREACHABLE
+# define gl_unreachable() __builtin_unreachable ()
+#elif 1200 <= _MSC_VER
+# define gl_unreachable() __assume (0)
+#elif !defined __cplusplus && @HAVE_C_UNREACHABLE@
+# define gl_unreachable() unreachable ()
+#else
 /* Declare abort(), without including <stdlib.h>.  */
 extern
-#  if defined __cplusplus
+# if defined __cplusplus
 "C"
-#  endif
+# endif
 _Noreturn
 void abort (void)
-#  if defined __cplusplus && (__GLIBC__ >= 2)
+# if defined __cplusplus && (__GLIBC__ >= 2)
 _GL_ATTRIBUTE_NOTHROW
-#  endif
+# endif
 ;
-#  define unreachable() abort ()
+# define gl_unreachable() abort ()
+#endif
+
+#if !defined __cplusplus && !@HAVE_C_UNREACHABLE@
+/* In C, define unreachable as a macro.  */
+
+# ifndef unreachable
+#  define unreachable() gl_unreachable ()
 # endif
 
 #endif
diff --git a/lib/string.in.h b/lib/string.in.h
index e7642211685..e3d94b76c17 100644
--- a/lib/string.in.h
+++ b/lib/string.in.h
@@ -215,25 +215,49 @@ _GL_EXTERN_C void free (void *);
 /* Declarations for ISO C N3322.  */
 #if defined __GNUC__ && __GNUC__ >= 15 && !defined __clang__
 _GL_EXTERN_C void *memcpy (void *__dest, const void *__src, size_t __n)
+# if __GLIBC__ + (__GLIBC_MINOR__ >= 2) > 2
+  _GL_ATTRIBUTE_NOTHROW
+# endif
   _GL_ATTRIBUTE_NONNULL_IF_NONZERO (1, 3)
   _GL_ATTRIBUTE_NONNULL_IF_NONZERO (2, 3);
 _GL_EXTERN_C void *memccpy (void *__dest, const void *__src, int __c, size_t __n)
+# if __GLIBC__ + (__GLIBC_MINOR__ >= 2) > 2
+  _GL_ATTRIBUTE_NOTHROW
+# endif
   _GL_ATTRIBUTE_NONNULL_IF_NONZERO (1, 4)
   _GL_ATTRIBUTE_NONNULL_IF_NONZERO (2, 4);
 _GL_EXTERN_C void *memmove (void *__dest, const void *__src, size_t __n)
+# if __GLIBC__ + (__GLIBC_MINOR__ >= 2) > 2
+  _GL_ATTRIBUTE_NOTHROW
+# endif
   _GL_ATTRIBUTE_NONNULL_IF_NONZERO (1, 3)
   _GL_ATTRIBUTE_NONNULL_IF_NONZERO (2, 3);
 _GL_EXTERN_C char *strncpy (char *__dest, const char *__src, size_t __n)
+# if __GLIBC__ + (__GLIBC_MINOR__ >= 2) > 2
+  _GL_ATTRIBUTE_NOTHROW
+# endif
   _GL_ATTRIBUTE_NONNULL_IF_NONZERO (1, 3)
   _GL_ATTRIBUTE_NONNULL_IF_NONZERO (2, 3);
 _GL_EXTERN_C char *strndup (const char *__s, size_t __n)
+# if __GLIBC__ + (__GLIBC_MINOR__ >= 2) > 2
+  _GL_ATTRIBUTE_NOTHROW
+# endif
   _GL_ATTRIBUTE_NONNULL_IF_NONZERO (1, 2);
 _GL_EXTERN_C char *strncat (char *__dest, const char *__src, size_t __n)
+# if __GLIBC__ + (__GLIBC_MINOR__ >= 2) > 2
+  _GL_ATTRIBUTE_NOTHROW
+# endif
   _GL_ARG_NONNULL ((1)) _GL_ATTRIBUTE_NONNULL_IF_NONZERO (2, 3);
 _GL_EXTERN_C int memcmp (const void *__s1, const void *__s2, size_t __n)
+# if __GLIBC__ + (__GLIBC_MINOR__ >= 2) > 2
+  _GL_ATTRIBUTE_NOTHROW
+# endif
   _GL_ATTRIBUTE_NONNULL_IF_NONZERO (1, 3)
   _GL_ATTRIBUTE_NONNULL_IF_NONZERO (2, 3);
 _GL_EXTERN_C int strncmp (const char *__s1, const char *__s2, size_t __n)
+# if __GLIBC__ + (__GLIBC_MINOR__ >= 2) > 2
+  _GL_ATTRIBUTE_NOTHROW
+# endif
   _GL_ATTRIBUTE_NONNULL_IF_NONZERO (1, 3)
   _GL_ATTRIBUTE_NONNULL_IF_NONZERO (2, 3);
 # ifndef __cplusplus
@@ -243,6 +267,9 @@ _GL_EXTERN_C void *memrchr (const void *__s, int __c, size_t __n)
   _GL_ATTRIBUTE_NONNULL_IF_NONZERO (1, 3);
 # endif
 _GL_EXTERN_C void *memset (void *__s, int __c, size_t __n)
+# if __GLIBC__ + (__GLIBC_MINOR__ >= 2) > 2
+  _GL_ATTRIBUTE_NOTHROW
+# endif
   _GL_ATTRIBUTE_NONNULL_IF_NONZERO (1, 3);
 _GL_EXTERN_C void *memset_explicit (void *__s, int __c, size_t __n)
   _GL_ATTRIBUTE_NONNULL_IF_NONZERO (1, 3);
diff --git a/lib/sys_stat.in.h b/lib/sys_stat.in.h
index 8bde5a7d631..c3c38fd653e 100644
--- a/lib/sys_stat.in.h
+++ b/lib/sys_stat.in.h
@@ -849,7 +849,11 @@ _GL_WARN_ON_USE (mknodat, "mknodat is not portable - "
 #   elif @WINDOWS_64_BIT_ST_SIZE@
      /* Above, we define stat to _stati64.  */
 #    if defined __MINGW32__ && defined _stati64
-#     ifndef _USE_32BIT_TIME_T
+#     ifdef _USE_32BIT_TIME_T
+       /* The system headers possibly 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)
diff --git a/lib/unistd.in.h b/lib/unistd.in.h
index c135a770dc1..9f057d30cdf 100644
--- a/lib/unistd.in.h
+++ b/lib/unistd.in.h
@@ -95,6 +95,15 @@
 # include <stdio.h>
 #endif
 
+/* Native Windows platforms declare _chdir, _getcwd, _rmdir in
+   <io.h> and/or <direct.h>, not in <unistd.h>.
+   They also declare _access(), _chmod(), _close(), _dup(), _dup2(), _isatty(),
+   _lseek(), _read(), _unlink(), _write() in <io.h>.  */
+#if defined _WIN32 && !defined __CYGWIN__
+# include <io.h>
+# include <direct.h>
+#endif
+
 /* FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Solaris 11.4, and glibc 2.41
    do not define O_CLOEXEC in <unistd.h>.  */
 /* Cygwin 1.7.1 and Android 4.3 declare unlinkat in <fcntl.h>, not in
@@ -120,15 +129,6 @@
 # undef __need_system_stdlib_h
 #endif
 
-/* Native Windows platforms declare _chdir, _getcwd, _rmdir in
-   <io.h> and/or <direct.h>, not in <unistd.h>.
-   They also declare _access(), _chmod(), _close(), _dup(), _dup2(), _isatty(),
-   _lseek(), _read(), _unlink(), _write() in <io.h>.  */
-#if defined _WIN32 && !defined __CYGWIN__
-# include <io.h>
-# include <direct.h>
-#endif
-
 /* Native Windows platforms declare _execl*, _execv* in <process.h>.  */
 #if defined _WIN32 && !defined __CYGWIN__
 # include <process.h>