192 files changed, 637 insertions, 844 deletions
diff --git a/gl/m4/00gnulib.m4 b/gl/m4/00gnulib.m4
index 2b205b35..a4b32403 100644
--- a/gl/m4/00gnulib.m4
+++ b/gl/m4/00gnulib.m4
@@ -1,6 +1,6 @@
 # 00gnulib.m4
 # serial 9
-dnl Copyright (C) 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2009-2026 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.
diff --git a/gl/m4/__inline.m4 b/gl/m4/__inline.m4
index d1b8257b..4dedc0d4 100644
--- a/gl/m4/__inline.m4
+++ b/gl/m4/__inline.m4
@@ -1,6 +1,6 @@
 # __inline.m4
 # serial 1
-dnl Copyright 2017-2025 Free Software Foundation, Inc.
+dnl Copyright 2017-2026 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.
diff --git a/gl/m4/absolute-header.m4 b/gl/m4/absolute-header.m4
index 5501b07b..94ecc510 100644
--- a/gl/m4/absolute-header.m4
+++ b/gl/m4/absolute-header.m4
@@ -1,6 +1,6 @@
 # absolute-header.m4
 # serial 18
-dnl Copyright (C) 2006-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2006-2026 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.
diff --git a/gl/m4/af_alg.m4 b/gl/m4/af_alg.m4
index 38575b6d..e4ff9a3d 100644
--- a/gl/m4/af_alg.m4
+++ b/gl/m4/af_alg.m4
@@ -1,6 +1,6 @@
 # af_alg.m4
 # serial 6
-dnl Copyright 2018-2025 Free Software Foundation, Inc.
+dnl Copyright 2018-2026 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.
diff --git a/gl/m4/alloca.m4 b/gl/m4/alloca.m4
index 68fc6211..ff0c59dd 100644
--- a/gl/m4/alloca.m4
+++ b/gl/m4/alloca.m4
@@ -1,6 +1,6 @@
 # alloca.m4
 # serial 21
-dnl Copyright (C) 2002-2004, 2006-2007, 2009-2025 Free Software Foundation,
+dnl Copyright (C) 2002-2004, 2006-2007, 2009-2026 Free Software Foundation,
 dnl Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
diff --git a/gl/m4/arpa_inet_h.m4 b/gl/m4/arpa_inet_h.m4
index 5dae6f72..63634c30 100644
--- a/gl/m4/arpa_inet_h.m4
+++ b/gl/m4/arpa_inet_h.m4
@@ -1,6 +1,6 @@
 # arpa_inet_h.m4
 # serial 18
-dnl Copyright (C) 2006, 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2006, 2008-2026 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.
diff --git a/gl/m4/assert_h.m4 b/gl/m4/assert_h.m4
index e77524ca..d9433ef7 100644
--- a/gl/m4/assert_h.m4
+++ b/gl/m4/assert_h.m4
@@ -1,6 +1,6 @@
 # assert_h.m4
-# serial 5
+# serial 6
-dnl Copyright (C) 2011-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2011-2026 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.
@@ -56,8 +56,6 @@ AC_DEFUN([gl_ASSERT_H],
  dnl The seemingly redundant parentheses are necessary for MSVC 14.
  dnl #undef assert so that programs are not tempted to use it without
  dnl specifically including assert.h.
-  dnl #undef __ASSERT_H__ so that on IRIX, when programs later include
-  dnl <assert.h>, this include actually defines assert.
  dnl Break the #undef_s apart with a comment so that 'configure' does
  dnl not comment them out.
  AH_VERBATIM([zzstatic_assert],
@@ -78,9 +76,6 @@ AC_DEFUN([gl_ASSERT_H],
             && __GNUG__ < 6 && __clang_major__ < 6)))
 #include <assert.h>
 #undef/**/assert
- #ifdef __sgi
-  #undef/**/__ASSERT_H__
- #endif
 /* Solaris 11.4 <assert.h> defines static_assert as a macro with 2 arguments.
    We need it also to be invocable with a single argument.
    Haiku 2022 <assert.h> does not define static_assert at all.  */
diff --git a/gl/m4/base64.m4 b/gl/m4/base64.m4
index 785d31c0..40beb50b 100644
--- a/gl/m4/base64.m4
+++ b/gl/m4/base64.m4
@@ -1,6 +1,6 @@
 # base64.m4
 # serial 4
-dnl Copyright (C) 2004, 2006, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2004, 2006, 2009-2026 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.
diff --git a/gl/m4/btowc.m4 b/gl/m4/btowc.m4
index 59d52be6..93c9d769 100644
--- a/gl/m4/btowc.m4
+++ b/gl/m4/btowc.m4
@@ -1,6 +1,6 @@
 # btowc.m4
-# serial 15
+# serial 16
-dnl Copyright (C) 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2008-2026 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.
@@ -13,7 +13,7 @@ AC_DEFUN([gl_FUNC_BTOWC],
  dnl Check whether <wchar.h> is usable at all, first. Otherwise the test
  dnl program below may lead to an endless loop. See
-  dnl <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42440>.
+  dnl <https://gcc.gnu.org/PR42440>.
  AC_REQUIRE([gl_WCHAR_H_INLINE_OK])
  AC_CHECK_FUNCS_ONCE([btowc])
@@ -54,43 +54,6 @@ changequote([,])dnl
          ])
      ])
-    dnl IRIX 6.5 btowc(EOF) is 0xFF, not WEOF.
-    AC_CACHE_CHECK([whether btowc(EOF) is correct],
-      [gl_cv_func_btowc_eof],
-      [
-        dnl Initial guess, used when cross-compiling or when no suitable locale
-        dnl is present.
-changequote(,)dnl
-        case "$host_os" in
-                             # Guess no on IRIX.
-          irix*)             gl_cv_func_btowc_eof="guessing no" ;;
-                             # Guess yes on native Windows.
-          mingw* | windows*) gl_cv_func_btowc_eof="guessing yes" ;;
-                             # Guess yes otherwise.
-          *)                 gl_cv_func_btowc_eof="guessing yes" ;;
-        esac
-changequote([,])dnl
-        if test $LOCALE_FR != none; then
-          AC_RUN_IFELSE(
-            [AC_LANG_SOURCE([[
-#include <locale.h>
-#include <stdio.h>
-#include <wchar.h>
-int main ()
-{
-  if (setlocale (LC_ALL, "$LOCALE_FR") != NULL)
-    {
-      if (btowc (EOF) != WEOF)
-        return 1;
-    }
-  return 0;
-}]])],
-            [gl_cv_func_btowc_eof=yes],
-            [gl_cv_func_btowc_eof=no],
-            [:])
-        fi
-      ])
    dnl On mingw, in the C locale, btowc is inconsistent with mbrtowc:
    dnl mbrtowc avoids calling MultiByteToWideChar when MB_CUR_MAX is 1 and
    dnl ___lc_codepage_func() is 0, but btowc is lacking this special case.
@@ -146,10 +109,6 @@ int main ()
      *yes) ;;
      *) REPLACE_BTOWC=1 ;;
    esac
-    case "$gl_cv_func_btowc_eof" in
-      *yes) ;;
-      *) REPLACE_BTOWC=1 ;;
-    esac
    case "$gl_cv_func_btowc_consistent" in
      *yes) ;;
      *) REPLACE_BTOWC=1 ;;
diff --git a/gl/m4/build-to-host.m4 b/gl/m4/build-to-host.m4
index 01bff8f3..d3b93ce1 100644
--- a/gl/m4/build-to-host.m4
+++ b/gl/m4/build-to-host.m4
@@ -1,6 +1,6 @@
 # build-to-host.m4
 # serial 5
-dnl Copyright (C) 2023-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2023-2026 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.
diff --git a/gl/m4/builtin-expect.m4 b/gl/m4/builtin-expect.m4
index 76d32867..cf96977e 100644
--- a/gl/m4/builtin-expect.m4
+++ b/gl/m4/builtin-expect.m4
@@ -1,6 +1,6 @@
 # builtin-expect.m4
 # serial 3
-dnl Copyright 2016-2025 Free Software Foundation, Inc.
+dnl Copyright 2016-2026 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.
diff --git a/gl/m4/byteswap.m4 b/gl/m4/byteswap.m4
index b53cb4d0..a0287062 100644
--- a/gl/m4/byteswap.m4
+++ b/gl/m4/byteswap.m4
@@ -1,6 +1,6 @@
 # byteswap.m4
 # serial 7
-dnl Copyright (C) 2005, 2007, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2005, 2007, 2009-2026 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.
diff --git a/gl/m4/c-bool.m4 b/gl/m4/c-bool.m4
index 8fa8bfc8..f04041a4 100644
--- a/gl/m4/c-bool.m4
+++ b/gl/m4/c-bool.m4
@@ -1,6 +1,6 @@
 # c-bool.m4
 # serial 3
-dnl Copyright 2022-2025 Free Software Foundation, Inc.
+dnl Copyright 2022-2026 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.
diff --git a/gl/m4/c32rtomb.m4 b/gl/m4/c32rtomb.m4
index ce26a31e..b7a0d44c 100644
--- a/gl/m4/c32rtomb.m4
+++ b/gl/m4/c32rtomb.m4
@@ -1,6 +1,6 @@
 # c32rtomb.m4
 # serial 8
-dnl Copyright (C) 2020-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2020-2026 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.
diff --git a/gl/m4/calloc.m4 b/gl/m4/calloc.m4
index ac7d08d4..2ed64332 100644
--- a/gl/m4/calloc.m4
+++ b/gl/m4/calloc.m4
@@ -1,6 +1,6 @@
 # calloc.m4
 # serial 36
-dnl Copyright (C) 2004-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2004-2026 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.
diff --git a/gl/m4/close.m4 b/gl/m4/close.m4
index 314e321e..9b498643 100644
--- a/gl/m4/close.m4
+++ b/gl/m4/close.m4
@@ -1,6 +1,6 @@
 # close.m4
 # serial 10
-dnl Copyright (C) 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2008-2026 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.
diff --git a/gl/m4/codeset.m4 b/gl/m4/codeset.m4
index 6bed9dee..4ab542f4 100644
--- a/gl/m4/codeset.m4
+++ b/gl/m4/codeset.m4
@@ -1,6 +1,6 @@
 # codeset.m4
 # serial 5 (gettext-0.18.2)
-dnl Copyright (C) 2000-2002, 2006, 2008-2014, 2016, 2019-2025 Free Software
+dnl Copyright (C) 2000-2002, 2006, 2008-2014, 2016, 2019-2026 Free Software
 dnl Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
diff --git a/gl/m4/double-slash-root.m4 b/gl/m4/double-slash-root.m4
index 5c40b73c..957adca6 100644
--- a/gl/m4/double-slash-root.m4
+++ b/gl/m4/double-slash-root.m4
@@ -1,6 +1,6 @@
 # double-slash-root.m4
 # serial 4   -*- Autoconf -*-
-dnl Copyright (C) 2006, 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2006, 2008-2026 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.
diff --git a/gl/m4/dup2.m4 b/gl/m4/dup2.m4
index 5da3a0b9..e1d51898 100644
--- a/gl/m4/dup2.m4
+++ b/gl/m4/dup2.m4
@@ -1,6 +1,6 @@
 # dup2.m4
 # serial 28
-dnl Copyright (C) 2002, 2005, 2007, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2002, 2005, 2007, 2009-2026 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.
diff --git a/gl/m4/environ.m4 b/gl/m4/environ.m4
index e0690e54..5c0644ab 100644
--- a/gl/m4/environ.m4
+++ b/gl/m4/environ.m4
@@ -1,6 +1,6 @@
 # environ.m4
 # serial 8
-dnl Copyright (C) 2001-2004, 2006-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2001-2004, 2006-2026 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.
diff --git a/gl/m4/errno_h.m4 b/gl/m4/errno_h.m4
index 420d5bb3..ade19b6f 100644
--- a/gl/m4/errno_h.m4
+++ b/gl/m4/errno_h.m4
@@ -1,6 +1,6 @@
 # errno_h.m4
-# serial 18
+# serial 19
-dnl Copyright (C) 2004, 2006, 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2004, 2006, 2008-2026 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.
@@ -83,59 +83,4 @@ booboo
    gl_NEXT_HEADERS([errno.h])
    GL_GENERATE_ERRNO_H=true
  fi
-  gl_REPLACE_ERRNO_VALUE([EMULTIHOP])
-  gl_REPLACE_ERRNO_VALUE([ENOLINK])
-  gl_REPLACE_ERRNO_VALUE([EOVERFLOW])
-])
-# Assuming $1 = EOVERFLOW.
-# The EOVERFLOW errno value ought to be defined in <errno.h>, according to
-# POSIX.  But some systems (like OpenBSD 4.0 or AIX 3) don't define it, and
-# some systems (like OSF/1) define it when _XOPEN_SOURCE_EXTENDED is defined.
-# Check for the value of EOVERFLOW.
-# Set the variables EOVERFLOW_HIDDEN and EOVERFLOW_VALUE.
-AC_DEFUN([gl_REPLACE_ERRNO_VALUE],
-[
-  if $GL_GENERATE_ERRNO_H; then
-    AC_CACHE_CHECK([for ]$1[ value], [gl_cv_header_errno_h_]$1, [
-      AC_EGREP_CPP([yes],[
-#include <errno.h>
-#ifdef ]$1[
-yes
-#endif
-      ],
-      [gl_cv_header_errno_h_]$1[=yes],
-      [gl_cv_header_errno_h_]$1[=no])
-      if test $gl_cv_header_errno_h_]$1[ = no; then
-        AC_EGREP_CPP([yes],[
-#define _XOPEN_SOURCE_EXTENDED 1
-#include <errno.h>
-#ifdef ]$1[
-yes
-#endif
-          ], [gl_cv_header_errno_h_]$1[=hidden])
-        if test $gl_cv_header_errno_h_]$1[ = hidden; then
-          dnl The macro exists but is hidden.
-          dnl Define it to the same value.
-          AC_COMPUTE_INT([gl_cv_header_errno_h_]$1, $1, [
-#define _XOPEN_SOURCE_EXTENDED 1
-#include <errno.h>
-/* The following two lines are a workaround against an autoconf-2.52 bug.  */
-#include <stdio.h>
-#include <stdlib.h>
-])
-        fi
-      fi
-    ])
-    case $gl_cv_header_errno_h_]$1[ in
-      yes | no)
-        ]$1[_HIDDEN=0; ]$1[_VALUE=
-        ;;
-      *)
-        ]$1[_HIDDEN=1; ]$1[_VALUE="$gl_cv_header_errno_h_]$1["
-        ;;
-    esac
-    AC_SUBST($1[_HIDDEN])
-    AC_SUBST($1[_VALUE])
-  fi
 ])
diff --git a/gl/m4/error.m4 b/gl/m4/error.m4
index 1572250a..f14b9ceb 100644
--- a/gl/m4/error.m4
+++ b/gl/m4/error.m4
@@ -1,6 +1,6 @@
 # error.m4
 # serial 16
-dnl Copyright (C) 1996-1998, 2001-2004, 2009-2025 Free Software Foundation,
+dnl Copyright (C) 1996-1998, 2001-2004, 2009-2026 Free Software Foundation,
 dnl Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
diff --git a/gl/m4/error_h.m4 b/gl/m4/error_h.m4
index 4ef5cbff..73e96943 100644
--- a/gl/m4/error_h.m4
+++ b/gl/m4/error_h.m4
@@ -1,6 +1,6 @@
 # error_h.m4
 # serial 5
-dnl Copyright (C) 1996-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 1996-2026 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.
diff --git a/gl/m4/exponentd.m4 b/gl/m4/exponentd.m4
index 08e93397..bff98570 100644
--- a/gl/m4/exponentd.m4
+++ b/gl/m4/exponentd.m4
@@ -1,6 +1,6 @@
 # exponentd.m4
 # serial 5
-dnl Copyright (C) 2007-2008, 2010-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007-2008, 2010-2026 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.
diff --git a/gl/m4/extensions-aix.m4 b/gl/m4/extensions-aix.m4
index 08b703b4..9036d7bb 100644
--- a/gl/m4/extensions-aix.m4
+++ b/gl/m4/extensions-aix.m4
@@ -1,6 +1,6 @@
 # extensions-aix.m4
 # serial 1
-dnl Copyright (C) 2024-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2024-2026 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.
diff --git a/gl/m4/extensions.m4 b/gl/m4/extensions.m4
index 76516bce..01a8e5f9 100644
--- a/gl/m4/extensions.m4
+++ b/gl/m4/extensions.m4
@@ -1,6 +1,6 @@
 # extensions.m4
 # serial 25  -*- Autoconf -*-
-dnl Copyright (C) 2003, 2006-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2003, 2006-2026 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.
diff --git a/gl/m4/extern-inline.m4 b/gl/m4/extern-inline.m4
index d4fe6d82..4ccc4a95 100644
--- a/gl/m4/extern-inline.m4
+++ b/gl/m4/extern-inline.m4
@@ -1,6 +1,6 @@
 # extern-inline.m4
-# serial 1
+# serial 2
-dnl Copyright 2012-2025 Free Software Foundation, Inc.
+dnl Copyright 2012-2026 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.
@@ -43,9 +43,11 @@ AC_DEFUN([gl_EXTERN_INLINE],
   functions or macros in standard C headers like <ctype.h>.  For example,
   if isdigit is mistakenly implemented via a static inline function,
   a program containing an extern inline function that calls isdigit
-   may not work since the C standard prohibits extern inline functions
+   may not work since C99 through C23 prohibit extern inline functions
-   from calling static functions (ISO C 99 section 6.7.4.(3).
+   from calling static functions (ISO C 23 § 6.7.5 ¶ 3)).
-   This bug is known to occur on:
+   Although a future C standard will likely relax this restriction
+   <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3622.txt>,
+   respect it for now.  This bug is known to occur on:
     OS X 10.8 and earlier; see:
     https://lists.gnu.org/r/bug-gnulib/2012-12/msg00023.html
@@ -112,8 +114,8 @@ AC_DEFUN([gl_EXTERN_INLINE],
   suppress bogus "no previous prototype for 'FOO'"
   and "no previous declaration for 'FOO'" diagnostics,
   when FOO is an inline function in the header; see
-   <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54113> and
+   <https://gcc.gnu.org/PR54113> and
-   <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63877>.  */
+   <https://gcc.gnu.org/PR63877>.  */
 #if __GNUC__ == 4 && 6 <= __GNUC_MINOR__
 # if defined __GNUC_STDC_INLINE__ && __GNUC_STDC_INLINE__
 #  define _GL_INLINE_HEADER_CONST_PRAGMA
diff --git a/gl/m4/fclose.m4 b/gl/m4/fclose.m4
index cfb92e28..65eb7705 100644
--- a/gl/m4/fclose.m4
+++ b/gl/m4/fclose.m4
@@ -1,6 +1,6 @@
 # fclose.m4
 # serial 12
-dnl Copyright (C) 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2008-2026 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.
diff --git a/gl/m4/fcntl-o.m4 b/gl/m4/fcntl-o.m4
index 8020c481..a94fc557 100644
--- a/gl/m4/fcntl-o.m4
+++ b/gl/m4/fcntl-o.m4
@@ -1,6 +1,6 @@
 # fcntl-o.m4
 # serial 12
-dnl Copyright (C) 2006, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2006, 2009-2026 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.
diff --git a/gl/m4/fcntl.m4 b/gl/m4/fcntl.m4
index 08ab936f..69ac76f9 100644
--- a/gl/m4/fcntl.m4
+++ b/gl/m4/fcntl.m4
@@ -1,6 +1,6 @@
 # fcntl.m4
 # serial 12
-dnl Copyright (C) 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2009-2026 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.
diff --git a/gl/m4/fcntl_h.m4 b/gl/m4/fcntl_h.m4
index 1c9f9cce..946a0bd6 100644
--- a/gl/m4/fcntl_h.m4
+++ b/gl/m4/fcntl_h.m4
@@ -1,6 +1,6 @@
 # fcntl_h.m4
-# serial 20
+# serial 21
-dnl Copyright (C) 2006-2007, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2006-2007, 2009-2026 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.
@@ -26,7 +26,7 @@ AC_DEFUN_ONCE([gl_FCNTL_H],
  dnl corresponding gnulib module is not in use, if it is not common
  dnl enough to be declared everywhere.
  gl_WARN_ON_USE_PREPARE([[#include <fcntl.h>
-    ]], [fcntl openat])
+    ]], [fcntl openat openat2])
 ])
 # gl_FCNTL_MODULE_INDICATOR([modulename])
@@ -53,6 +53,7 @@ AC_DEFUN([gl_FCNTL_H_REQUIRE_DEFAULTS],
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_NONBLOCKING])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_OPEN])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_OPENAT])
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_OPENAT2])
    dnl Support Microsoft deprecated alias function names by default.
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_MDA_CREAT], [1])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_MDA_OPEN], [1])
@@ -66,6 +67,7 @@ AC_DEFUN([gl_FCNTL_H_DEFAULTS],
  dnl Assume proper GNU behavior unless another module says otherwise.
  HAVE_FCNTL=1;          AC_SUBST([HAVE_FCNTL])
  HAVE_OPENAT=1;         AC_SUBST([HAVE_OPENAT])
+  HAVE_OPENAT2=0;        AC_SUBST([HAVE_OPENAT2])
  REPLACE_CREAT=0;       AC_SUBST([REPLACE_CREAT])
  REPLACE_FCNTL=0;       AC_SUBST([REPLACE_FCNTL])
  REPLACE_OPEN=0;        AC_SUBST([REPLACE_OPEN])
diff --git a/gl/m4/fflush.m4 b/gl/m4/fflush.m4
index 399065b6..c5913b23 100644
--- a/gl/m4/fflush.m4
+++ b/gl/m4/fflush.m4
@@ -1,6 +1,6 @@
 # fflush.m4
 # serial 20
-dnl Copyright (C) 2007-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007-2026 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.
diff --git a/gl/m4/float_h.m4 b/gl/m4/float_h.m4
index 8580c9c9..c0ee7f8f 100644
--- a/gl/m4/float_h.m4
+++ b/gl/m4/float_h.m4
@@ -1,6 +1,6 @@
 # float_h.m4
-# serial 15
+# serial 17
-dnl Copyright (C) 2007, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007, 2009-2026 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.
@@ -13,7 +13,7 @@ AC_DEFUN([gl_FLOAT_H],
  GL_GENERATE_FLOAT_H=false
  REPLACE_FLOAT_LDBL=0
  case "$host_os" in
-    aix* | beos* | openbsd* | mirbsd* | irix*)
+    aix* | beos* | openbsd* | mirbsd*)
      GL_GENERATE_FLOAT_H=true
      ;;
    freebsd* | dragonfly*)
@@ -63,6 +63,7 @@ changequote([,])dnl
       [AC_LANG_PROGRAM(
          [[#include <float.h>
            int x[] = { FLT_DECIMAL_DIG, DBL_DECIMAL_DIG, LDBL_DECIMAL_DIG };
+            int y[] = { FLT_IS_IEC_60559, DBL_IS_IEC_60559, LDBL_IS_IEC_60559 };
            float maxf = FLT_NORM_MAX;
            double maxd = DBL_NORM_MAX;
            long double maxl = LDBL_NORM_MAX;
diff --git a/gl/m4/floorf.m4 b/gl/m4/floorf.m4
index cb75fce9..731f0b0a 100644
--- a/gl/m4/floorf.m4
+++ b/gl/m4/floorf.m4
@@ -1,6 +1,6 @@
 # floorf.m4
 # serial 21
-dnl Copyright (C) 2007, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007, 2009-2026 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.
diff --git a/gl/m4/fopen.m4 b/gl/m4/fopen.m4
index e27b3270..07779a16 100644
--- a/gl/m4/fopen.m4
+++ b/gl/m4/fopen.m4
@@ -1,6 +1,6 @@
 # fopen.m4
 # serial 16
-dnl Copyright (C) 2007-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007-2026 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.
diff --git a/gl/m4/fpurge.m4 b/gl/m4/fpurge.m4
index 408a2579..a7cf67dc 100644
--- a/gl/m4/fpurge.m4
+++ b/gl/m4/fpurge.m4
@@ -1,6 +1,6 @@
 # fpurge.m4
 # serial 16
-dnl Copyright (C) 2007, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007, 2009-2026 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.
diff --git a/gl/m4/freading.m4 b/gl/m4/freading.m4
index 373d2bff..b5b54f40 100644
--- a/gl/m4/freading.m4
+++ b/gl/m4/freading.m4
@@ -1,6 +1,6 @@
 # freading.m4
 # serial 3
-dnl Copyright (C) 2007, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007, 2009-2026 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.
diff --git a/gl/m4/free.m4 b/gl/m4/free.m4
index 485d8243..c7a134ba 100644
--- a/gl/m4/free.m4
+++ b/gl/m4/free.m4
@@ -1,6 +1,6 @@
 # free.m4
 # serial 6
-dnl Copyright (C) 2003-2005, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2003-2005, 2009-2026 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.
@@ -14,10 +14,10 @@ AC_DEFUN([gl_FUNC_FREE],
  dnl In the next release of POSIX, free must preserve errno.
  dnl https://www.austingroupbugs.net/view.php?id=385
-  dnl https://sourceware.org/bugzilla/show_bug.cgi?id=17924
+  dnl https://sourceware.org/PR17924
  dnl So far, we know of three platforms that do this:
  dnl * glibc >= 2.33, thanks to the fix for this bug:
-  dnl   <https://sourceware.org/bugzilla/show_bug.cgi?id=17924>
+  dnl   <https://sourceware.org/PR17924>
  dnl * OpenBSD >= 4.5, thanks to this commit:
  dnl   <https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/lib/libc/stdlib/malloc.c.diff?r1=1.100&r2=1.101&f=h>
  dnl * Solaris, because its malloc() implementation is based on brk(),
diff --git a/gl/m4/fseek.m4 b/gl/m4/fseek.m4
index ce728f60..398fd5f8 100644
--- a/gl/m4/fseek.m4
+++ b/gl/m4/fseek.m4
@@ -1,6 +1,6 @@
 # fseek.m4
 # serial 4
-dnl Copyright (C) 2007, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007, 2009-2026 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.
diff --git a/gl/m4/fseeko.m4 b/gl/m4/fseeko.m4
index c093d399..cd81961a 100644
--- a/gl/m4/fseeko.m4
+++ b/gl/m4/fseeko.m4
@@ -1,6 +1,6 @@
 # fseeko.m4
 # serial 21
-dnl Copyright (C) 2007-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007-2026 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.
diff --git a/gl/m4/fseterr.m4 b/gl/m4/fseterr.m4
index 3a94c288..e5ad635b 100644
--- a/gl/m4/fseterr.m4
+++ b/gl/m4/fseterr.m4
@@ -1,6 +1,6 @@
 # fseterr.m4
 # serial 2
-dnl Copyright (C) 2012-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2012-2026 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.
diff --git a/gl/m4/fstat.m4 b/gl/m4/fstat.m4
index e89bbc32..7db4e346 100644
--- a/gl/m4/fstat.m4
+++ b/gl/m4/fstat.m4
@@ -1,6 +1,6 @@
 # fstat.m4
 # serial 10
-dnl Copyright (C) 2011-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2011-2026 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.
diff --git a/gl/m4/fstypename.m4 b/gl/m4/fstypename.m4
index 4407b765..64122a73 100644
--- a/gl/m4/fstypename.m4
+++ b/gl/m4/fstypename.m4
@@ -1,6 +1,6 @@
 # fstypename.m4
 # serial 6
-dnl Copyright (C) 1998-1999, 2001, 2004, 2006, 2009-2025 Free Software
+dnl Copyright (C) 1998-1999, 2001, 2004, 2006, 2009-2026 Free Software
 dnl Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
diff --git a/gl/m4/fsusage.m4 b/gl/m4/fsusage.m4
index bb7b6e43..db6e0e3b 100644
--- a/gl/m4/fsusage.m4
+++ b/gl/m4/fsusage.m4
@@ -1,6 +1,6 @@
 # fsusage.m4
-# serial 35
+# serial 37
-dnl Copyright (C) 1997-1998, 2000-2001, 2003-2025 Free Software Foundation,
+dnl Copyright (C) 1997-1998, 2000-2001, 2003-2026 Free Software Foundation,
 dnl Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -48,16 +48,12 @@ AC_DEFUN([gl_FILE_SYSTEM_USAGE],
  # is what it gets when this test fails.
  if test $ac_fsusage_space = no; then
    # glibc/{Hurd,kFreeBSD}, FreeBSD >= 5.0, NetBSD >= 3.0,
-    # OpenBSD >= 4.4, AIX, HP-UX, IRIX, Solaris, Cygwin, Interix, BeOS.
+    # OpenBSD >= 4.4, AIX, HP-UX, Solaris, Cygwin, Interix, BeOS.
    AC_CACHE_CHECK([for statvfs function (SVR4)],
      [fu_cv_sys_stat_statvfs],
      [AC_LINK_IFELSE(
         [AC_LANG_PROGRAM([[
 #include <sys/types.h>
-#ifdef __osf__
-"Do not use Tru64's statvfs implementation"
-#endif
 #include <sys/statvfs.h>
 struct statvfs fsd;
@@ -79,7 +75,7 @@ int check_f_blocks_size[sizeof fsd.f_blocks * CHAR_BIT <= 32 ? -1 : 1];
    if test $fu_cv_sys_stat_statvfs = yes; then
      ac_fsusage_space=yes
      # AIX >= 5.2 has statvfs64 that has a wider f_blocks field than statvfs.
-      # glibc, HP-UX, IRIX, Solaris have statvfs64 as well, but on these systems
+      # glibc, HP-UX, Solaris have statvfs64 as well, but on these systems
      # statvfs with large-file support is already equivalent to statvfs64.
      AC_CACHE_CHECK([whether to use statvfs64],
        [fu_cv_sys_stat_statvfs64],
@@ -141,37 +137,9 @@ int check_f_blocks_size[sizeof fsd.f_blocks * CHAR_BIT <= 32 ? -1 : 1];
  fi
  if test $ac_fsusage_space = no; then
-    # DEC Alpha running OSF/1
-    AC_CACHE_CHECK([for 3-argument statfs function (DEC OSF/1)],
-      [fu_cv_sys_stat_statfs3_osf1],
-      [AC_RUN_IFELSE([AC_LANG_SOURCE([[
-#include <sys/param.h>
-#include <sys/types.h>
-#include <sys/mount.h>
-  int
-  main ()
-  {
-    struct statfs fsd;
-    fsd.f_fsize = 0;
-    return statfs (".", &fsd, sizeof (struct statfs)) != 0;
-  }]])],
-         [fu_cv_sys_stat_statfs3_osf1=yes],
-         [fu_cv_sys_stat_statfs3_osf1=no],
-         [fu_cv_sys_stat_statfs3_osf1=no])
-      ])
-    if test $fu_cv_sys_stat_statfs3_osf1 = yes; then
-      ac_fsusage_space=yes
-      AC_DEFINE([STAT_STATFS3_OSF1], [1],
-        [Define if statfs takes 3 args.  (DEC Alpha running OSF/1)])
-    fi
-  fi
-  if test $ac_fsusage_space = no; then
    # glibc/Linux, Mac OS X, FreeBSD < 5.0, NetBSD < 3.0, OpenBSD < 4.4.
    # (glibc/{Hurd,kFreeBSD}, FreeBSD >= 5.0, NetBSD >= 3.0,
-    # OpenBSD >= 4.4, AIX, HP-UX, OSF/1, Cygwin already handled above.)
+    # OpenBSD >= 4.4, AIX, HP-UX, Cygwin already handled above.)
-    # (On IRIX you need to include <sys/statfs.h>, not only <sys/mount.h> and
-    # <sys/vfs.h>.)
    # (On Solaris, statfs has 4 arguments.)
    AC_CACHE_CHECK([for two-argument statfs with statfs.f_bsize member (AIX, 4.3BSD)],
      [fu_cv_sys_stat_statfs2_bsize],
@@ -225,13 +193,12 @@ int check_f_blocks_size[sizeof fsd.f_blocks * CHAR_BIT <= 32 ? -1 : 1];
    if test $fu_cv_sys_stat_statfs4 = yes; then
      ac_fsusage_space=yes
      AC_DEFINE([STAT_STATFS4], [1],
-        [Define if statfs takes 4 args.  (SVR3, old Irix)])
+        [Define if statfs takes 4 args.  (SVR3)])
    fi
  fi
  if test $ac_fsusage_space = no; then
    # 4.4BSD and older NetBSD
-    # (OSF/1 already handled above.)
    # (On AIX, you need to include <sys/statfs.h>, not only <sys/mount.h>.)
    # (On Solaris, statfs has 4 arguments and 'struct statfs' is not declared in
    # <sys/mount.h>.)
diff --git a/gl/m4/ftell.m4 b/gl/m4/ftell.m4
index d5610b70..0b389f86 100644
--- a/gl/m4/ftell.m4
+++ b/gl/m4/ftell.m4
@@ -1,6 +1,6 @@
 # ftell.m4
 # serial 3
-dnl Copyright (C) 2007, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007, 2009-2026 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.
diff --git a/gl/m4/ftello.m4 b/gl/m4/ftello.m4
index 35d30f98..ae0e884f 100644
--- a/gl/m4/ftello.m4
+++ b/gl/m4/ftello.m4
@@ -1,6 +1,6 @@
 # ftello.m4
 # serial 17
-dnl Copyright (C) 2007-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007-2026 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.
diff --git a/gl/m4/getaddrinfo.m4 b/gl/m4/getaddrinfo.m4
index 2931d526..8a63600b 100644
--- a/gl/m4/getaddrinfo.m4
+++ b/gl/m4/getaddrinfo.m4
@@ -1,6 +1,6 @@
 # getaddrinfo.m4
-# serial 38
+# serial 39
-dnl Copyright (C) 2004-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2004-2026 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.
@@ -90,7 +90,7 @@ int getaddrinfo (const char *, const char *, const struct addrinfo *, struct add
    fi
  fi
  if test $HAVE_GETADDRINFO != 0; then
-    AC_CACHE_CHECK([whether getaddrinfo supports AI_NUMERICSERV],
+    AC_CACHE_CHECK([whether getaddrinfo supports AI_NUMERICHOST and AI_NUMERICSERV],
      [gl_cv_func_getaddrinfo_works],
      [AC_RUN_IFELSE(
         [AC_LANG_PROGRAM([[
@@ -107,16 +107,30 @@ int getaddrinfo (const char *, const char *, const struct addrinfo *, struct add
 #include <stddef.h>
 #include <string.h>
            ]], [[
-              struct addrinfo hints;
+              int result = 0;
              struct addrinfo *ai;
-              memset (&hints, 0, sizeof (hints));
+              {
-              hints.ai_flags = AI_NUMERICSERV;
+                struct addrinfo hints;
-              return getaddrinfo ("www.gnu.org", "http", &hints, &ai) != EAI_NONAME;
+                memset (&hints, 0, sizeof (hints));
+                hints.ai_flags = AI_NUMERICHOST;
+                if (getaddrinfo ("www.gnu.org", "http", &hints, &ai) != EAI_NONAME)
+                  result |= 1;
+              }
+              {
+                struct addrinfo hints;
+                memset (&hints, 0, sizeof (hints));
+                hints.ai_flags = AI_NUMERICSERV;
+                if (getaddrinfo ("www.gnu.org", "http", &hints, &ai) != EAI_NONAME)
+                  result |= 2;
+              }
+              return result;
            ]])
         ],
         [gl_cv_func_getaddrinfo_works=yes],
         [gl_cv_func_getaddrinfo_works=no],
         [case "$host_os" in
+                               # Guess no on Solaris.
+            solaris*)          gl_cv_func_getaddrinfo_works="guessing no" ;;
                               # Guess no on native Windows.
            mingw* | windows*) gl_cv_func_getaddrinfo_works="guessing no" ;;
                               # Guess yes otherwise.
diff --git a/gl/m4/getdelim.m4 b/gl/m4/getdelim.m4
index 63d88306..8b6eff47 100644
--- a/gl/m4/getdelim.m4
+++ b/gl/m4/getdelim.m4
@@ -1,7 +1,7 @@
 # getdelim.m4
-# serial 19
+# serial 21
-dnl Copyright (C) 2005-2007, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2005-2007, 2009-2026 Free Software Foundation, Inc.
 dnl
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -37,6 +37,7 @@ AC_DEFUN([gl_FUNC_GETDELIM],
           gl_cv_func_working_getdelim=no ;;
         *)
           echo fooNbarN | tr -d '\012' | tr N '\012' > conftest.data
+           touch conftest.empty
           AC_RUN_IFELSE([AC_LANG_SOURCE([[
 #    include <stdio.h>
 #    include <stdlib.h>
@@ -44,6 +45,7 @@ AC_DEFUN([gl_FUNC_GETDELIM],
    int main ()
    {
      FILE *in = fopen ("./conftest.data", "r");
+      int result = 0;
      if (!in)
        return 1;
      {
@@ -53,7 +55,7 @@ AC_DEFUN([gl_FUNC_GETDELIM],
        size_t siz = 0;
        int len = getdelim (&line, &siz, '\n', in);
        if (!(len == 4 && line && strcmp (line, "foo\n") == 0))
-          { free (line); fclose (in); return 2; }
+          result |= 2;
        free (line);
      }
      {
@@ -62,35 +64,40 @@ AC_DEFUN([gl_FUNC_GETDELIM],
        char *line = NULL;
        size_t siz = (size_t)(~0) / 4;
        if (getdelim (&line, &siz, '\n', in) == -1)
-          { fclose (in); return 3; }
+          result |= 4;
        free (line);
      }
      fclose (in);
-      return 0;
+      {
+        /* Test that reading EOF as the first character sets the first byte
+           in the buffer to NUL.  This fails on glibc 2.42 and earlier.  */
+        in = fopen ("./conftest.empty", "r");
+        if (!in)
+          return 1;
+        char *line = malloc (1);
+        line[0] = 'A';
+        size_t siz = 1;
+        if (getdelim (&line, &siz, '\n', in) != -1 || line[0] != '\0')
+          result |= 8;
+        free (line);
+      }
+      fclose (in);
+      return result;
    }
    ]])],
             [gl_cv_func_working_getdelim=yes],
             [gl_cv_func_working_getdelim=no],
-             [dnl We're cross compiling.
+             [case "$host_os" in
-              dnl Guess it works on glibc2 systems and musl systems.
+                                    # Guess yes on musl.
-              AC_EGREP_CPP([Lucky GNU user],
+                *-musl* | midipix*) gl_cv_func_working_getdelim="guessing yes" ;;
-                [
+                                    # Guess no on glibc.
-#include <features.h>
+                *-gnu* | gnu*)      gl_cv_func_working_getdelim="guessing no" ;;
-#ifdef __GNU_LIBRARY__
+                *)                  gl_cv_func_working_getdelim="$gl_cross_guess_normal" ;;
- #if (__GLIBC__ >= 2) && !defined __UCLIBC__
+              esac
-  Lucky GNU user
- #endif
-#endif
-                ],
-                [gl_cv_func_working_getdelim="guessing yes"],
-                [case "$host_os" in
-                   *-musl* | midipix*) gl_cv_func_working_getdelim="guessing yes" ;;
-                   *)                  gl_cv_func_working_getdelim="$gl_cross_guess_normal" ;;
-                 esac
-                ])
             ])
           ;;
       esac
+       rm -f conftest.data conftest.empty
      ])
    case "$gl_cv_func_working_getdelim" in
      *yes) ;;
diff --git a/gl/m4/getdtablesize.m4 b/gl/m4/getdtablesize.m4
index 112c1c4d..0b780110 100644
--- a/gl/m4/getdtablesize.m4
+++ b/gl/m4/getdtablesize.m4
@@ -1,6 +1,6 @@
 # getdtablesize.m4
 # serial 8
-dnl Copyright (C) 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2008-2026 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.
diff --git a/gl/m4/gethostname.m4 b/gl/m4/gethostname.m4
index be71ff78..33293521 100644
--- a/gl/m4/gethostname.m4
+++ b/gl/m4/gethostname.m4
@@ -1,6 +1,6 @@
 # gethostname.m4
 # serial 16
-dnl Copyright (C) 2002, 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2002, 2008-2026 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.
diff --git a/gl/m4/getline.m4 b/gl/m4/getline.m4
index b97b8011..ed32fa10 100644
--- a/gl/m4/getline.m4
+++ b/gl/m4/getline.m4
@@ -1,7 +1,7 @@
 # getline.m4
-# serial 33
+# serial 35
-dnl Copyright (C) 1998-2003, 2005-2007, 2009-2025 Free Software Foundation,
+dnl Copyright (C) 1998-2003, 2005-2007, 2009-2026 Free Software Foundation,
 dnl Inc.
 dnl
 dnl This file is free software; the Free Software Foundation
@@ -31,6 +31,7 @@ AC_DEFUN([gl_FUNC_GETLINE],
    AC_CACHE_CHECK([for working getline function],
      [am_cv_func_working_getline],
      [echo fooNbarN | tr -d '\012' | tr N '\012' > conftest.data
+       touch conftest.empty
       AC_RUN_IFELSE([AC_LANG_SOURCE([[
 #    include <stdio.h>
 #    include <stdlib.h>
@@ -38,6 +39,7 @@ AC_DEFUN([gl_FUNC_GETLINE],
    int main ()
    {
      FILE *in = fopen ("./conftest.data", "r");
+      int result = 0;
      if (!in)
        return 1;
      {
@@ -47,7 +49,7 @@ AC_DEFUN([gl_FUNC_GETLINE],
        size_t siz = 0;
        int len = getline (&line, &siz, in);
        if (!(len == 4 && line && strcmp (line, "foo\n") == 0))
-          { free (line); fclose (in); return 2; }
+          result |= 2;
        free (line);
      }
      {
@@ -56,33 +58,38 @@ AC_DEFUN([gl_FUNC_GETLINE],
        char *line = NULL;
        size_t siz = (size_t)(~0) / 4;
        if (getline (&line, &siz, in) == -1)
-          { fclose (in); return 3; }
+          result |= 4;
        free (line);
      }
      fclose (in);
-      return 0;
+      {
+        /* Test that reading EOF as the first character sets the first byte
+           in the buffer to NUL.  This fails on glibc 2.42 and earlier.  */
+        in = fopen ("./conftest.empty", "r");
+        if (!in)
+          return 1;
+        char *line = malloc (1);
+        line[0] = 'A';
+        size_t siz = 1;
+        if (getline (&line, &siz, in) != -1 || line[0] != '\0')
+          result |= 8;
+        free (line);
+      }
+      fclose (in);
+      return result;
    }
    ]])],
         [am_cv_func_working_getline=yes],
         [am_cv_func_working_getline=no],
-         [dnl We're cross compiling.
+         [case "$host_os" in
-          dnl Guess it works on glibc2 systems and musl systems.
+                                # Guess yes on musl.
-          AC_EGREP_CPP([Lucky GNU user],
+            *-musl* | midipix*) am_cv_func_working_getline="guessing yes" ;;
-            [
+                                # Guess no on glibc.
-#include <features.h>
+            *-gnu* | gnu*)      am_cv_func_working_getline="guessing no" ;;
-#ifdef __GNU_LIBRARY__
+            *)                  am_cv_func_working_getline="$gl_cross_guess_normal" ;;
- #if (__GLIBC__ >= 2) && !defined __UCLIBC__
+          esac
-  Lucky GNU user
- #endif
-#endif
-            ],
-            [am_cv_func_working_getline="guessing yes"],
-            [case "$host_os" in
-               *-musl* | midipix*) am_cv_func_working_getline="guessing yes" ;;
-               *)                  am_cv_func_working_getline="$gl_cross_guess_normal" ;;
-             esac
-            ])
         ])
+       rm -f conftest.data conftest.empty
      ])
  else
    am_cv_func_working_getline=no
diff --git a/gl/m4/getloadavg.m4 b/gl/m4/getloadavg.m4
index 8ab613db..dc226168 100644
--- a/gl/m4/getloadavg.m4
+++ b/gl/m4/getloadavg.m4
@@ -1,6 +1,6 @@
 # getloadavg.m4
-# serial 13
+# serial 14
-dnl Copyright (C) 1992-1996, 1999-2000, 2002-2003, 2006, 2008-2025 Free
+dnl Copyright (C) 1992-1996, 1999-2000, 2002-2003, 2006, 2008-2026 Free
 dnl Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -124,8 +124,7 @@ if test $gl_func_getloadavg_done = no; then
 fi
 # We cannot check for <dwarf.h>, because Solaris 2 does not use dwarf (it
-# uses stabs), but it is still SVR4.  We cannot check for <elf.h> because
+# uses stabs), but it is still SVR4.
-# Irix 4.0.5F has the header but not the library.
 if test $gl_func_getloadavg_done = no && test "$ac_cv_lib_elf_elf_begin" = yes \
    && test "$ac_cv_lib_kvm_kvm_open" = yes; then
  gl_func_getloadavg_done=yes
diff --git a/gl/m4/getopt.m4 b/gl/m4/getopt.m4
index cb344c15..c620b2b7 100644
--- a/gl/m4/getopt.m4
+++ b/gl/m4/getopt.m4
@@ -1,6 +1,6 @@
 # getopt.m4
-# serial 50
+# serial 52
-dnl Copyright (C) 2002-2006, 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2002-2006, 2008-2026 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.
@@ -88,8 +88,8 @@ AC_DEFUN([gl_GETOPT_CHECK_HEADERS],
        dnl Merging these three different test programs into a single one
        dnl would require a reset mechanism. On BSD systems, it can be done
        dnl through 'optreset'; on some others (glibc), it can be done by
-        dnl setting 'optind' to 0; on others again (HP-UX, IRIX, OSF/1,
+        dnl setting 'optind' to 0; on others again (HP-UX, Solaris 9,
-        dnl Solaris 9, musl libc), there is no such mechanism.
+        dnl musl libc), there is no such mechanism.
        if test $cross_compiling = no; then
          dnl Sanity check. Succeeds everywhere (except on MSVC,
          dnl which lacks <unistd.h> and getopt() entirely).
@@ -238,8 +238,7 @@ dnl is ambiguous with environment values that contain newlines.
             nocrash_init();
             /* This code succeeds on glibc 2.8, OpenBSD 4.0, Cygwin, mingw,
-                and fails on Mac OS X 10.5, AIX 5.2, HP-UX 11, IRIX 6.5,
+                and fails on Mac OS X 10.5, AIX 5.2, HP-UX 11, Solaris 10.  */
-                OSF/1 5.1, Solaris 10.  */
             {
               static char conftest[] = "conftest";
               static char plus[] = "-+";
@@ -250,7 +249,7 @@ dnl is ambiguous with environment values that contain newlines.
             }
             /* This code succeeds on glibc 2.8, mingw,
                and fails on Mac OS X 10.5, OpenBSD 4.0, AIX 5.2, HP-UX 11,
-                IRIX 6.5, OSF/1 5.1, Solaris 10, Cygwin 1.5.x.  */
+                Solaris 10, Cygwin 1.5.x.  */
             {
               static char program[] = "program";
               static char p[] = "-p";
diff --git a/gl/m4/getprogname.m4 b/gl/m4/getprogname.m4
index 90f34c74..d60f3efb 100644
--- a/gl/m4/getprogname.m4
+++ b/gl/m4/getprogname.m4
@@ -1,6 +1,6 @@
 # getprogname.m4
-# serial 8
+# serial 9
-dnl Copyright (C) 2016-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2016-2026 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.
@@ -12,6 +12,12 @@ AC_DEFUN([gl_FUNC_GETPROGNAME],
 [
  AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+  AC_CHECK_HEADERS_ONCE([sys/process.h])
+  if test $ac_cv_header_sys_process_h = yes; then
+    HAVE_SYS_PROCESS_H=1
+  else
+    HAVE_SYS_PROCESS_H=0
+  fi
  gl_CHECK_FUNCS_ANDROID([getprogname], [[#include <stdlib.h>]])
  if test $ac_cv_func_getprogname = no; then
    HAVE_GETPROGNAME=0
diff --git a/gl/m4/gettext_h.m4 b/gl/m4/gettext_h.m4
new file mode 100644
index 00000000..7ef89541
--- /dev/null
+++ b/gl/m4/gettext_h.m4
@@ -0,0 +1,21 @@
+# gettext_h.m4
+# serial 1
+dnl Copyright (C) 2025-2026 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+dnl This file is offered as-is, without any warranty.
+AC_DEFUN_ONCE([gl_GETTEXT_H],
+[
+  AC_SUBST([LIBINTL])
+  AC_SUBST([LTLIBINTL])
+  AH_BOTTOM([
+/* The text domainname for Gnulib messages.  Ordinarily this is "gnulib",
+   but packages that do their own translations of Gnulib can use something
+   different by defining GNULIB_TEXT_DOMAIN in their config.h file.  */
+#ifndef GNULIB_TEXT_DOMAIN
+# define GNULIB_TEXT_DOMAIN/**/"gnulib"
+#endif
+])
+])
diff --git a/gl/m4/gl-openssl.m4 b/gl/m4/gl-openssl.m4
index 3cfea50f..70f43a55 100644
--- a/gl/m4/gl-openssl.m4
+++ b/gl/m4/gl-openssl.m4
@@ -1,6 +1,6 @@
 # gl-openssl.m4
-# serial 7
+# serial 8
-dnl Copyright (C) 2013-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2013-2026 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -58,12 +58,17 @@ AC_DEFUN([gl_CRYPTO_CHECK],
    fi
    if test "x$with_openssl" != xauto-gpl-compat ||
       test "x$gl_cv_openssl_gpl_compat" = xyes; then
-      AC_CHECK_LIB([crypto], [$1],
+      m4_if([$1], [SHA3],
-        [AC_CHECK_HEADERS(
+        [AC_CHECK_LIB([crypto], [EVP_sha3_224],
-           m4_if([$1], [MD5], [openssl/md5.h], [openssl/sha.h]),
           [LIB_CRYPTO=-lcrypto
            AC_DEFINE([HAVE_OPENSSL_$1], [1],
-              [Define to 1 if libcrypto is used for $1.])])])
+              [Define to 1 if libcrypto is used for $1.])])],
+        [AC_CHECK_LIB([crypto], [$1],
+           [AC_CHECK_HEADERS(
+              m4_if([$1], [MD5], [openssl/md5.h], [openssl/sha.h]),
+              [LIB_CRYPTO=-lcrypto
+               AC_DEFINE([HAVE_OPENSSL_$1], [1],
+                 [Define to 1 if libcrypto is used for $1.])])])])
    fi
    if test "x$LIB_CRYPTO" = x; then
      message='openssl development library not found for $1.
diff --git a/gl/m4/gnulib-cache.m4 b/gl/m4/gnulib-cache.m4
index 6a6e8593..1b964b34 100644
--- a/gl/m4/gnulib-cache.m4
+++ b/gl/m4/gnulib-cache.m4
@@ -1,4 +1,4 @@
-# Copyright (C) 2002-2025 Free Software Foundation, Inc.
+# Copyright (C) 2002-2026 Free Software Foundation, Inc.
 #
 # This file is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
diff --git a/gl/m4/gnulib-common.m4 b/gl/m4/gnulib-common.m4
index 034dae69..26eef771 100644
--- a/gl/m4/gnulib-common.m4
+++ b/gl/m4/gnulib-common.m4
@@ -1,6 +1,6 @@
 # gnulib-common.m4
-# serial 113
+# serial 115
-dnl Copyright (C) 2007-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007-2026 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.
@@ -168,7 +168,7 @@ AC_DEFUN([gl_COMMON_BODY], [
      ======================================================================
      This gives a syntax error
        - in C mode with gcc
-          <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108796>, and
+          <https://gcc.gnu.org/PR108796>, and
        - in C++ mode with clang++ version < 16, and
        - in C++ mode, inside extern "C" {}, still in newer clang++ versions
          <https://github.com/llvm/llvm-project/issues/101990>.
@@ -414,22 +414,25 @@ AC_DEFUN([gl_COMMON_BODY], [
 #endif
 /* _GL_ATTRIBUTE_CONST declares:
-   It is OK for a compiler to move calls to the function and to omit
+   It is OK for a compiler to move a call, or omit a duplicate call
-   calls to the function if another call has the same arguments or the
+   and reuse a cached return value, even if the state changes between calls.
-   result is not used.
+   It is also OK to omit a call if the result is not used.
-   This attribute is safe for a function that neither depends on
+   This attribute is safe if the function does not change observable state,
-   nor affects state, and always returns exactly once -
+   returns a value determined solely by its arguments' values
+   without examining state, and always returns exactly once -
   e.g., does not raise an exception, call longjmp, or loop forever.
   (This attribute is stricter than _GL_ATTRIBUTE_PURE because the
-   function cannot observe state.  It is stricter than
+   function cannot observe state.  Unlike _GL_ATTRIBUTE_UNSEQUENCED
-   _GL_ATTRIBUTE_UNSEQUENCED because the function must return exactly
+   the function must return exactly once and cannot access state
-   once and cannot depend on state addressed by its arguments.)  */
+   addressed by its pointer arguments or that happens to have the same
+   value for all calls to the function, but the function is allowed to
+   return a pointer to storage that can be modified later.  */
 /* Applies to: functions.  */
 #ifndef _GL_ATTRIBUTE_CONST
 # if _GL_HAS_ATTRIBUTE (const)
 #  define _GL_ATTRIBUTE_CONST __attribute__ ((__const__))
 # else
-#  define _GL_ATTRIBUTE_CONST _GL_ATTRIBUTE_UNSEQUENCED
+#  define _GL_ATTRIBUTE_CONST
 # endif
 #endif
@@ -451,7 +454,7 @@ AC_DEFUN([gl_COMMON_BODY], [
   yet.  */
 #ifndef _GL_ATTRIBUTE_DEALLOC_FREE
 # if defined __cplusplus && defined __GNUC__ && !defined __clang__
-/* Work around GCC bug <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108231> */
+/* Work around GCC bug <https://gcc.gnu.org/PR108231> */
 #  define _GL_ATTRIBUTE_DEALLOC_FREE \
     _GL_ATTRIBUTE_DEALLOC ((void (*) (void *)) free, 1)
 # else
@@ -590,7 +593,9 @@ AC_DEFUN([gl_COMMON_BODY], [
 /* _GL_ATTRIBUTE_MAYBE_UNUSED declares that it is not a programming mistake if
   the entity is not used.  The compiler should not warn if the entity is not
-   used.  */
+   used.  However, 'int _GL_UNNAMED (i)' is preferable to
+   '_GL_ATTRIBUTE_MAYBE_UNUSED int i' when parameter I is unused
+   regardless of preprocessor macro settings.  */
 /* Applies to:
     - function, variable,
     - struct, union, struct/union member,
@@ -744,39 +749,40 @@ AC_DEFUN([gl_COMMON_BODY], [
 #endif
 /* _GL_ATTRIBUTE_PURE declares:
-   It is OK for a compiler to move calls to the function and to omit
+   It is OK for a compiler to move a call, or omit a duplicate call
-   calls to the function if another call has the same arguments or the
+   and reuse a cached return value, if observable state is the same.
-   result is not used, and if observable state is the same.
+   It is also OK to omit a call if the return value is not used.
-   This attribute is safe for a function that does not affect observable state
+   This attribute is safe if the function does not change observable state,
-   and always returns exactly once.
+   returns a value determined solely by its arguments's values
+   together with observable state, and always returns exactly once.
   (This attribute is looser than _GL_ATTRIBUTE_CONST because the function
-   can depend on observable state.  It is stricter than
+   can depend on observable state.
-   _GL_ATTRIBUTE_REPRODUCIBLE because the function must return exactly
+   Unlike _GL_ATTRIBUTE_REPRODUCIBLE the function must return exactly
-   once and cannot affect state addressed by its arguments.)  */
+   once and cannot change state addressed by its arguments, but the
+   function can return a pointer to storage whose contents change later.)  */
 /* Applies to: functions.  */
 #ifndef _GL_ATTRIBUTE_PURE
 # if _GL_HAS_ATTRIBUTE (pure)
 #  define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__))
 # else
-#  define _GL_ATTRIBUTE_PURE _GL_ATTRIBUTE_REPRODUCIBLE
+#  define _GL_ATTRIBUTE_PURE
 # endif
 #endif
 /* _GL_ATTRIBUTE_REPRODUCIBLE declares:
-   It is OK for a compiler to move calls to the function and to omit duplicate
+   It is OK for a compiler to move a call, or omit a duplicate call
-   calls to the function with the same arguments, so long as the state
+   and reuse a cached value returned either directly or indirectly via
-   addressed by its arguments is the same and is updated in time for
+   a pointer, if other observable state is the same;
-   the rest of the program.
+   however, pointer arguments cannot alias.
-   This attribute is safe for a function that is effectless and idempotent; see
+   This attribute is safe for a function that is effectless and idempotent;
-   ISO C 23 § 6.7.12.7 for a definition of these terms.
+   see ISO C 23 § 6.7.13.8 for a definition of these terms.
   (This attribute is looser than _GL_ATTRIBUTE_UNSEQUENCED because
-   the function need not be stateless and idempotent.  It is looser
+   the function need not be stateless or independent.
-   than _GL_ATTRIBUTE_PURE because the function need not return
+   Unlike _GL_ATTRIBUTE_PURE the function need not return exactly once
-   exactly once and can affect state addressed by its arguments.)
+   and can change state addressed by its pointer arguments, but the
+   function cannot return a pointer to storage whose contents change later.)
   See also <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2956.htm> and
-   <https://stackoverflow.com/questions/76847905/>.
+   <https://stackoverflow.com/questions/76847905/>.  */
-   ATTENTION! Efforts are underway to change the meaning of this attribute.
-   See <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3424.htm>.  */
 /* Applies to: functions, pointer to functions, function types.  */
 #ifndef _GL_ATTRIBUTE_REPRODUCIBLE
 /* This may be revisited when gcc and clang support [[reproducible]] or possibly
@@ -816,20 +822,22 @@ AC_DEFUN([gl_COMMON_BODY], [
 #endif
 /* _GL_ATTRIBUTE_UNSEQUENCED declares:
-   It is OK for a compiler to move calls to the function and to omit duplicate
+   It is OK for a compiler to move a call, or omit a duplicate call
-   calls to the function with the same arguments, so long as the state
+   and reuse a cached value returned either directly or indirectly via
-   addressed by its arguments is the same.
+   a pointer, if the state addressed by its pointer arguments is the same;
+   however, pointer arguments cannot alias.
   This attribute is safe for a function that is effectless, idempotent,
-   stateless, and independent; see ISO C 23 § 6.7.12.7 for a definition of
+   stateless, and independent; see ISO C 23 § 6.7.13.8 for a definition of
   these terms.
   (This attribute is stricter than _GL_ATTRIBUTE_REPRODUCIBLE because
-   the function must be stateless and independent.  It is looser than
+   the function must be stateless and independent.  Unlike
-   _GL_ATTRIBUTE_CONST because the function need not return exactly
+   _GL_ATTRIBUTE_CONST the function need not return exactly once, and
-   once and can depend on state addressed by its arguments.)
+   can depend on state accessed via its pointer arguments or that
+   happens to have the same value for all calls to the function, but
+   the function cannot return a pointer to storage whose contents
+   change later.)
   See also <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2956.htm> and
-   <https://stackoverflow.com/questions/76847905/>.
+   <https://stackoverflow.com/questions/76847905/>.  */
-   ATTENTION! Efforts are underway to change the meaning of this attribute.
-   See <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3424.htm>.  */
 /* Applies to: functions, pointer to functions, function types.  */
 #ifndef _GL_ATTRIBUTE_UNSEQUENCED
 /* This may be revisited when gcc and clang support [[unsequenced]] or possibly
@@ -869,6 +877,21 @@ AC_DEFUN([gl_COMMON_BODY], [
 # endif
 #endif
+/* _GL_UNNAMED (ID) is the "name" of an unnamed function parameter.
+   Each of the function's unnamed parameters should have a unique "name".
+   The "name" cannot be used.  This ports both to C17 and earlier, which
+   lack unnamed parameters, and to C++ and later C, which have them.  */
+/* Applies to:
+     - function parameters.  */
+#ifndef _GL_UNNAMED
+# if ((defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) < 202311 \
+      && !defined __cplusplus)
+#  define _GL_UNNAMED(id) unnamed_##id _GL_ATTRIBUTE_UNUSED
+# else
+#  define _GL_UNNAMED(id)
+# endif
+#endif
 /* The following attributes enable detection of multithread-safety problems
   and resource leaks at compile-time, by clang ≥ 15, when the warning option
   -Wthread-safety is enabled.  For usage, see
@@ -1406,7 +1429,7 @@ AC_DEFUN([gl_CC_GNULIB_WARNINGS],
    dnl -Wno-type-limits                      >= 4.3          >= 3.9
    dnl -Wno-undef                            >= 3            >= 3.9
    dnl -Wno-unsuffixed-float-constants       >= 4.5
-    dnl -Wno-unused-const-variable            >= 4.4          >= 3.9
+    dnl -Wno-unused-const-variable            >= 6.1          >= 3.9
    dnl -Wno-unused-function                  >= 3            >= 3.9
    dnl -Wno-unused-parameter                 >= 3            >= 3.9
    dnl
@@ -1436,7 +1459,7 @@ AC_DEFUN([gl_CC_GNULIB_WARNINGS],
      -Wno-sign-conversion
      -Wno-type-limits
      #endif
-      #if (__GNUC__ + (__GNUC_MINOR__ >= 4) > 4 && !defined __clang__) || (__clang_major__ + (__clang_minor__ >= 9) > 3)
+      #if (__GNUC__ + (__GNUC_MINOR__ >= 1) > 6 && !defined __clang__) || (__clang_major__ + (__clang_minor__ >= 9) > 3)
      -Wno-unused-const-variable
      #endif
      #if (__GNUC__ + (__GNUC_MINOR__ >= 5) > 4 && !defined __clang__)
diff --git a/gl/m4/gnulib-comp.m4 b/gl/m4/gnulib-comp.m4
index 50e98454..cdd46759 100644
--- a/gl/m4/gnulib-comp.m4
+++ b/gl/m4/gnulib-comp.m4
@@ -1,5 +1,5 @@
 # DO NOT EDIT! GENERATED AUTOMATICALLY!
-# Copyright (C) 2002-2025 Free Software Foundation, Inc.
+# Copyright (C) 2002-2026 Free Software Foundation, Inc.
 #
 # This file is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -209,6 +209,7 @@ AC_DEFUN([gl_EARLY],
  # Code from module stdint-h:
  # Code from module stdio-h:
  gl_STDIO_H_EARLY
+  # Code from module stdio-windows:
  # Code from module stdlib-h:
  # Code from module strcase:
  # Code from module strcasecmp:
@@ -218,6 +219,7 @@ AC_DEFUN([gl_EARLY],
  # Code from module strerror:
  # Code from module strerror-override:
  # Code from module string-h:
+  # Code from module stringeq:
  # Code from module strings-h:
  # Code from module strncasecmp:
  # Code from module strncpy:
@@ -570,7 +572,8 @@ AC_DEFUN([gl_INIT],
  ])
  gl_UNISTD_MODULE_INDICATOR([getdtablesize])
  gl_FUNC_GETHOSTNAME
-  gl_CONDITIONAL([GL_COND_OBJ_GETHOSTNAME], [test $HAVE_GETHOSTNAME = 0])
+  gl_CONDITIONAL([GL_COND_OBJ_GETHOSTNAME],
+                 [test $HAVE_GETHOSTNAME = 0 || test $UNISTD_H_HAVE_WINSOCK2_H = 1])
  AM_COND_IF([GL_COND_OBJ_GETHOSTNAME], [
    gl_PREREQ_GETHOSTNAME
  ])
@@ -614,8 +617,7 @@ AC_DEFUN([gl_INIT],
    gl_PREREQ_GETPROGNAME
  ])
  gl_STDLIB_MODULE_INDICATOR([getprogname])
-  AC_SUBST([LIBINTL])
+  gl_GETTEXT_H
-  AC_SUBST([LTLIBINTL])
  AC_PROG_MKDIR_P
  GNULIB_I18N
  AC_REQUIRE([gl_FUNC_SETLOCALE_NULL])
@@ -884,19 +886,6 @@ AC_DEFUN([gl_INIT],
  gl_STDIO_H
  gl_STDIO_H_REQUIRE_DEFAULTS
  AC_PROG_MKDIR_P
-  USES_MSVCRT=0
-  case "$host_os" in
-    mingw* | windows*)
-      AC_EGREP_CPP([Special], [
-  #ifndef _UCRT
-   Special
-  #endif
-        ],
-        [USES_MSVCRT=1])
-      ;;
-  esac
-  gl_CONDITIONAL([GL_COND_OBJ_STDIO_CONSOLESAFE], [test $USES_MSVCRT = 1])
-  AC_CHECK_FUNCS([vasprintf])
  gl_CONDITIONAL([GL_COND_OBJ_STDIO_READ], [test $REPLACE_STDIO_READ_FUNCS = 1])
  gl_CONDITIONAL([GL_COND_OBJ_STDIO_WRITE], [test $REPLACE_STDIO_WRITE_FUNCS = 1])
  dnl No need to create extra modules for these functions. Everyone who uses
@@ -922,6 +911,20 @@ AC_DEFUN([gl_INIT],
  gl_STDIO_MODULE_INDICATOR([fputs])
  gl_STDIO_MODULE_INDICATOR([puts])
  gl_STDIO_MODULE_INDICATOR([fwrite])
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  USES_MSVCRT=0
+  case "$host_os" in
+    mingw* | windows*)
+      AC_EGREP_CPP([Special], [
+  #ifndef _UCRT
+   Special
+  #endif
+        ],
+        [USES_MSVCRT=1])
+      ;;
+  esac
+  gl_CONDITIONAL([GL_COND_OBJ_STDIO_CONSOLESAFE], [test $USES_MSVCRT = 1])
+  AC_CHECK_FUNCS([vasprintf])
  gl_STDLIB_H
  gl_STDLIB_H_REQUIRE_DEFAULTS
  AC_PROG_MKDIR_P
@@ -957,6 +960,9 @@ AC_DEFUN([gl_INIT],
  gl_STRING_H
  gl_STRING_H_REQUIRE_DEFAULTS
  AC_PROG_MKDIR_P
+  gl_FUNC_STREQ
+  gl_FUNC_MEMEQ
+  gl_STRING_MODULE_INDICATOR([stringeq])
  gl_STRINGS_H
  gl_STRINGS_H_REQUIRE_DEFAULTS
  AC_PROG_MKDIR_P
@@ -1021,35 +1027,35 @@ AC_DEFUN([gl_INIT],
  gl_UNICASE_H
  gl_UNICASE_H_REQUIRE_DEFAULTS
  AC_PROG_MKDIR_P
-  gl_LIBUNISTRING_MODULE([1.3], [unicase/tolower])
+  gl_LIBUNISTRING_MODULE([1.4], [unicase/tolower])
  gl_LIBUNISTRING_LIBHEADER([1.3], [unictype.h])
  gl_UNICTYPE_H
  gl_UNICTYPE_H_REQUIRE_DEFAULTS
  AC_PROG_MKDIR_P
  AC_REQUIRE([AC_C_INLINE])
-  gl_LIBUNISTRING_MODULE([1.3], [unictype/ctype-alnum])
+  gl_LIBUNISTRING_MODULE([1.4], [unictype/ctype-alnum])
  AC_REQUIRE([AC_C_INLINE])
-  gl_LIBUNISTRING_MODULE([1.3], [unictype/ctype-alpha])
+  gl_LIBUNISTRING_MODULE([1.4], [unictype/ctype-alpha])
  AC_REQUIRE([AC_C_INLINE])
-  gl_LIBUNISTRING_MODULE([0.9.8], [unictype/ctype-blank])
+  gl_LIBUNISTRING_MODULE([1.4], [unictype/ctype-blank])
  AC_REQUIRE([AC_C_INLINE])
-  gl_LIBUNISTRING_MODULE([0.9.8], [unictype/ctype-cntrl])
+  gl_LIBUNISTRING_MODULE([1.4], [unictype/ctype-cntrl])
  AC_REQUIRE([AC_C_INLINE])
-  gl_LIBUNISTRING_MODULE([0.9.8], [unictype/ctype-digit])
+  gl_LIBUNISTRING_MODULE([1.4], [unictype/ctype-digit])
  AC_REQUIRE([AC_C_INLINE])
-  gl_LIBUNISTRING_MODULE([1.3], [unictype/ctype-graph])
+  gl_LIBUNISTRING_MODULE([1.4], [unictype/ctype-graph])
  AC_REQUIRE([AC_C_INLINE])
-  gl_LIBUNISTRING_MODULE([1.3], [unictype/ctype-lower])
+  gl_LIBUNISTRING_MODULE([1.4], [unictype/ctype-lower])
  AC_REQUIRE([AC_C_INLINE])
-  gl_LIBUNISTRING_MODULE([1.3], [unictype/ctype-print])
+  gl_LIBUNISTRING_MODULE([1.4], [unictype/ctype-print])
  AC_REQUIRE([AC_C_INLINE])
-  gl_LIBUNISTRING_MODULE([1.3], [unictype/ctype-punct])
+  gl_LIBUNISTRING_MODULE([1.4], [unictype/ctype-punct])
  AC_REQUIRE([AC_C_INLINE])
-  gl_LIBUNISTRING_MODULE([0.9.8], [unictype/ctype-space])
+  gl_LIBUNISTRING_MODULE([1.4], [unictype/ctype-space])
  AC_REQUIRE([AC_C_INLINE])
-  gl_LIBUNISTRING_MODULE([1.3], [unictype/ctype-upper])
+  gl_LIBUNISTRING_MODULE([1.4], [unictype/ctype-upper])
  AC_REQUIRE([AC_C_INLINE])
-  gl_LIBUNISTRING_MODULE([0.9.8], [unictype/ctype-xdigit])
+  gl_LIBUNISTRING_MODULE([1.4], [unictype/ctype-xdigit])
  gl_LIBUNISTRING_LIBHEADER([1.2], [uninorm.h])
  gl_UNINORM_H
  gl_UNINORM_H_REQUIRE_DEFAULTS
@@ -1062,7 +1068,7 @@ AC_DEFUN([gl_INIT],
  gl_UNITYPES_H
  gl_LIBUNISTRING_LIBHEADER([0.9.11], [uniwidth.h])
  AC_PROG_MKDIR_P
-  gl_LIBUNISTRING_MODULE([1.3], [uniwidth/width])
+  gl_LIBUNISTRING_MODULE([1.4], [uniwidth/width])
  gl_FUNC_GLIBC_UNLOCKED_IO
  gl_FUNC_UNSETENV
  gl_CONDITIONAL([GL_COND_OBJ_UNSETENV],
@@ -1535,6 +1541,7 @@ AC_DEFUN([gl_FILE_LIST], [
  lib/strerror-override.c
  lib/strerror-override.h
  lib/strerror.c
+  lib/string.c
  lib/string.in.h
  lib/strings.in.h
  lib/stripslash.c
@@ -1677,6 +1684,7 @@ AC_DEFUN([gl_FILE_LIST], [
  m4/getloadavg.m4
  m4/getopt.m4
  m4/getprogname.m4
+  m4/gettext_h.m4
  m4/gl-openssl.m4
  m4/gnulib-common.m4
  m4/gnulib-i18n.m4
@@ -1773,6 +1781,7 @@ AC_DEFUN([gl_FILE_LIST], [
  m4/strcasestr.m4
  m4/strerror.m4
  m4/string_h.m4
+  m4/stringeq.m4
  m4/strings_h.m4
  m4/strncasecmp.m4
  m4/strncpy.m4
diff --git a/gl/m4/gnulib-i18n.m4 b/gl/m4/gnulib-i18n.m4
index 868043e7..9a389187 100644
--- a/gl/m4/gnulib-i18n.m4
+++ b/gl/m4/gnulib-i18n.m4
@@ -1,6 +1,6 @@
 # gnulib-i18n.m4
 # serial 1
-dnl Copyright (C) 2005-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2005-2026 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.
diff --git a/gl/m4/gnulib-tool.m4 b/gl/m4/gnulib-tool.m4
index 8634a6e9..83d1e701 100644
--- a/gl/m4/gnulib-tool.m4
+++ b/gl/m4/gnulib-tool.m4
@@ -1,6 +1,6 @@
 # gnulib-tool.m4
 # serial 5
-dnl Copyright (C) 2004-2005, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2004-2005, 2009-2026 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.
diff --git a/gl/m4/hostent.m4 b/gl/m4/hostent.m4
index 9278285c..0303ff80 100644
--- a/gl/m4/hostent.m4
+++ b/gl/m4/hostent.m4
@@ -1,6 +1,6 @@
 # hostent.m4
 # serial 5
-dnl Copyright (C) 2008, 2010-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2008, 2010-2026 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.
diff --git a/gl/m4/idpriv.m4 b/gl/m4/idpriv.m4
index 6e855e9a..a7091ad3 100644
--- a/gl/m4/idpriv.m4
+++ b/gl/m4/idpriv.m4
@@ -1,6 +1,6 @@
 # idpriv.m4
 # serial 1
-dnl Copyright (C) 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2009-2026 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.
diff --git a/gl/m4/include_next.m4 b/gl/m4/include_next.m4
index 80de991e..a19f2dfd 100644
--- a/gl/m4/include_next.m4
+++ b/gl/m4/include_next.m4
@@ -1,6 +1,6 @@
 # include_next.m4
 # serial 27
-dnl Copyright (C) 2006-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2006-2026 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.
diff --git a/gl/m4/inet_ntop.m4 b/gl/m4/inet_ntop.m4
index 693bd51b..62e7a575 100644
--- a/gl/m4/inet_ntop.m4
+++ b/gl/m4/inet_ntop.m4
@@ -1,6 +1,6 @@
 # inet_ntop.m4
-# serial 22
+# serial 23
-dnl Copyright (C) 2005-2006, 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2005-2006, 2008-2026 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.
@@ -19,6 +19,7 @@ AC_DEFUN([gl_FUNC_INET_NTOP],
  dnl Solaris 8..10 provide inet_ntop in libnsl instead.
  dnl Solaris 2.6..7 provide inet_ntop in libresolv instead.
  dnl Haiku provides it in -lnetwork.
+  dnl QNX provides it in -lsocket.
  dnl Native Windows provides it in -lws2_32 instead, with a declaration in
  dnl <ws2tcpip.h>, and it uses stdcall calling convention, not cdecl
  dnl (hence we cannot use AC_CHECK_FUNCS, AC_SEARCH_LIBS to find it).
@@ -39,7 +40,7 @@ AC_DEFUN([gl_FUNC_INET_NTOP],
    fi
  else
    gl_saved_LIBS=$LIBS
-    AC_SEARCH_LIBS([inet_ntop], [nsl resolv network], [],
+    AC_SEARCH_LIBS([inet_ntop], [nsl resolv network socket], [],
      [AC_CHECK_FUNCS([inet_ntop])
       if test $ac_cv_func_inet_ntop = no; then
         HAVE_INET_NTOP=0
diff --git a/gl/m4/inet_pton.m4 b/gl/m4/inet_pton.m4
index b6e59a25..150c3a07 100644
--- a/gl/m4/inet_pton.m4
+++ b/gl/m4/inet_pton.m4
@@ -1,6 +1,6 @@
 # inet_pton.m4
-# serial 20
+# serial 21
-dnl Copyright (C) 2006, 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2006, 2008-2026 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -19,6 +19,7 @@ AC_DEFUN([gl_FUNC_INET_PTON],
  dnl Solaris 8..10 provide inet_pton in libnsl instead.
  dnl Solaris 2.6..7 provide inet_pton in libresolv instead.
  dnl Haiku provides it in -lnetwork.
+  dnl QNX provides it in -lsocket.
  dnl Native Windows provides it in -lws2_32 instead, with a declaration in
  dnl <ws2tcpip.h>, and it uses stdcall calling convention, not cdecl
  dnl (hence we cannot use AC_CHECK_FUNCS, AC_SEARCH_LIBS to find it).
@@ -39,7 +40,7 @@ AC_DEFUN([gl_FUNC_INET_PTON],
    fi
  else
    gl_saved_LIBS=$LIBS
-    AC_SEARCH_LIBS([inet_pton], [nsl resolv network], [],
+    AC_SEARCH_LIBS([inet_pton], [nsl resolv network socket], [],
      [AC_CHECK_FUNCS([inet_pton])
       if test $ac_cv_func_inet_pton = no; then
         HAVE_INET_PTON=0
diff --git a/gl/m4/intmax_t.m4 b/gl/m4/intmax_t.m4
index c1df7b27..ad79536c 100644
--- a/gl/m4/intmax_t.m4
+++ b/gl/m4/intmax_t.m4
@@ -1,6 +1,6 @@
 # intmax_t.m4
 # serial 9
-dnl Copyright (C) 1997-2004, 2006-2007, 2009-2025 Free Software Foundation,
+dnl Copyright (C) 1997-2004, 2006-2007, 2009-2026 Free Software Foundation,
 dnl Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
diff --git a/gl/m4/inttypes.m4 b/gl/m4/inttypes.m4
index 63c82c61..ec17c237 100644
--- a/gl/m4/inttypes.m4
+++ b/gl/m4/inttypes.m4
@@ -1,6 +1,6 @@
 # inttypes.m4
 # serial 37
-dnl Copyright (C) 2006-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2006-2026 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.
diff --git a/gl/m4/inttypes_h.m4 b/gl/m4/inttypes_h.m4
index ad939a53..ed9e7033 100644
--- a/gl/m4/inttypes_h.m4
+++ b/gl/m4/inttypes_h.m4
@@ -1,6 +1,6 @@
 # inttypes_h.m4
 # serial 10
-dnl Copyright (C) 1997-2004, 2006, 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 1997-2004, 2006, 2008-2026 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.
diff --git a/gl/m4/iswblank.m4 b/gl/m4/iswblank.m4
index d06b16a2..2c301a97 100644
--- a/gl/m4/iswblank.m4
+++ b/gl/m4/iswblank.m4
@@ -1,6 +1,6 @@
 # iswblank.m4
 # serial 7
-dnl Copyright (C) 2011-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2011-2026 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.
diff --git a/gl/m4/iswctype.m4 b/gl/m4/iswctype.m4
index f5a3b760..3b179a76 100644
--- a/gl/m4/iswctype.m4
+++ b/gl/m4/iswctype.m4
@@ -1,6 +1,6 @@
 # iswctype.m4
 # serial 3
-dnl Copyright (C) 2011-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2011-2026 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.
diff --git a/gl/m4/iswdigit.m4 b/gl/m4/iswdigit.m4
index 4582f598..7fca8167 100644
--- a/gl/m4/iswdigit.m4
+++ b/gl/m4/iswdigit.m4
@@ -1,6 +1,6 @@
 # iswdigit.m4
 # serial 9
-dnl Copyright (C) 2020-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2020-2026 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.
diff --git a/gl/m4/iswpunct.m4 b/gl/m4/iswpunct.m4
index d8e8d712..be312d6c 100644
--- a/gl/m4/iswpunct.m4
+++ b/gl/m4/iswpunct.m4
@@ -1,6 +1,6 @@
 # iswpunct.m4
 # serial 2
-dnl Copyright (C) 2023-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2023-2026 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.
diff --git a/gl/m4/iswxdigit.m4 b/gl/m4/iswxdigit.m4
index 95226fc4..2cb8e873 100644
--- a/gl/m4/iswxdigit.m4
+++ b/gl/m4/iswxdigit.m4
@@ -1,6 +1,6 @@
 # iswxdigit.m4
 # serial 9
-dnl Copyright (C) 2020-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2020-2026 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.
diff --git a/gl/m4/langinfo_h.m4 b/gl/m4/langinfo_h.m4
index 69f936f0..3ed8d593 100644
--- a/gl/m4/langinfo_h.m4
+++ b/gl/m4/langinfo_h.m4
@@ -1,6 +1,6 @@
 # langinfo_h.m4
-# serial 13
+# serial 14
-dnl Copyright (C) 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2009-2026 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.
@@ -18,18 +18,15 @@ AC_DEFUN_ONCE([gl_LANGINFO_H],
  dnl Determine whether <langinfo.h> exists. It is missing on mingw and BeOS.
  HAVE_LANGINFO_CODESET=0
-  HAVE_LANGINFO_T_FMT_AMPM=0
  HAVE_LANGINFO_ALTMON=0
  HAVE_LANGINFO_ABALTMON=0
  HAVE_LANGINFO_ERA=0
-  HAVE_LANGINFO_YESEXPR=0
  AC_CHECK_HEADERS_ONCE([langinfo.h])
  if test $ac_cv_header_langinfo_h = yes; then
    HAVE_LANGINFO_H=1
    dnl Determine what <langinfo.h> defines.
    dnl CODESET is missing on OpenBSD 3.8.
    dnl ERA etc. are missing on OpenBSD 6.7.
-    dnl T_FMT_AMPM and YESEXPR, NOEXPR are missing on IRIX 5.3.
    dnl ALTMON_* are missing on glibc 2.26 and many other systems.
    dnl ABALTMON_* are missing on glibc 2.41 and many other systems.
    AC_CACHE_CHECK([whether langinfo.h defines CODESET],
@@ -44,18 +41,6 @@ int a = CODESET;
    if test $gl_cv_header_langinfo_codeset = yes; then
      HAVE_LANGINFO_CODESET=1
    fi
-    AC_CACHE_CHECK([whether langinfo.h defines T_FMT_AMPM],
-      [gl_cv_header_langinfo_t_fmt_ampm],
-      [AC_COMPILE_IFELSE(
-         [AC_LANG_PROGRAM([[#include <langinfo.h>
-int a = T_FMT_AMPM;
-]])],
-         [gl_cv_header_langinfo_t_fmt_ampm=yes],
-         [gl_cv_header_langinfo_t_fmt_ampm=no])
-      ])
-    if test $gl_cv_header_langinfo_t_fmt_ampm = yes; then
-      HAVE_LANGINFO_T_FMT_AMPM=1
-    fi
    AC_CACHE_CHECK([whether langinfo.h defines ALTMON_1],
      [gl_cv_header_langinfo_altmon],
      [AC_COMPILE_IFELSE(
@@ -92,28 +77,14 @@ int a = ERA;
    if test $gl_cv_header_langinfo_era = yes; then
      HAVE_LANGINFO_ERA=1
    fi
-    AC_CACHE_CHECK([whether langinfo.h defines YESEXPR],
-      [gl_cv_header_langinfo_yesexpr],
-      [AC_COMPILE_IFELSE(
-         [AC_LANG_PROGRAM([[#include <langinfo.h>
-int a = YESEXPR;
-]])],
-         [gl_cv_header_langinfo_yesexpr=yes],
-         [gl_cv_header_langinfo_yesexpr=no])
-      ])
-    if test $gl_cv_header_langinfo_yesexpr = yes; then
-      HAVE_LANGINFO_YESEXPR=1
-    fi
  else
    HAVE_LANGINFO_H=0
  fi
  AC_SUBST([HAVE_LANGINFO_H])
  AC_SUBST([HAVE_LANGINFO_CODESET])
-  AC_SUBST([HAVE_LANGINFO_T_FMT_AMPM])
  AC_SUBST([HAVE_LANGINFO_ALTMON])
  AC_SUBST([HAVE_LANGINFO_ABALTMON])
  AC_SUBST([HAVE_LANGINFO_ERA])
-  AC_SUBST([HAVE_LANGINFO_YESEXPR])
  dnl Check for declarations of anything we want to poison if the
  dnl corresponding gnulib module is not in use.
diff --git a/gl/m4/largefile.m4 b/gl/m4/largefile.m4
index b24f657d..3134f336 100644
--- a/gl/m4/largefile.m4
+++ b/gl/m4/largefile.m4
@@ -1,6 +1,6 @@
 # largefile.m4
-# serial 2
+# serial 4
-dnl Copyright 1992-1996, 1998-2025 Free Software Foundation, Inc.
+dnl Copyright 1992-1996, 1998-2026 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.
@@ -355,8 +355,7 @@ AC_DEFUN([gl_LARGEFILE],
    *)
      dnl Nothing to do on gnulib's side.
      dnl A 64-bit off_t is
-      dnl   - already the default on Mac OS X, FreeBSD, NetBSD, OpenBSD, IRIX,
+      dnl   - already the default on Mac OS X, FreeBSD, NetBSD, OpenBSD, Cygwin,
-      dnl     OSF/1, Cygwin,
      dnl   - enabled by _FILE_OFFSET_BITS=64 (ensured by AC_SYS_LARGEFILE) on
      dnl     glibc, HP-UX, Solaris,
      dnl   - enabled by _LARGE_FILES=1 (ensured by AC_SYS_LARGEFILE) on AIX,
diff --git a/gl/m4/libunistring-base.m4 b/gl/m4/libunistring-base.m4
index 9b5795ed..f2f144ac 100644
--- a/gl/m4/libunistring-base.m4
+++ b/gl/m4/libunistring-base.m4
@@ -1,6 +1,6 @@
 # libunistring-base.m4
 # serial 10
-dnl Copyright (C) 2010-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2010-2026 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.
diff --git a/gl/m4/limits-h.m4 b/gl/m4/limits-h.m4
index 202df492..048c8fab 100644
--- a/gl/m4/limits-h.m4
+++ b/gl/m4/limits-h.m4
@@ -1,6 +1,6 @@
 # limits-h.m4
 # serial 1
-dnl Copyright 2016-2025 Free Software Foundation, Inc.
+dnl Copyright 2016-2026 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.
diff --git a/gl/m4/localcharset.m4 b/gl/m4/localcharset.m4
index 374a48f1..8e2c2755 100644
--- a/gl/m4/localcharset.m4
+++ b/gl/m4/localcharset.m4
@@ -1,6 +1,6 @@
 # localcharset.m4
 # serial 8
-dnl Copyright (C) 2002, 2004, 2006, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2002, 2004, 2006, 2009-2026 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.
diff --git a/gl/m4/locale-en.m4 b/gl/m4/locale-en.m4
index 4151428a..f5e035f3 100644
--- a/gl/m4/locale-en.m4
+++ b/gl/m4/locale-en.m4
@@ -1,6 +1,6 @@
 # locale-en.m4
 # serial 1
-dnl Copyright (C) 2003-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2003-2026 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.
@@ -19,7 +19,7 @@ AC_DEFUN_ONCE([gt_LOCALE_EN_UTF8],
      *-musl* | midipix*)
        dnl On musl libc, all kinds of ll_CC.UTF-8 locales exist, even without
        dnl any locale file on disk. But they are effectively equivalent to the
-        dnl C.UTF-8 locale, except for locale categories (such as LC_MESSSAGES)
+        dnl C.UTF-8 locale, except for locale categories (such as LC_MESSAGES)
        dnl for which localizations (.mo files) have been installed.
        gt_cv_locale_en_utf8=en_US.UTF-8
        ;;
diff --git a/gl/m4/locale-fr.m4 b/gl/m4/locale-fr.m4
index f504d5b5..097cefa6 100644
--- a/gl/m4/locale-fr.m4
+++ b/gl/m4/locale-fr.m4
@@ -1,6 +1,6 @@
 # locale-fr.m4
-# serial 24
+# serial 25
-dnl Copyright (C) 2003, 2005-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2003, 2005-2026 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.
@@ -112,7 +112,7 @@ int main () {
            if (LC_ALL=fr_FR.ISO-8859-1 LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; then
              gt_cv_locale_fr=fr_FR.ISO-8859-1
            else
-              # Test for the AIX, OSF/1, FreeBSD, NetBSD, OpenBSD locale name.
+              # Test for the AIX, FreeBSD, NetBSD, OpenBSD locale name.
              if (LC_ALL=fr_FR.ISO8859-1 LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; then
                gt_cv_locale_fr=fr_FR.ISO8859-1
              else
@@ -156,7 +156,7 @@ AC_DEFUN_ONCE([gt_LOCALE_FR_UTF8],
      *-musl* | midipix*)
        dnl On musl libc, all kinds of ll_CC.UTF-8 locales exist, even without
        dnl any locale file on disk. But they are effectively equivalent to the
-        dnl C.UTF-8 locale, except for locale categories (such as LC_MESSSAGES)
+        dnl C.UTF-8 locale, except for locale categories (such as LC_MESSAGES)
        dnl for which localizations (.mo files) have been installed.
        gt_cv_locale_fr_utf8=fr_FR.UTF-8
        ;;
diff --git a/gl/m4/locale-ja.m4 b/gl/m4/locale-ja.m4
index 1c813b89..ee4309ed 100644
--- a/gl/m4/locale-ja.m4
+++ b/gl/m4/locale-ja.m4
@@ -1,6 +1,6 @@
 # locale-ja.m4
-# serial 19
+# serial 21
-dnl Copyright (C) 2003, 2005-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2003, 2005-2026 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.
@@ -112,11 +112,11 @@ int main ()
            if (LC_ALL=ja_JP.EUC-JP LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; then
              gt_cv_locale_ja=ja_JP.EUC-JP
            else
-              # Test for the HP-UX, OSF/1, NetBSD locale name.
+              # Test for the HP-UX, NetBSD locale name.
              if (LC_ALL=ja_JP.eucJP LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; then
                gt_cv_locale_ja=ja_JP.eucJP
              else
-                # Test for the IRIX, FreeBSD locale name.
+                # Test for the FreeBSD locale name.
                if (LC_ALL=ja_JP.EUC LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; then
                  gt_cv_locale_ja=ja_JP.EUC
                else
diff --git a/gl/m4/locale-zh.m4 b/gl/m4/locale-zh.m4
index 6f9374d2..98975bdd 100644
--- a/gl/m4/locale-zh.m4
+++ b/gl/m4/locale-zh.m4
@@ -1,6 +1,6 @@
 # locale-zh.m4
 # serial 20
-dnl Copyright (C) 2003, 2005-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2003, 2005-2026 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.
diff --git a/gl/m4/locale_h.m4 b/gl/m4/locale_h.m4
index e1afbc16..aeda9f9d 100644
--- a/gl/m4/locale_h.m4
+++ b/gl/m4/locale_h.m4
@@ -1,6 +1,6 @@
 # locale_h.m4
-# serial 37
+# serial 39
-dnl Copyright (C) 2007, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007, 2009-2026 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.
@@ -63,8 +63,8 @@ AC_DEFUN_ONCE([gl_LOCALE_H],
  dnl Check whether 'struct lconv' is complete.
  dnl Bionic libc's 'struct lconv' is just a dummy.
-  dnl On OpenBSD 4.9, HP-UX 11, IRIX 6.5, OSF/1 5.1, Solaris 9, Cygwin 1.5.x,
+  dnl On OpenBSD 4.9, HP-UX 11, Solaris 9, Cygwin 1.5.x, mingw, MSVC 9,
-  dnl mingw, MSVC 9, it lacks the int_p_* and int_n_* members.
+  dnl it lacks the int_p_* and int_n_* members.
  AC_CACHE_CHECK([whether struct lconv is properly defined],
    [gl_cv_sys_struct_lconv_ok],
    [AC_COMPILE_IFELSE(
diff --git a/gl/m4/localeconv.m4 b/gl/m4/localeconv.m4
index 55a669d0..9fa31de8 100644
--- a/gl/m4/localeconv.m4
+++ b/gl/m4/localeconv.m4
@@ -1,6 +1,6 @@
 # localeconv.m4
 # serial 3
-dnl Copyright (C) 2012-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2012-2026 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.
diff --git a/gl/m4/lock.m4 b/gl/m4/lock.m4
index b1d3f435..7058fb30 100644
--- a/gl/m4/lock.m4
+++ b/gl/m4/lock.m4
@@ -1,6 +1,6 @@
 # lock.m4
-# serial 14
+# serial 15
-dnl Copyright (C) 2005-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2005-2026 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.
@@ -12,8 +12,8 @@ AC_DEFUN([gl_LOCK],
 [
  AC_REQUIRE([gl_THREADLIB])
  if test "$gl_threads_api" = posix; then
-    # OSF/1 4.0 and Mac OS X 10.1 lack the pthread_rwlock_t type and the
+    # Mac OS X 10.1 lacks the pthread_rwlock_t type and the pthread_rwlock_*
-    # pthread_rwlock_* functions.
+    # functions.
    has_rwlock=false
    AC_CHECK_TYPE([pthread_rwlock_t],
      [has_rwlock=true
diff --git a/gl/m4/lseek.m4 b/gl/m4/lseek.m4
index ddfadd38..342fc55b 100644
--- a/gl/m4/lseek.m4
+++ b/gl/m4/lseek.m4
@@ -1,6 +1,6 @@
 # lseek.m4
 # serial 15
-dnl Copyright (C) 2007, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007, 2009-2026 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.
diff --git a/gl/m4/lstat.m4 b/gl/m4/lstat.m4
index efae2485..57df6fd9 100644
--- a/gl/m4/lstat.m4
+++ b/gl/m4/lstat.m4
@@ -1,6 +1,6 @@
 # lstat.m4
 # serial 36
-dnl Copyright (C) 1997-2001, 2003-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 1997-2001, 2003-2026 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.
diff --git a/gl/m4/malloc.m4 b/gl/m4/malloc.m4
index 547b4e4d..a95e33db 100644
--- a/gl/m4/malloc.m4
+++ b/gl/m4/malloc.m4
@@ -1,6 +1,6 @@
 # malloc.m4
-# serial 43.1
+# serial 46
-dnl Copyright (C) 2007, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007, 2009-2026 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.
@@ -187,40 +187,42 @@ AC_DEFUN([gl_CHECK_MALLOC_POSIX],
            [gl_cv_func_malloc_posix="guessing yes"],
            [gl_cv_func_malloc_posix="guessing no"])
          ;;
-        irix* | solaris*)
+        solaris*)
-          dnl On IRIX 6.5, the three functions return NULL with errno unset
+          dnl On Solaris 11.3, the three functions might fail with errno set
-          dnl when the argument is larger than PTRDIFF_MAX.
-          dnl On Solaris 11.3, the three functions return NULL with errno set
          dnl to EAGAIN, not ENOMEM, when the argument is larger than
-          dnl PTRDIFF_MAX.
+          dnl PTRDIFF_MAX.  See:
+          dnl https://lists.gnu.org/r/bug-gnulib/2021-05/msg00052.html
          dnl Here is a test program:
 m4_divert_push([KILL])
 #include <errno.h>
+#include <stddef.h>
 #include <stdio.h>
+#include <stdint.h>
 #include <stdlib.h>
-#define ptrdiff_t long
-#ifndef PTRDIFF_MAX
-# define PTRDIFF_MAX ((ptrdiff_t) ((1UL << (8 * sizeof (ptrdiff_t) - 1)) - 1))
-#endif
-int main ()
+#define TEST_CALL(call) \
+  do { \
+    void *p = call; \
+    if (p) \
+      fprintf (stderr, "returned %p (incorrect success)\n", p); \
+    else if (errno == ENOMEM) \
+      perror ("correct failure"); \
+    else \
+      perror ("incorrect failure (wrong errno)"); \
+    free (p); \
+  } while (0)
+int
+main ()
 {
-  void *p;
+  size_t big = PTRDIFF_MAX;
+  TEST_CALL (malloc (big + 1));
-  fprintf (stderr, "PTRDIFF_MAX = %lu\n", (unsigned long) PTRDIFF_MAX);
+  TEST_CALL (calloc (big / 2 + 1, 2));
+  TEST_CALL (realloc (NULL, big + 1));
-  errno = 0;
+  void *small = malloc (1);
-  p = malloc ((unsigned long) PTRDIFF_MAX + 1);
+  TEST_CALL (realloc (small, big + 1));
-  fprintf (stderr, "p=%p errno=%d\n", p, errno);
+  free (small);
-  errno = 0;
-  p = calloc (PTRDIFF_MAX / 2 + 1, 2);
-  fprintf (stderr, "p=%p errno=%d\n", p, errno);
-  errno = 0;
-  p = realloc (NULL, (unsigned long) PTRDIFF_MAX + 1);
-  fprintf (stderr, "p=%p errno=%d\n", p, errno);
  return 0;
 }
 m4_divert_pop([KILL])
diff --git a/gl/m4/malloca.m4 b/gl/m4/malloca.m4
index cabe5fe7..2c0ed8ea 100644
--- a/gl/m4/malloca.m4
+++ b/gl/m4/malloca.m4
@@ -1,6 +1,6 @@
 # malloca.m4
 # serial 3
-dnl Copyright (C) 2003-2004, 2006-2007, 2009-2025 Free Software Foundation,
+dnl Copyright (C) 2003-2004, 2006-2007, 2009-2026 Free Software Foundation,
 dnl Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
diff --git a/gl/m4/math_h.m4 b/gl/m4/math_h.m4
index 8c27503b..4cf59671 100644
--- a/gl/m4/math_h.m4
+++ b/gl/m4/math_h.m4
@@ -1,6 +1,6 @@
 # math_h.m4
-# serial 140.1
+# serial 146
-dnl Copyright (C) 2007-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007-2026 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.
@@ -131,8 +131,11 @@ AC_DEFUN([gl_MATH_H_REQUIRE_DEFAULTS],
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_ILOGBF])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_ILOGBL])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_ISFINITE])
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_ISFINITE_NO_CXX])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_ISINF])
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_ISINF_NO_CXX])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_ISNAN])
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_ISNAN_NO_CXX])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_ISNANF])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_ISNAND])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_ISNANL])
@@ -177,6 +180,7 @@ AC_DEFUN([gl_MATH_H_REQUIRE_DEFAULTS],
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_SETPAYLOADSIGF])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_SETPAYLOADSIGL])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_SIGNBIT])
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_SIGNBIT_NO_CXX])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_SINF])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_SINL])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_SINHF])
@@ -220,14 +224,19 @@ AC_DEFUN([gl_MATH_H_DEFAULTS],
  HAVE_CBRTF=1;                     AC_SUBST([HAVE_CBRTF])
  HAVE_CBRTL=1;                     AC_SUBST([HAVE_CBRTL])
  HAVE_COPYSIGN=1;                  AC_SUBST([HAVE_COPYSIGN])
+  HAVE_COPYSIGNF=1;                 AC_SUBST([HAVE_COPYSIGNF])
  HAVE_COPYSIGNL=1;                 AC_SUBST([HAVE_COPYSIGNL])
  HAVE_COSF=1;                      AC_SUBST([HAVE_COSF])
  HAVE_COSL=1;                      AC_SUBST([HAVE_COSL])
  HAVE_COSHF=1;                     AC_SUBST([HAVE_COSHF])
  HAVE_EXPF=1;                      AC_SUBST([HAVE_EXPF])
  HAVE_EXPL=1;                      AC_SUBST([HAVE_EXPL])
+  HAVE_EXP2=1;                      AC_SUBST([HAVE_EXP2])
+  HAVE_EXP2F=1;                     AC_SUBST([HAVE_EXP2F])
+  HAVE_EXP2L=1;                     AC_SUBST([HAVE_EXP2L])
  HAVE_EXPM1=1;                     AC_SUBST([HAVE_EXPM1])
  HAVE_EXPM1F=1;                    AC_SUBST([HAVE_EXPM1F])
+  HAVE_EXPM1L=1;                    AC_SUBST([HAVE_EXPM1L])
  HAVE_FABSF=1;                     AC_SUBST([HAVE_FABSF])
  HAVE_FABSL=1;                     AC_SUBST([HAVE_FABSL])
  HAVE_FMA=1;                       AC_SUBST([HAVE_FMA])
@@ -255,6 +264,9 @@ AC_DEFUN([gl_MATH_H_DEFAULTS],
  HAVE_LOG1P=1;                     AC_SUBST([HAVE_LOG1P])
  HAVE_LOG1PF=1;                    AC_SUBST([HAVE_LOG1PF])
  HAVE_LOG1PL=1;                    AC_SUBST([HAVE_LOG1PL])
+  HAVE_LOG2=1;                      AC_SUBST([HAVE_LOG2])
+  HAVE_LOG2F=1;                     AC_SUBST([HAVE_LOG2F])
+  HAVE_LOG2L=1;                     AC_SUBST([HAVE_LOG2L])
  HAVE_LOGBF=1;                     AC_SUBST([HAVE_LOGBF])
  HAVE_LOGBL=1;                     AC_SUBST([HAVE_LOGBL])
  HAVE_LOGP1=1;                     AC_SUBST([HAVE_LOGP1])
@@ -265,8 +277,13 @@ AC_DEFUN([gl_MATH_H_DEFAULTS],
  HAVE_POWF=1;                      AC_SUBST([HAVE_POWF])
  HAVE_REMAINDER=1;                 AC_SUBST([HAVE_REMAINDER])
  HAVE_REMAINDERF=1;                AC_SUBST([HAVE_REMAINDERF])
+  HAVE_REMAINDERL=1;                AC_SUBST([HAVE_REMAINDERL])
  HAVE_RINT=1;                      AC_SUBST([HAVE_RINT])
+  HAVE_RINTF=1;                     AC_SUBST([HAVE_RINTF])
  HAVE_RINTL=1;                     AC_SUBST([HAVE_RINTL])
+  HAVE_ROUND=1;                     AC_SUBST([HAVE_ROUND])
+  HAVE_ROUNDF=1;                    AC_SUBST([HAVE_ROUNDF])
+  HAVE_ROUNDL=1;                    AC_SUBST([HAVE_ROUNDL])
  HAVE_SETPAYLOAD=1;                AC_SUBST([HAVE_SETPAYLOAD])
  HAVE_SETPAYLOADF=1;               AC_SUBST([HAVE_SETPAYLOADF])
  HAVE_SETPAYLOADL=1;               AC_SUBST([HAVE_SETPAYLOADL])
@@ -290,33 +307,17 @@ AC_DEFUN([gl_MATH_H_DEFAULTS],
  HAVE_DECL_ACOSL=1;                AC_SUBST([HAVE_DECL_ACOSL])
  HAVE_DECL_ASINL=1;                AC_SUBST([HAVE_DECL_ASINL])
  HAVE_DECL_ATANL=1;                AC_SUBST([HAVE_DECL_ATANL])
-  HAVE_DECL_CBRTF=1;                AC_SUBST([HAVE_DECL_CBRTF])
-  HAVE_DECL_CBRTL=1;                AC_SUBST([HAVE_DECL_CBRTL])
  HAVE_DECL_CEILF=1;                AC_SUBST([HAVE_DECL_CEILF])
  HAVE_DECL_CEILL=1;                AC_SUBST([HAVE_DECL_CEILL])
-  HAVE_DECL_COPYSIGNF=1;            AC_SUBST([HAVE_DECL_COPYSIGNF])
  HAVE_DECL_COSL=1;                 AC_SUBST([HAVE_DECL_COSL])
  HAVE_DECL_EXPL=1;                 AC_SUBST([HAVE_DECL_EXPL])
-  HAVE_DECL_EXP2=1;                 AC_SUBST([HAVE_DECL_EXP2])
-  HAVE_DECL_EXP2F=1;                AC_SUBST([HAVE_DECL_EXP2F])
-  HAVE_DECL_EXP2L=1;                AC_SUBST([HAVE_DECL_EXP2L])
-  HAVE_DECL_EXPM1L=1;               AC_SUBST([HAVE_DECL_EXPM1L])
  HAVE_DECL_FLOORF=1;               AC_SUBST([HAVE_DECL_FLOORF])
  HAVE_DECL_FLOORL=1;               AC_SUBST([HAVE_DECL_FLOORL])
  HAVE_DECL_FREXPL=1;               AC_SUBST([HAVE_DECL_FREXPL])
  HAVE_DECL_LDEXPL=1;               AC_SUBST([HAVE_DECL_LDEXPL])
  HAVE_DECL_LOGL=1;                 AC_SUBST([HAVE_DECL_LOGL])
  HAVE_DECL_LOG10L=1;               AC_SUBST([HAVE_DECL_LOG10L])
-  HAVE_DECL_LOG2=1;                 AC_SUBST([HAVE_DECL_LOG2])
-  HAVE_DECL_LOG2F=1;                AC_SUBST([HAVE_DECL_LOG2F])
-  HAVE_DECL_LOG2L=1;                AC_SUBST([HAVE_DECL_LOG2L])
  HAVE_DECL_LOGB=1;                 AC_SUBST([HAVE_DECL_LOGB])
-  HAVE_DECL_REMAINDER=1;            AC_SUBST([HAVE_DECL_REMAINDER])
-  HAVE_DECL_REMAINDERL=1;           AC_SUBST([HAVE_DECL_REMAINDERL])
-  HAVE_DECL_RINTF=1;                AC_SUBST([HAVE_DECL_RINTF])
-  HAVE_DECL_ROUND=1;                AC_SUBST([HAVE_DECL_ROUND])
-  HAVE_DECL_ROUNDF=1;               AC_SUBST([HAVE_DECL_ROUNDF])
-  HAVE_DECL_ROUNDL=1;               AC_SUBST([HAVE_DECL_ROUNDL])
  HAVE_DECL_SINL=1;                 AC_SUBST([HAVE_DECL_SINL])
  HAVE_DECL_SQRTL=1;                AC_SUBST([HAVE_DECL_SQRTL])
  HAVE_DECL_TANL=1;                 AC_SUBST([HAVE_DECL_TANL])
diff --git a/gl/m4/mbchar.m4 b/gl/m4/mbchar.m4
index b76f1d7b..4251a84c 100644
--- a/gl/m4/mbchar.m4
+++ b/gl/m4/mbchar.m4
@@ -1,6 +1,6 @@
 # mbchar.m4
 # serial 9
-dnl Copyright (C) 2005-2007, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2005-2007, 2009-2026 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.
diff --git a/gl/m4/mbiter.m4 b/gl/m4/mbiter.m4
index b51242e6..927876bc 100644
--- a/gl/m4/mbiter.m4
+++ b/gl/m4/mbiter.m4
@@ -1,6 +1,6 @@
 # mbiter.m4
 # serial 7
-dnl Copyright (C) 2005, 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2005, 2008-2026 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.
diff --git a/gl/m4/mbrtoc32.m4 b/gl/m4/mbrtoc32.m4
index 1991529c..d1690fb4 100644
--- a/gl/m4/mbrtoc32.m4
+++ b/gl/m4/mbrtoc32.m4
@@ -1,6 +1,6 @@
 # mbrtoc32.m4
 # serial 21
-dnl Copyright (C) 2014-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2014-2026 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.
diff --git a/gl/m4/mbrtowc.m4 b/gl/m4/mbrtowc.m4
index cc09a5fb..a49872fa 100644
--- a/gl/m4/mbrtowc.m4
+++ b/gl/m4/mbrtowc.m4
@@ -1,6 +1,6 @@
 # mbrtowc.m4
-# serial 46
+# serial 47
-dnl Copyright (C) 2001-2002, 2004-2005, 2008-2025 Free Software Foundation,
+dnl Copyright (C) 2001-2002, 2004-2005, 2008-2026 Free Software Foundation,
 dnl Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -33,7 +33,6 @@ AC_DEFUN([gl_FUNC_MBRTOWC],
      REPLACE_MBRTOWC=1
    else
      gl_MBRTOWC_NULL_ARG1
-      gl_MBRTOWC_NULL_ARG2
      gl_MBRTOWC_RETVAL
      gl_MBRTOWC_NUL_RETVAL
      gl_MBRTOWC_STORES_INCOMPLETE
@@ -46,13 +45,6 @@ AC_DEFUN([gl_FUNC_MBRTOWC],
           REPLACE_MBRTOWC=1
           ;;
      esac
-      case "$gl_cv_func_mbrtowc_null_arg2" in
-        *yes) ;;
-        *) AC_DEFINE([MBRTOWC_NULL_ARG2_BUG], [1],
-             [Define if the mbrtowc function has the NULL string argument bug.])
-           REPLACE_MBRTOWC=1
-           ;;
-      esac
      case "$gl_cv_func_mbrtowc_retval" in
        *yes) ;;
        *) AC_DEFINE([MBRTOWC_RETVAL_BUG], [1],
@@ -170,10 +162,10 @@ AC_DEFUN([gl_MBRTOWC_INCOMPLETE_STATE],
      dnl is present.
 changequote(,)dnl
      case "$host_os" in
-                     # Guess no on AIX and OSF/1.
+              # Guess no on AIX.
-        aix* | osf*) gl_cv_func_mbrtowc_incomplete_state="guessing no" ;;
+        aix*) gl_cv_func_mbrtowc_incomplete_state="guessing no" ;;
-                     # Guess yes otherwise.
+              # Guess yes otherwise.
-        *)           gl_cv_func_mbrtowc_incomplete_state="guessing yes" ;;
+        *)    gl_cv_func_mbrtowc_incomplete_state="guessing yes" ;;
      esac
 changequote([,])dnl
      if test $LOCALE_JA != none; then
@@ -346,57 +338,6 @@ int main ()
    ])
 ])
-dnl Test whether mbrtowc supports a NULL string argument correctly.
-dnl Result is gl_cv_func_mbrtowc_null_arg2.
-AC_DEFUN([gl_MBRTOWC_NULL_ARG2],
-[
-  AC_REQUIRE([AC_PROG_CC])
-  AC_REQUIRE([gt_LOCALE_EN_UTF8])
-  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
-  AC_CACHE_CHECK([whether mbrtowc handles a NULL string argument],
-    [gl_cv_func_mbrtowc_null_arg2],
-    [
-      dnl Initial guess, used when cross-compiling or when no suitable locale
-      dnl is present.
-changequote(,)dnl
-      case "$host_os" in
-              # Guess no on OSF/1.
-        osf*) gl_cv_func_mbrtowc_null_arg2="guessing no" ;;
-              # Guess yes otherwise.
-        *)    gl_cv_func_mbrtowc_null_arg2="guessing yes" ;;
-      esac
-changequote([,])dnl
-      if test "$LOCALE_EN_UTF8" != none; then
-        AC_RUN_IFELSE(
-          [AC_LANG_SOURCE([[
-#include <locale.h>
-#include <string.h>
-#include <wchar.h>
-int main ()
-{
-  if (setlocale (LC_ALL, "$LOCALE_EN_UTF8") != NULL)
-    {
-      mbstate_t state;
-      wchar_t wc;
-      int ret;
-      memset (&state, '\0', sizeof (mbstate_t));
-      wc = (wchar_t) 0xBADFACE;
-      mbrtowc (&wc, NULL, 5, &state);
-      /* Check that wc was not modified.  */
-      if (wc != (wchar_t) 0xBADFACE)
-        return 2;
-    }
-  return 0;
-}]])],
-          [gl_cv_func_mbrtowc_null_arg2=yes],
-          [gl_cv_func_mbrtowc_null_arg2=no],
-          [:])
-      fi
-    ])
-])
 dnl Test whether mbrtowc, when parsing the end of a multibyte character,
 dnl correctly returns the number of bytes that were needed to complete the
 dnl character (not the total number of bytes of the multibyte character).
@@ -716,7 +657,7 @@ AC_DEFUN([gl_MBRTOWC_EMPTY_INPUT],
 dnl Test whether mbrtowc reports encoding errors in the C locale.
 dnl Although POSIX was never intended to allow this, the GNU C Library
 dnl and other implementations do it.  See:
-dnl https://sourceware.org/bugzilla/show_bug.cgi?id=19932
+dnl https://sourceware.org/PR19932
 dnl POSIX has now clarified it:
 dnl <https://pubs.opengroup.org/onlinepubs/9699919799/functions/mbrtowc.html>
 dnl says: "In the POSIX locale an [EILSEQ] error cannot occur since all byte
diff --git a/gl/m4/mbsinit.m4 b/gl/m4/mbsinit.m4
index 69cfa574..757f2360 100644
--- a/gl/m4/mbsinit.m4
+++ b/gl/m4/mbsinit.m4
@@ -1,6 +1,6 @@
 # mbsinit.m4
 # serial 10
-dnl Copyright (C) 2008, 2010-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2008, 2010-2026 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.
diff --git a/gl/m4/mbstate_t.m4 b/gl/m4/mbstate_t.m4
index 59df1e2e..88307d7a 100644
--- a/gl/m4/mbstate_t.m4
+++ b/gl/m4/mbstate_t.m4
@@ -1,6 +1,6 @@
 # mbstate_t.m4
 # serial 14
-dnl Copyright (C) 2000-2002, 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2000-2002, 2008-2026 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.
diff --git a/gl/m4/mbtowc.m4 b/gl/m4/mbtowc.m4
index 3e3f6ce0..9c5887d3 100644
--- a/gl/m4/mbtowc.m4
+++ b/gl/m4/mbtowc.m4
@@ -1,6 +1,6 @@
 # mbtowc.m4
 # serial 5
-dnl Copyright (C) 2011-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2011-2026 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.
diff --git a/gl/m4/memchr.m4 b/gl/m4/memchr.m4
index 1c2ecf1d..c5c74682 100644
--- a/gl/m4/memchr.m4
+++ b/gl/m4/memchr.m4
@@ -1,6 +1,6 @@
 # memchr.m4
-# serial 20
+# serial 21
-dnl Copyright (C) 2002-2004, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2002-2004, 2009-2026 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.
@@ -21,7 +21,7 @@ AC_DEFUN_ONCE([gl_FUNC_MEMCHR],
  #   https://bugzilla.redhat.com/show_bug.cgi?id=499689
  # memchr should not dereference overestimated length after a match
  #   https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=521737
-  #   https://sourceware.org/bugzilla/show_bug.cgi?id=10162
+  #   https://sourceware.org/PR10162
  # memchr should cast the second argument to 'unsigned char'.
  #   This bug exists in Android 4.3.
  # Assume that memchr works on platforms that lack mprotect.
@@ -33,31 +33,20 @@ AC_DEFUN_ONCE([gl_FUNC_MEMCHR],
 # include <unistd.h>
 # include <sys/types.h>
 # include <sys/mman.h>
-# ifndef MAP_FILE
-#  define MAP_FILE 0
-# endif
 #endif
 ]], [[
  int result = 0;
  char *fence = NULL;
 #if HAVE_SYS_MMAN_H && HAVE_MPROTECT
-# if HAVE_MAP_ANONYMOUS
+  {
-  const int flags = MAP_ANONYMOUS | MAP_PRIVATE;
+    long int pagesize = sysconf (_SC_PAGESIZE);
-  const int fd = -1;
+    char *two_pages =
-# else /* !HAVE_MAP_ANONYMOUS */
+      (char *) mmap (NULL, 2 * pagesize, PROT_READ | PROT_WRITE,
-  const int flags = MAP_FILE | MAP_PRIVATE;
+                     MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
-  int fd = open ("/dev/zero", O_RDONLY, 0666);
+    if (two_pages != (char *)(-1)
-  if (fd >= 0)
+        && mprotect (two_pages + pagesize, pagesize, PROT_NONE) == 0)
-# endif
+      fence = two_pages + pagesize;
-    {
+  }
-      long int pagesize = sysconf (_SC_PAGESIZE);
-      char *two_pages =
-        (char *) mmap (NULL, 2 * pagesize, PROT_READ | PROT_WRITE,
-                       flags, fd, 0);
-      if (two_pages != (char *)(-1)
-          && mprotect (two_pages + pagesize, pagesize, PROT_NONE) == 0)
-        fence = two_pages + pagesize;
-    }
 #endif
  if (fence)
    {
diff --git a/gl/m4/minmax.m4 b/gl/m4/minmax.m4
index 69c8a89f..3344e3f7 100644
--- a/gl/m4/minmax.m4
+++ b/gl/m4/minmax.m4
@@ -1,6 +1,6 @@
 # minmax.m4
 # serial 4
-dnl Copyright (C) 2005, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2005, 2009-2026 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.
diff --git a/gl/m4/mktime.m4 b/gl/m4/mktime.m4
index eca6c4d8..fa32d138 100644
--- a/gl/m4/mktime.m4
+++ b/gl/m4/mktime.m4
@@ -1,6 +1,6 @@
 # mktime.m4
-# serial 42
+# serial 43
-dnl Copyright (C) 2002-2003, 2005-2007, 2009-2025 Free Software Foundation,
+dnl Copyright (C) 2002-2003, 2005-2007, 2009-2026 Free Software Foundation,
 dnl Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -113,22 +113,6 @@ mktime_test (time_t now)
 }
 static int
-irix_6_4_bug ()
-{
-  /* Based on code from Ariel Faigon.  */
-  struct tm tm;
-  tm.tm_year = 96;
-  tm.tm_mon = 3;
-  tm.tm_mday = 0;
-  tm.tm_hour = 0;
-  tm.tm_min = 0;
-  tm.tm_sec = 0;
-  tm.tm_isdst = -1;
-  mktime (&tm);
-  return tm.tm_mon == 2 && tm.tm_mday == 31;
-}
-static int
 bigtime_test (int j)
 {
  struct tm tm;
@@ -255,12 +239,10 @@ main ()
      if ((result & 8) == 0 && ! bigtime_test (INT_MAX))
        result |= 8;
    }
-  if (! irix_6_4_bug ())
-    result |= 16;
  if (! spring_forward_gap ())
-    result |= 32;
+    result |= 16;
  if (! year_2050_test () || ! indiana_test ())
-    result |= 64;
+    result |= 32;
  return result;
 }]])],
         [gl_cv_func_working_mktime=yes],
diff --git a/gl/m4/mmap-anon.m4 b/gl/m4/mmap-anon.m4
index 3f7a6656..b5e323d4 100644
--- a/gl/m4/mmap-anon.m4
+++ b/gl/m4/mmap-anon.m4
@@ -1,6 +1,6 @@
 # mmap-anon.m4
-# serial 12
+# serial 15
-dnl Copyright (C) 2005, 2007, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2005, 2007, 2009-2026 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.
@@ -8,12 +8,10 @@ dnl This file is offered as-is, without any warranty.
 # Detect how mmap can be used to create anonymous (not file-backed) memory
 # mappings.
-# - On Linux, AIX, OSF/1, Solaris, Cygwin, Interix, Haiku, both MAP_ANONYMOUS
+# - On Linux, AIX, Solaris, Cygwin, Interix, Haiku, both MAP_ANONYMOUS and
-#   and MAP_ANON exist and have the same value.
+#   MAP_ANON exist and have the same value.
 # - On HP-UX, only MAP_ANONYMOUS exists.
 # - On Mac OS X, FreeBSD, NetBSD, OpenBSD, Minix, only MAP_ANON exists.
-# - On IRIX, neither exists, and a file descriptor opened to /dev/zero must be
-#   used.
 AC_DEFUN_ONCE([gl_FUNC_MMAP_ANON],
 [
@@ -23,11 +21,13 @@ AC_DEFUN_ONCE([gl_FUNC_MMAP_ANON],
  # Check for mmap(). Don't use AC_FUNC_MMAP, because it checks too much: it
  # fails on HP-UX 11, because MAP_FIXED mappings do not work. But this is
  # irrelevant for anonymous mappings.
-  AC_CHECK_FUNC([mmap], [gl_have_mmap=yes], [gl_have_mmap=no])
+  # Instead, assume that mmap() exists if and only if <sys/mman.h> exists.
+  # Code needs to tests HAVE_SYS_MMAN_H, not HAVE_MMAP.
+  AC_CHECK_HEADERS_ONCE([sys/mman.h])
  # Try to allow MAP_ANONYMOUS.
  gl_have_mmap_anonymous=no
-  if test $gl_have_mmap = yes; then
+  if test $ac_cv_header_sys_mman_h = yes; then
    AC_MSG_CHECKING([for MAP_ANONYMOUS])
    AC_EGREP_CPP([I cannot identify this map], [
 #include <sys/mman.h>
@@ -48,10 +48,5 @@ AC_DEFUN_ONCE([gl_FUNC_MMAP_ANON],
         gl_have_mmap_anonymous=yes])
    fi
    AC_MSG_RESULT([$gl_have_mmap_anonymous])
-    if test $gl_have_mmap_anonymous = yes; then
-      AC_DEFINE([HAVE_MAP_ANONYMOUS], [1],
-        [Define to 1 if mmap()'s MAP_ANONYMOUS flag is available after including
-         config.h and <sys/mman.h>.])
-    fi
  fi
 ])
diff --git a/gl/m4/mode_t.m4 b/gl/m4/mode_t.m4
index 7dae201b..4621813d 100644
--- a/gl/m4/mode_t.m4
+++ b/gl/m4/mode_t.m4
@@ -1,6 +1,6 @@
 # mode_t.m4
 # serial 2
-dnl Copyright (C) 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2009-2026 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.
diff --git a/gl/m4/mountlist.m4 b/gl/m4/mountlist.m4
index e7eac2e9..311e00b2 100644
--- a/gl/m4/mountlist.m4
+++ b/gl/m4/mountlist.m4
@@ -1,6 +1,6 @@
 # mountlist.m4
-# serial 18
+# serial 20
-dnl Copyright (C) 2002-2006, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2002-2006, 2009-2026 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.
@@ -75,7 +75,7 @@ $ac_includes_default
    # Determine whether it's the one-argument variant or the two-argument one.
    if test -z "$ac_list_mounted_fs"; then
-      # glibc, HP-UX, IRIX, Cygwin, Android, also (obsolete) 4.3BSD, SunOS.
+      # glibc, HP-UX, Cygwin, Android, also (obsolete) 4.3BSD, SunOS.
      AC_CACHE_CHECK([for one-argument getmntent function],
        [fu_cv_sys_mounted_getmntent1],
        [AC_COMPILE_IFELSE(
@@ -107,7 +107,7 @@ $ac_includes_default
        AC_DEFINE([MOUNTED_GETMNTENT1], [1],
          [Define if there is a function named getmntent for reading the list
           of mounted file systems, and that function takes a single argument.
-           (4.3BSD, SunOS, HP-UX, Irix)])
+           (4.3BSD, SunOS, HP-UX)])
        gl_CHECK_FUNCS_ANDROID([setmntent],
          [[#include <stdio.h>
            #include <mntent.h>
@@ -159,7 +159,7 @@ $ac_includes_default
  fi
  if test -z "$ac_list_mounted_fs"; then
-    # OSF/1, also (obsolete) Apple Darwin 1.3.
+    # (obsolete) Apple Darwin 1.3.
    # powerpc-apple-darwin1.3.7 needs sys/param.h sys/ucred.h sys/fs_types.h
    AC_CACHE_CHECK([for getfsstat function],
@@ -185,7 +185,7 @@ $getfsstat_includes
      ac_list_mounted_fs=found
      AC_DEFINE([MOUNTED_GETFSSTAT], [1],
        [Define if there is a function named getfsstat for reading the
-         list of mounted file systems.  (DEC Alpha running OSF/1)])
+         list of mounted file systems.  (obsolete Darwin)])
    fi
  fi
@@ -212,10 +212,9 @@ $getfsstat_includes
  if test -z "$ac_list_mounted_fs"; then
    # Mac OS X, FreeBSD, NetBSD, OpenBSD, Minix, also (obsolete) 4.4BSD.
-    # OSF/1 also has getmntinfo but is already handled above.
    # We cannot use AC_CHECK_FUNCS([getmntinfo]) here, because at the linker
    # level the function is sometimes called getmntinfo64 or getmntinfo$INODE64
-    # on Mac OS X, __getmntinfo13 on NetBSD and Minix, _F64_getmntinfo on OSF/1.
+    # on Mac OS X, __getmntinfo13 on NetBSD and Minix.
    AC_CACHE_CHECK([for getmntinfo function],
      [fu_cv_sys_mounted_getmntinfo],
      [AC_LINK_IFELSE(
diff --git a/gl/m4/msvc-inval.m4 b/gl/m4/msvc-inval.m4
index bfbb983b..565c0d3a 100644
--- a/gl/m4/msvc-inval.m4
+++ b/gl/m4/msvc-inval.m4
@@ -1,6 +1,6 @@
 # msvc-inval.m4
 # serial 1
-dnl Copyright (C) 2011-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2011-2026 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.
diff --git a/gl/m4/msvc-nothrow.m4 b/gl/m4/msvc-nothrow.m4
index 6a470971..1c2b491e 100644
--- a/gl/m4/msvc-nothrow.m4
+++ b/gl/m4/msvc-nothrow.m4
@@ -1,6 +1,6 @@
 # msvc-nothrow.m4
 # serial 1
-dnl Copyright (C) 2011-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2011-2026 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.
diff --git a/gl/m4/multiarch.m4 b/gl/m4/multiarch.m4
index 817f01f1..4fb642b7 100644
--- a/gl/m4/multiarch.m4
+++ b/gl/m4/multiarch.m4
@@ -1,6 +1,6 @@
 # multiarch.m4
 # serial 9
-dnl Copyright (C) 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2008-2026 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.
diff --git a/gl/m4/musl.m4 b/gl/m4/musl.m4
index 6ff778cb..15b34466 100644
--- a/gl/m4/musl.m4
+++ b/gl/m4/musl.m4
@@ -1,6 +1,6 @@
 # musl.m4
 # serial 4
-dnl Copyright (C) 2019-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2019-2026 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.
diff --git a/gl/m4/netdb_h.m4 b/gl/m4/netdb_h.m4
index 88512546..bcf19b01 100644
--- a/gl/m4/netdb_h.m4
+++ b/gl/m4/netdb_h.m4
@@ -1,6 +1,6 @@
 # netdb_h.m4
 # serial 15
-dnl Copyright (C) 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2008-2026 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.
diff --git a/gl/m4/netinet_in_h.m4 b/gl/m4/netinet_in_h.m4
index b56e354c..6d9eaf97 100644
--- a/gl/m4/netinet_in_h.m4
+++ b/gl/m4/netinet_in_h.m4
@@ -1,6 +1,6 @@
 # netinet_in_h.m4
 # serial 6
-dnl Copyright (C) 2006-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2006-2026 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.
diff --git a/gl/m4/nl_langinfo.m4 b/gl/m4/nl_langinfo.m4
index 9b1e0f32..a3ec57f7 100644
--- a/gl/m4/nl_langinfo.m4
+++ b/gl/m4/nl_langinfo.m4
@@ -1,6 +1,6 @@
 # nl_langinfo.m4
-# serial 12.1
+# serial 14
-dnl Copyright (C) 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2009-2026 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.
@@ -16,31 +16,6 @@ AC_DEFUN([gl_FUNC_NL_LANGINFO],
  AC_REQUIRE([gl_PTHREADLIB])
  AC_CHECK_HEADERS_ONCE([threads.h])
  if test $ac_cv_func_nl_langinfo = yes; then
-    # On Irix 6.5, YESEXPR is defined, but nl_langinfo(YESEXPR) is broken.
-    AC_CACHE_CHECK([whether YESEXPR works],
-      [gl_cv_func_nl_langinfo_yesexpr_works],
-      [AC_RUN_IFELSE(
-         [AC_LANG_PROGRAM([[#include <langinfo.h>
-]], [[return !*nl_langinfo(YESEXPR);
-]])],
-         [gl_cv_func_nl_langinfo_yesexpr_works=yes],
-         [gl_cv_func_nl_langinfo_yesexpr_works=no],
-         [
-         case "$host_os" in
-                   # Guess no on irix systems.
-           irix*)  gl_cv_func_nl_langinfo_yesexpr_works="guessing no";;
-                   # Guess yes elsewhere.
-           *)      gl_cv_func_nl_langinfo_yesexpr_works="guessing yes";;
-         esac
-         ])
-      ])
-    case $gl_cv_func_nl_langinfo_yesexpr_works in
-      *yes) FUNC_NL_LANGINFO_YESEXPR_WORKS=1 ;;
-      *)    FUNC_NL_LANGINFO_YESEXPR_WORKS=0 ;;
-    esac
-    AC_DEFINE_UNQUOTED([FUNC_NL_LANGINFO_YESEXPR_WORKS],
-      [$FUNC_NL_LANGINFO_YESEXPR_WORKS],
-      [Define to 1 if nl_langinfo (YESEXPR) returns a non-empty string.])
    # On macOS 26, Solaris 10, and Solaris 11.3, nl_langinfo is not
    # multithread-safe.
    case "$host_os" in
@@ -50,11 +25,9 @@ AC_DEFUN([gl_FUNC_NL_LANGINFO],
    AC_DEFINE_UNQUOTED([NL_LANGINFO_MTSAFE], [$NL_LANGINFO_MTSAFE],
      [Define to 1 if nl_langinfo is multithread-safe.])
    if test $HAVE_LANGINFO_CODESET = 1 \
-       && test $HAVE_LANGINFO_T_FMT_AMPM = 1 \
       && test $HAVE_LANGINFO_ALTMON = 1 \
       && test $HAVE_LANGINFO_ABALTMON = 1 \
       && test $HAVE_LANGINFO_ERA = 1 \
-       && test $FUNC_NL_LANGINFO_YESEXPR_WORKS = 1 \
       && test $NL_LANGINFO_MTSAFE = 1; then
      :
    else
diff --git a/gl/m4/nocrash.m4 b/gl/m4/nocrash.m4
index 662fb049..5c1af8c7 100644
--- a/gl/m4/nocrash.m4
+++ b/gl/m4/nocrash.m4
@@ -1,6 +1,6 @@
 # nocrash.m4
 # serial 5
-dnl Copyright (C) 2005, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2005, 2009-2026 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.
diff --git a/gl/m4/off64_t.m4 b/gl/m4/off64_t.m4
index 963d53e9..93d9e37b 100644
--- a/gl/m4/off64_t.m4
+++ b/gl/m4/off64_t.m4
@@ -1,6 +1,6 @@
 # off64_t.m4
 # serial 1
-dnl Copyright (C) 2024-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2024-2026 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.
diff --git a/gl/m4/off_t.m4 b/gl/m4/off_t.m4
index f4f4bbf6..d7d6aa0c 100644
--- a/gl/m4/off_t.m4
+++ b/gl/m4/off_t.m4
@@ -1,6 +1,6 @@
 # off_t.m4
 # serial 1
-dnl Copyright (C) 2012-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2012-2026 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.
diff --git a/gl/m4/once.m4 b/gl/m4/once.m4
index 7876a8fe..a478d81a 100644
--- a/gl/m4/once.m4
+++ b/gl/m4/once.m4
@@ -1,6 +1,6 @@
 # once.m4
 # serial 1
-dnl Copyright (C) 2024-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2024-2026 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.
diff --git a/gl/m4/open-cloexec.m4 b/gl/m4/open-cloexec.m4
index 860541b0..9c9aef23 100644
--- a/gl/m4/open-cloexec.m4
+++ b/gl/m4/open-cloexec.m4
@@ -1,6 +1,6 @@
 # open-cloexec.m4
 # serial 1
-dnl Copyright 2017-2025 Free Software Foundation, Inc.
+dnl Copyright 2017-2026 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.
diff --git a/gl/m4/open-slash.m4 b/gl/m4/open-slash.m4
index 2cba48fe..c36bdced 100644
--- a/gl/m4/open-slash.m4
+++ b/gl/m4/open-slash.m4
@@ -1,6 +1,6 @@
 # open-slash.m4
 # serial 2
-dnl Copyright (C) 2007-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007-2026 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.
diff --git a/gl/m4/open.m4 b/gl/m4/open.m4
index dd3a805f..f5b2a91c 100644
--- a/gl/m4/open.m4
+++ b/gl/m4/open.m4
@@ -1,6 +1,6 @@
 # open.m4
 # serial 17
-dnl Copyright (C) 2007-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007-2026 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.
diff --git a/gl/m4/pathmax.m4 b/gl/m4/pathmax.m4
index 0c3925df..d6bdf43e 100644
--- a/gl/m4/pathmax.m4
+++ b/gl/m4/pathmax.m4
@@ -1,6 +1,6 @@
 # pathmax.m4
 # serial 11
-dnl Copyright (C) 2002-2003, 2005-2006, 2009-2025 Free Software Foundation,
+dnl Copyright (C) 2002-2003, 2005-2006, 2009-2026 Free Software Foundation,
 dnl Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
diff --git a/gl/m4/pid_t.m4 b/gl/m4/pid_t.m4
index a8bdabc2..314792ed 100644
--- a/gl/m4/pid_t.m4
+++ b/gl/m4/pid_t.m4
@@ -1,6 +1,6 @@
 # pid_t.m4
 # serial 4
-dnl Copyright (C) 2020-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2020-2026 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.
diff --git a/gl/m4/printf.m4 b/gl/m4/printf.m4
index 4619a402..0de493b6 100644
--- a/gl/m4/printf.m4
+++ b/gl/m4/printf.m4
@@ -1,6 +1,6 @@
 # printf.m4
-# serial 96
+# serial 98
-dnl Copyright (C) 2003, 2007-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2003, 2007-2026 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.
@@ -659,7 +659,7 @@ int main ()
          && strcmp (buf, "0x8.0p-2") != 0))
    result |= 16;
  /* This catches the same Mac OS X 10.3.9 (Darwin 7.9) bug and also a
-     glibc 2.4 bug <https://sourceware.org/bugzilla/show_bug.cgi?id=2908>
+     glibc 2.4 bug <https://sourceware.org/PR2908>
     and a FreeBSD 6.4, NetBSD 10.0 bug.  */
  if (sprintf (buf, "%.1La", 1.999L) < 0
      || (strcmp (buf, "0x1.0p+1") != 0
@@ -937,7 +937,7 @@ int main ()
  _CrtSetReportMode (_CRT_ASSERT, 0);
 #endif
  signal (SIGABRT, abort_handler);
-  /* Copy the format string.  Some systems (glibc with _FORTIFY_SOURCE=2)
+  /* Copy the format string.  Some systems (glibc with _FORTIFY_SOURCE >= 2)
     support %n in format strings in read-only memory but not in writable
     memory.  */
  strcpy (fmtstring, "%d %n");
@@ -994,7 +994,7 @@ int main ()
  int result = 0;
  char buf[100];
  /* Test whether %ls works at all.
-     This test fails on OpenBSD 4.0, IRIX 6.5, Solaris 2.6, Haiku, but not on
+     This test fails on OpenBSD 4.0, Solaris 2.6, Haiku, but not on
     Cygwin 1.5.  */
  {
    static const wchar_t wstring[] = { 'a', 'b', 'c', 0 };
@@ -1003,8 +1003,8 @@ int main ()
        || strcmp (buf, "abc") != 0)
      result |= 1;
  }
-  /* This test fails on IRIX 6.5, Solaris 2.6, Cygwin 1.5, Haiku (with an
+  /* This test fails on Solaris 2.6, Cygwin 1.5, Haiku (with an assertion
-     assertion failure inside libc), but not on OpenBSD 4.0.  */
+     failure inside libc), but not on OpenBSD 4.0.  */
  {
    static const wchar_t wstring[] = { 'a', 0 };
    buf[0] = '\0';
@@ -1037,7 +1037,6 @@ changequote(,)dnl
                              # Guess yes on OpenBSD >= 6.0.
           openbsd[1-5].*)    gl_cv_func_printf_directive_ls="guessing no";;
           openbsd*)          gl_cv_func_printf_directive_ls="guessing yes";;
-           irix*)             gl_cv_func_printf_directive_ls="guessing no";;
           solaris*)          gl_cv_func_printf_directive_ls="guessing no";;
           cygwin*)           gl_cv_func_printf_directive_ls="guessing no";;
           beos* | haiku*)    gl_cv_func_printf_directive_ls="guessing no";;
@@ -1589,10 +1588,6 @@ changequote(,)dnl
                             *)     gl_cv_func_printf_enomem="guessing no";;
                           esac
                           ;;
-                           # Guess yes on IRIX.
-          irix*)           gl_cv_func_printf_enomem="guessing yes";;
-                           # Guess yes on OSF/1.
-          osf*)            gl_cv_func_printf_enomem="guessing yes";;
                           # Guess yes on BeOS.
          beos*)           gl_cv_func_printf_enomem="guessing yes";;
                           # Guess yes on Haiku.
@@ -1684,11 +1679,6 @@ changequote(,)dnl
                                 # Guess yes on HP-UX >= 11.
           hpux[7-9]* | hpux10*) gl_cv_func_snprintf_truncation_c99="guessing no";;
           hpux*)                gl_cv_func_snprintf_truncation_c99="guessing yes";;
-                                 # Guess yes on IRIX >= 6.5.
-           irix6.5)              gl_cv_func_snprintf_truncation_c99="guessing yes";;
-                                 # Guess yes on OSF/1 >= 5.
-           osf[3-4]*)            gl_cv_func_snprintf_truncation_c99="guessing no";;
-           osf*)                 gl_cv_func_snprintf_truncation_c99="guessing yes";;
                                 # Guess yes on NetBSD >= 3.
           netbsd[1-2]* | netbsdelf[1-2]* | netbsdaout[1-2]* | netbsdcoff[1-2]*)
                                 gl_cv_func_snprintf_truncation_c99="guessing no";;
@@ -1710,7 +1700,7 @@ changequote([,])dnl
 dnl Test whether the return value of the snprintf function is the number
 dnl of bytes (excluding the terminating NUL) that would have been produced
 dnl if the buffer had been large enough. (ISO C99, POSIX:2001)
-dnl For example, this test program fails on IRIX 6.5:
+dnl For example, this test program fails on HP-UX 11.31 and Solaris 9:
 dnl     ---------------------------------------------------------------------
 dnl     #include <stdio.h>
 dnl     int main()
@@ -1859,7 +1849,7 @@ int main ()
 {
  int count = -1;
  signal (SIGABRT, abort_handler);
-  /* Copy the format string.  Some systems (glibc with _FORTIFY_SOURCE=2)
+  /* Copy the format string.  Some systems (glibc with _FORTIFY_SOURCE >= 2)
     support %n in format strings in read-only memory but not in writable
     memory.  */
  strcpy (fmtstring, "%d %n");
@@ -1899,11 +1889,6 @@ changequote(,)dnl
                                 # Guess yes on AIX >= 4.
           aix[1-3]*)            gl_cv_func_snprintf_directive_n="guessing no";;
           aix*)                 gl_cv_func_snprintf_directive_n="guessing yes";;
-                                 # Guess yes on IRIX >= 6.5.
-           irix6.5)              gl_cv_func_snprintf_directive_n="guessing yes";;
-                                 # Guess yes on OSF/1 >= 5.
-           osf[3-4]*)            gl_cv_func_snprintf_directive_n="guessing no";;
-           osf*)                 gl_cv_func_snprintf_directive_n="guessing yes";;
                                 # Guess yes on NetBSD >= 3.
           netbsd[1-2]* | netbsdelf[1-2]* | netbsdaout[1-2]* | netbsdcoff[1-2]*)
                                 gl_cv_func_snprintf_directive_n="guessing no";;
@@ -2058,8 +2043,6 @@ changequote(,)dnl
                                    # Guess yes on AIX >= 4.
           aix[1-3]*)               gl_cv_func_vsnprintf_zerosize_c99="guessing no";;
           aix*)                    gl_cv_func_vsnprintf_zerosize_c99="guessing yes";;
-                                    # Guess yes on IRIX >= 6.5.
-           irix6.5)                 gl_cv_func_vsnprintf_zerosize_c99="guessing yes";;
                                    # Guess yes on NetBSD >= 3.
           netbsd[1-2]* | netbsdelf[1-2]* | netbsdaout[1-2]* | netbsdcoff[1-2]*)
                                    gl_cv_func_vsnprintf_zerosize_c99="guessing no";;
diff --git a/gl/m4/pthread-once.m4 b/gl/m4/pthread-once.m4
index 85549254..9080363d 100644
--- a/gl/m4/pthread-once.m4
+++ b/gl/m4/pthread-once.m4
@@ -1,6 +1,6 @@
 # pthread-once.m4
 # serial 6
-dnl Copyright (C) 2019-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2019-2026 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.
diff --git a/gl/m4/pthread-spin.m4 b/gl/m4/pthread-spin.m4
index aae2fb3b..17fa3b5e 100644
--- a/gl/m4/pthread-spin.m4
+++ b/gl/m4/pthread-spin.m4
@@ -1,6 +1,6 @@
 # pthread-spin.m4
 # serial 8
-dnl Copyright (C) 2019-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2019-2026 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.
diff --git a/gl/m4/pthread_h.m4 b/gl/m4/pthread_h.m4
index bb921386..f01dc3d3 100644
--- a/gl/m4/pthread_h.m4
+++ b/gl/m4/pthread_h.m4
@@ -1,6 +1,6 @@
 # pthread_h.m4
 # serial 11
-dnl Copyright (C) 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2009-2026 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.
diff --git a/gl/m4/pthread_rwlock_rdlock.m4 b/gl/m4/pthread_rwlock_rdlock.m4
index aec9f076..c16c781d 100644
--- a/gl/m4/pthread_rwlock_rdlock.m4
+++ b/gl/m4/pthread_rwlock_rdlock.m4
@@ -1,6 +1,6 @@
 # pthread_rwlock_rdlock.m4
 # serial 8
-dnl Copyright (C) 2017-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2017-2026 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.
@@ -32,7 +32,7 @@ dnl https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlock_rd
 dnl but this test verifies the guarantee regardless of TPS and regardless of
 dnl scheduling policy.
 dnl Glibc does not provide this guarantee (and never will on Linux), see
-dnl https://sourceware.org/bugzilla/show_bug.cgi?id=13701
+dnl https://sourceware.org/PR13701
 dnl https://bugzilla.redhat.com/show_bug.cgi?id=1410052
 AC_DEFUN([gl_PTHREAD_RWLOCK_RDLOCK_PREFER_WRITER],
 [
diff --git a/gl/m4/realloc.m4 b/gl/m4/realloc.m4
index 67c1476b..8938db92 100644
--- a/gl/m4/realloc.m4
+++ b/gl/m4/realloc.m4
@@ -1,6 +1,6 @@
 # realloc.m4
-# serial 39.1
+# serial 40
-dnl Copyright (C) 2007, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007, 2009-2026 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.
diff --git a/gl/m4/reallocarray.m4 b/gl/m4/reallocarray.m4
index 3970d9e1..e789967c 100644
--- a/gl/m4/reallocarray.m4
+++ b/gl/m4/reallocarray.m4
@@ -1,6 +1,6 @@
 # reallocarray.m4
 # serial 7
-dnl Copyright (C) 2017-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2017-2026 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.
diff --git a/gl/m4/regex.m4 b/gl/m4/regex.m4
index 49a8059f..45a10490 100644
--- a/gl/m4/regex.m4
+++ b/gl/m4/regex.m4
@@ -1,6 +1,6 @@
 # regex.m4
 # serial 81
-dnl Copyright (C) 1996-2001, 2003-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 1996-2001, 2003-2026 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.
diff --git a/gl/m4/sched_h.m4 b/gl/m4/sched_h.m4
index 1ffd465f..92ebe1b7 100644
--- a/gl/m4/sched_h.m4
+++ b/gl/m4/sched_h.m4
@@ -1,6 +1,6 @@
 # sched_h.m4
 # serial 16
-dnl Copyright (C) 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2008-2026 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.
diff --git a/gl/m4/servent.m4 b/gl/m4/servent.m4
index ba6ebd1d..97bcad0f 100644
--- a/gl/m4/servent.m4
+++ b/gl/m4/servent.m4
@@ -1,6 +1,6 @@
 # servent.m4
 # serial 5
-dnl Copyright (C) 2008, 2010-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2008, 2010-2026 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.
diff --git a/gl/m4/setenv.m4 b/gl/m4/setenv.m4
index 727e35af..5faf28d2 100644
--- a/gl/m4/setenv.m4
+++ b/gl/m4/setenv.m4
@@ -1,6 +1,6 @@
 # setenv.m4
-# serial 35
+# serial 36
-dnl Copyright (C) 2001-2004, 2006-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2001-2004, 2006-2026 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.
@@ -85,8 +85,6 @@ AC_DEFUN([gl_FUNC_UNSETENV],
      [AC_COMPILE_IFELSE(
         [AC_LANG_PROGRAM(
            [[
-#undef _BSD
-#define _BSD 1 /* unhide unsetenv declaration in OSF/1 5.1 <stdlib.h> */
 #include <stdlib.h>
 extern
 #ifdef __cplusplus
diff --git a/gl/m4/setlocale_null.m4 b/gl/m4/setlocale_null.m4
index 3c8b693e..b6727245 100644
--- a/gl/m4/setlocale_null.m4
+++ b/gl/m4/setlocale_null.m4
@@ -1,6 +1,6 @@
 # setlocale_null.m4
-# serial 10
+# serial 11
-dnl Copyright (C) 2019-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2019-2026 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.
@@ -32,8 +32,8 @@ AC_DEFUN_ONCE([gl_FUNC_SETLOCALE_NULL],
          [gl_cv_func_setlocale_null_all_mtsafe=yes],
          [gl_cv_func_setlocale_null_all_mtsafe=no])
        ;;
-       # Guess yes on glibc, HP-UX, IRIX, Solaris, native Windows.
+       # Guess yes on glibc, HP-UX, Solaris, native Windows.
-       *-gnu* | gnu* | hpux* | irix* | solaris* | mingw* | windows*)
+       *-gnu* | gnu* | hpux* | solaris* | mingw* | windows*)
         gl_cv_func_setlocale_null_all_mtsafe=yes ;;
       # If we don't know, obey --enable-cross-guesses.
       *)
@@ -63,8 +63,8 @@ AC_DEFUN_ONCE([gl_FUNC_SETLOCALE_NULL],
       # Guess no on OpenBSD, AIX.
       openbsd* | aix*)
         gl_cv_func_setlocale_null_one_mtsafe=no ;;
-       # Guess yes on glibc, musl libc, macOS, FreeBSD, NetBSD, HP-UX, IRIX, Solaris, Haiku, Cygwin, native Windows.
+       # Guess yes on glibc, musl libc, macOS, FreeBSD, NetBSD, HP-UX, Solaris, Haiku, Cygwin, native Windows.
-       *-gnu* | gnu* | *-musl* | midipix* | darwin* | freebsd* | midnightbsd* | netbsd* | hpux* | irix* | solaris* | haiku* | cygwin* | mingw* | windows*)
+       *-gnu* | gnu* | *-musl* | midipix* | darwin* | freebsd* | midnightbsd* | netbsd* | hpux* | solaris* | haiku* | cygwin* | mingw* | windows*)
         gl_cv_func_setlocale_null_one_mtsafe=yes ;;
       # If we don't know, obey --enable-cross-guesses.
       *)
diff --git a/gl/m4/sha256.m4 b/gl/m4/sha256.m4
index 30e8deeb..a9bd7857 100644
--- a/gl/m4/sha256.m4
+++ b/gl/m4/sha256.m4
@@ -1,6 +1,6 @@
 # sha256.m4
 # serial 8
-dnl Copyright (C) 2005, 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2005, 2008-2026 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.
diff --git a/gl/m4/size_max.m4 b/gl/m4/size_max.m4
index b0460d45..b7a5153a 100644
--- a/gl/m4/size_max.m4
+++ b/gl/m4/size_max.m4
@@ -1,6 +1,6 @@
 # size_max.m4
 # serial 12
-dnl Copyright (C) 2003, 2005-2006, 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2003, 2005-2006, 2008-2026 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.
diff --git a/gl/m4/snprintf.m4 b/gl/m4/snprintf.m4
index 2c50cee9..6de225c2 100644
--- a/gl/m4/snprintf.m4
+++ b/gl/m4/snprintf.m4
@@ -1,6 +1,6 @@
 # snprintf.m4
 # serial 7
-dnl Copyright (C) 2002-2004, 2007-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2002-2004, 2007-2026 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.
diff --git a/gl/m4/socketlib.m4 b/gl/m4/socketlib.m4
index e3509f81..f62ffcfd 100644
--- a/gl/m4/socketlib.m4
+++ b/gl/m4/socketlib.m4
@@ -1,6 +1,6 @@
 # socketlib.m4
 # serial 4
-dnl Copyright (C) 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2008-2026 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.
diff --git a/gl/m4/sockets.m4 b/gl/m4/sockets.m4
index 54f4dc79..95800d2e 100644
--- a/gl/m4/sockets.m4
+++ b/gl/m4/sockets.m4
@@ -1,6 +1,6 @@
 # sockets.m4
 # serial 7
-dnl Copyright (C) 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2008-2026 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.
diff --git a/gl/m4/socklen.m4 b/gl/m4/socklen.m4
index a8ac25b1..e5156511 100644
--- a/gl/m4/socklen.m4
+++ b/gl/m4/socklen.m4
@@ -1,6 +1,6 @@
 # socklen.m4
-# serial 11
+# serial 13
-dnl Copyright (C) 2005-2007, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2005-2007, 2009-2026 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.
@@ -11,7 +11,7 @@ dnl From Albert Chin, Windows fixes from Simon Josefsson.
 dnl Check for socklen_t: historically on BSD it is an int, and in
 dnl POSIX 1g it is a type of its own, but some platforms use different
 dnl types for the argument to getsockopt, getpeername, etc.:
-dnl HP-UX 10.20, IRIX 6.5, OSF/1 4.0, Interix 3.5, BeOS.
+dnl HP-UX 10.20, Interix 3.5, BeOS.
 dnl So we have to test to find something that will work.
 AC_DEFUN([gl_TYPE_SOCKLEN_T],
diff --git a/gl/m4/sockpfaf.m4 b/gl/m4/sockpfaf.m4
index 08ce843d..6379766d 100644
--- a/gl/m4/sockpfaf.m4
+++ b/gl/m4/sockpfaf.m4
@@ -1,6 +1,6 @@
 # sockpfaf.m4
 # serial 11
-dnl Copyright (C) 2004, 2006, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2004, 2006, 2009-2026 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.
diff --git a/gl/m4/ssize_t.m4 b/gl/m4/ssize_t.m4
index a2ffd6fc..8710cb72 100644
--- a/gl/m4/ssize_t.m4
+++ b/gl/m4/ssize_t.m4
@@ -1,6 +1,6 @@
 # ssize_t.m4
 # serial 6
-dnl Copyright (C) 2001-2003, 2006, 2010-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2001-2003, 2006, 2010-2026 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.
diff --git a/gl/m4/stat-time.m4 b/gl/m4/stat-time.m4
index 4aa24e7f..10eb1dfa 100644
--- a/gl/m4/stat-time.m4
+++ b/gl/m4/stat-time.m4
@@ -1,6 +1,6 @@
 # stat-time.m4
 # serial 1
-dnl Copyright (C) 1998-1999, 2001, 2003, 2005-2007, 2009-2025 Free Software
+dnl Copyright (C) 1998-1999, 2001, 2003, 2005-2007, 2009-2026 Free Software
 dnl Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
diff --git a/gl/m4/stat.m4 b/gl/m4/stat.m4
index 66876305..3764ec0b 100644
--- a/gl/m4/stat.m4
+++ b/gl/m4/stat.m4
@@ -1,6 +1,6 @@
 # stat.m4
 # serial 21
-dnl Copyright (C) 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2009-2026 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.
diff --git a/gl/m4/std-gnu11.m4 b/gl/m4/std-gnu11.m4
index 762764e0..0868a43a 100644
--- a/gl/m4/std-gnu11.m4
+++ b/gl/m4/std-gnu11.m4
@@ -16,7 +16,7 @@ m4_ifndef([_AC_C_C23_OPTIONS], [
 m4_version_prereq([2.70], [], [
-# Copyright (C) 2001-2025 Free Software Foundation, Inc.
+# Copyright (C) 2001-2026 Free Software Foundation, Inc.
 # This file is part of Autoconf.  This program is free
 # software; you can redistribute it and/or modify it under the
@@ -777,7 +777,7 @@ AC_DEFUN([_AC_CXX_CXX11_TEST_BODY],
 }
 {
  // Unicode literals
-  char const *utf8 = u8"UTF-8 string \u2500";
+  auto const *utf8 = u8"UTF-8 string \u2500"; // This is portable to C++20.
  char16_t const *utf16 = u"UTF-8 string \u2500";
  char32_t const *utf32 = U"UTF-32 string \u2500";
 }
diff --git a/gl/m4/stdalign.m4 b/gl/m4/stdalign.m4
index 885feafd..7177d034 100644
--- a/gl/m4/stdalign.m4
+++ b/gl/m4/stdalign.m4
@@ -1,6 +1,6 @@
 # stdalign.m4
 # serial 3
-dnl Copyright 2011-2025 Free Software Foundation, Inc.
+dnl Copyright 2011-2026 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.
@@ -30,7 +30,7 @@ AC_DEFUN([gl_ALIGNASOF],
            /* Test that alignof yields a result consistent with offsetof.
               This catches GCC bug 52023
-               <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52023>.  */
+               <https://gcc.gnu.org/PR52023>.  */
            #ifdef __cplusplus
               template <class t> struct alignof_helper { char a; t b; };
            # define ao(type) offsetof (alignof_helper<type>, b)
@@ -82,8 +82,8 @@ AC_DEFUN([gl_ALIGNASOF],
   References:
   ISO C23 (latest free draft
-   <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf>)
+   <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3220.pdf>)
-   sections 6.5.3.4, 6.7.5, 7.15.
+   sections 6.2.8, 6.7.6.
   C++11 (latest free draft
   <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2011/n3242.pdf>)
   section 18.10. */
@@ -103,7 +103,7 @@ AC_DEFUN([gl_ALIGNASOF],
   want to be portable to HP-UX 10.20 cc and AIX 3.2.5 xlc.  */
 /* GCC releases before GCC 4.9 had a bug in _Alignof.  See GCC bug 52023
-   <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52023>.
+   <https://gcc.gnu.org/PR52023>.
   clang versions < 8.0.0 have the same bug.
   IBM XL C V16.1.0 cc (non-clang) has the same bug.  */
 #  if (!defined __STDC_VERSION__ || __STDC_VERSION__ < 201112 \
diff --git a/gl/m4/stdckdint_h.m4 b/gl/m4/stdckdint_h.m4
index d269faa5..eb8c858a 100644
--- a/gl/m4/stdckdint_h.m4
+++ b/gl/m4/stdckdint_h.m4
@@ -1,6 +1,6 @@
 # stdckdint_h.m4
 # serial 1
-dnl Copyright 2025 Free Software Foundation, Inc.
+dnl Copyright 2025-2026 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.
diff --git a/gl/m4/stddef_h.m4 b/gl/m4/stddef_h.m4
index 127ec05b..299472b1 100644
--- a/gl/m4/stddef_h.m4
+++ b/gl/m4/stddef_h.m4
@@ -1,6 +1,6 @@
 # stddef_h.m4
 # serial 23
-dnl Copyright (C) 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2009-2026 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.
@@ -85,7 +85,7 @@ AC_DEFUN_ONCE([gl_STDDEF_H],
  dnl Provide gl_unreachable() unconditionally.
  GL_GENERATE_STDDEF_H=true
-  dnl https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114869
+  dnl https://gcc.gnu.org/PR114869
  AC_CACHE_CHECK([whether nullptr_t needs <stddef.h>],
    [gl_cv_nullptr_t_needs_stddef],
    [AC_COMPILE_IFELSE([AC_LANG_DEFINES_PROVIDED[nullptr_t x;]],
@@ -96,7 +96,7 @@ AC_DEFUN_ONCE([gl_STDDEF_H],
    GL_GENERATE_STDDEF_H=true
  fi
-  dnl https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114870
+  dnl https://gcc.gnu.org/PR114870
  dnl affects GCC 13.3 and 14.2.
  AC_CACHE_CHECK([whether <stddef.h> is idempotent],
    [gl_cv_stddef_idempotent],
diff --git a/gl/m4/stdint.m4 b/gl/m4/stdint.m4
index 2d69088b..410da153 100644
--- a/gl/m4/stdint.m4
+++ b/gl/m4/stdint.m4
@@ -1,6 +1,6 @@
 # stdint.m4
-# serial 64
+# serial 65
-dnl Copyright (C) 2001-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2001-2026 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.
@@ -391,9 +391,9 @@ AC_DEFUN([gl_STDINT_BITSIZEOF],
      ])
    eval result=\$gl_cv_bitsizeof_${gltype}
    if test $result = unknown; then
-      dnl Use a nonempty default, because some compilers, such as IRIX 5 cc,
+      dnl Use a nonempty default, because some old compilers do a syntax check
-      dnl do a syntax check even on unused #if conditions and give an error
+      dnl even on unused #if conditions and give an error on valid C code like
-      dnl on valid C code like this:
+      dnl this:
      dnl   #if 0
      dnl   # if  > 32
      dnl   # endif
diff --git a/gl/m4/stdint_h.m4 b/gl/m4/stdint_h.m4
index d4f1acdd..7f60af20 100644
--- a/gl/m4/stdint_h.m4
+++ b/gl/m4/stdint_h.m4
@@ -1,6 +1,6 @@
 # stdint_h.m4
 # serial 9
-dnl Copyright (C) 1997-2004, 2006, 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 1997-2004, 2006, 2008-2026 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.
diff --git a/gl/m4/stdio_h.m4 b/gl/m4/stdio_h.m4
index 71d86180..9d4126f5 100644
--- a/gl/m4/stdio_h.m4
+++ b/gl/m4/stdio_h.m4
@@ -1,6 +1,6 @@
 # stdio_h.m4
 # serial 75
-dnl Copyright (C) 2007-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007-2026 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.
diff --git a/gl/m4/stdlib_h.m4 b/gl/m4/stdlib_h.m4
index 2d25da37..f35d6611 100644
--- a/gl/m4/stdlib_h.m4
+++ b/gl/m4/stdlib_h.m4
@@ -1,6 +1,6 @@
 # stdlib_h.m4
-# serial 84
+# serial 86
-dnl Copyright (C) 2007-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007-2026 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.
@@ -205,7 +205,6 @@ AC_DEFUN([gl_STDLIB_H_DEFAULTS],
  HAVE_PTSNAME_R=1;          AC_SUBST([HAVE_PTSNAME_R])
  HAVE_QSORT_R=1;            AC_SUBST([HAVE_QSORT_R])
  HAVE_RANDOM=1;             AC_SUBST([HAVE_RANDOM])
-  HAVE_RANDOM_H=1;           AC_SUBST([HAVE_RANDOM_H])
  HAVE_RANDOM_R=1;           AC_SUBST([HAVE_RANDOM_R])
  HAVE_REALLOCARRAY=1;       AC_SUBST([HAVE_REALLOCARRAY])
  HAVE_REALPATH=1;           AC_SUBST([HAVE_REALPATH])
@@ -224,6 +223,7 @@ AC_DEFUN([gl_STDLIB_H_DEFAULTS],
  HAVE_STRTOULL=1;           AC_SUBST([HAVE_STRTOULL])
  HAVE_STRUCT_RANDOM_DATA=1; AC_SUBST([HAVE_STRUCT_RANDOM_DATA])
  HAVE_SYS_LOADAVG_H=0;      AC_SUBST([HAVE_SYS_LOADAVG_H])
+  HAVE_SYS_PROCESS_H=0;      AC_SUBST([HAVE_SYS_PROCESS_H])
  HAVE_UNLOCKPT=1;           AC_SUBST([HAVE_UNLOCKPT])
  HAVE_DECL_UNSETENV=1;      AC_SUBST([HAVE_DECL_UNSETENV])
  REPLACE__EXIT=0;           AC_SUBST([REPLACE__EXIT])
diff --git a/gl/m4/strcasecmp.m4 b/gl/m4/strcasecmp.m4
index eb4345d9..f9f90928 100644
--- a/gl/m4/strcasecmp.m4
+++ b/gl/m4/strcasecmp.m4
@@ -1,6 +1,6 @@
 # strcasecmp.m4
 # serial 3
-dnl Copyright (C) 2002-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2002-2026 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.
diff --git a/gl/m4/strcasestr.m4 b/gl/m4/strcasestr.m4
index eb2862f1..f56eed58 100644
--- a/gl/m4/strcasestr.m4
+++ b/gl/m4/strcasestr.m4
@@ -1,6 +1,6 @@
 # strcasestr.m4
 # serial 29
-dnl Copyright (C) 2005, 2007-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2005, 2007-2026 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.
@@ -22,8 +22,8 @@ AC_DEFUN([gl_FUNC_STRCASESTR_SIMPLE],
    if test $REPLACE_MEMCHR = 1; then
      REPLACE_STRCASESTR=1
    else
-      dnl Detect https://sourceware.org/bugzilla/show_bug.cgi?id=12092
+      dnl Detect https://sourceware.org/PR12092
-      dnl and https://sourceware.org/bugzilla/show_bug.cgi?id=23637.
+      dnl and https://sourceware.org/PR23637.
      AC_CACHE_CHECK([whether strcasestr works],
        [gl_cv_func_strcasestr_works_always],
        [AC_RUN_IFELSE(
diff --git a/gl/m4/strerror.m4 b/gl/m4/strerror.m4
index c8b3b207..9bb60c3f 100644
--- a/gl/m4/strerror.m4
+++ b/gl/m4/strerror.m4
@@ -1,6 +1,6 @@
 # strerror.m4
 # serial 25
-dnl Copyright (C) 2002, 2007-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2002, 2007-2026 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.
diff --git a/gl/m4/string_h.m4 b/gl/m4/string_h.m4
index fc73603a..2a6e4db4 100644
--- a/gl/m4/string_h.m4
+++ b/gl/m4/string_h.m4
@@ -1,6 +1,6 @@
 # string_h.m4
-# serial 44.1
+# serial 46
-dnl Copyright (C) 2007-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007-2026 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.
@@ -63,6 +63,7 @@ AC_DEFUN([gl_STRING_H_REQUIRE_DEFAULTS],
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_STPNCPY])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_STRCHRNUL])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_STRDUP])
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_STRINGEQ])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_STRNCAT])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_STRNCPY])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_STRNDUP])
@@ -115,6 +116,7 @@ AC_DEFUN([gl_STRING_H_DEFAULTS],
  HAVE_EXPLICIT_BZERO=1;        AC_SUBST([HAVE_EXPLICIT_BZERO])
  HAVE_FFSL=1;                  AC_SUBST([HAVE_FFSL])
  HAVE_FFSLL=1;                 AC_SUBST([HAVE_FFSLL])
+  HAVE_DECL_MEMEQ=0;            AC_SUBST([HAVE_DECL_MEMEQ])
  HAVE_DECL_MEMMEM=1;           AC_SUBST([HAVE_DECL_MEMMEM])
  HAVE_MEMPCPY=1;               AC_SUBST([HAVE_MEMPCPY])
  HAVE_MEMSET_EXPLICIT=1;       AC_SUBST([HAVE_MEMSET_EXPLICIT])
@@ -124,6 +126,7 @@ AC_DEFUN([gl_STRING_H_DEFAULTS],
  HAVE_STPNCPY=1;               AC_SUBST([HAVE_STPNCPY])
  HAVE_STRCHRNUL=1;             AC_SUBST([HAVE_STRCHRNUL])
  HAVE_DECL_STRDUP=1;           AC_SUBST([HAVE_DECL_STRDUP])
+  HAVE_DECL_STREQ=0;            AC_SUBST([HAVE_DECL_STREQ])
  HAVE_DECL_STRNDUP=1;          AC_SUBST([HAVE_DECL_STRNDUP])
  HAVE_DECL_STRNLEN=1;          AC_SUBST([HAVE_DECL_STRNLEN])
  HAVE_STRPBRK=1;               AC_SUBST([HAVE_STRPBRK])
diff --git a/gl/m4/stringeq.m4 b/gl/m4/stringeq.m4
new file mode 100644
index 00000000..ffea8afc
--- /dev/null
+++ b/gl/m4/stringeq.m4
@@ -0,0 +1,25 @@
+# stringeq.m4
+# serial 1
+dnl Copyright (C) 2025-2026 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 This file is offered as-is, without any warranty.
+AC_DEFUN([gl_FUNC_STREQ],
+[
+  AC_REQUIRE([gl_STRING_H_DEFAULTS])
+  AC_CHECK_DECLS_ONCE([streq])
+  if test $ac_cv_have_decl_streq != no; then
+    HAVE_DECL_STREQ=1
+  fi
+])
+AC_DEFUN([gl_FUNC_MEMEQ],
+[
+  AC_REQUIRE([gl_STRING_H_DEFAULTS])
+  AC_CHECK_DECLS_ONCE([memeq])
+  if test $ac_cv_have_decl_memeq != no; then
+    HAVE_DECL_MEMEQ=1
+  fi
+])
diff --git a/gl/m4/strings_h.m4 b/gl/m4/strings_h.m4
index 18f30d4a..aec4f715 100644
--- a/gl/m4/strings_h.m4
+++ b/gl/m4/strings_h.m4
@@ -1,6 +1,6 @@
 # strings_h.m4
 # serial 14
-dnl Copyright (C) 2007, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007, 2009-2026 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.
diff --git a/gl/m4/strncasecmp.m4 b/gl/m4/strncasecmp.m4
index c7c8b240..4314b603 100644
--- a/gl/m4/strncasecmp.m4
+++ b/gl/m4/strncasecmp.m4
@@ -1,6 +1,6 @@
 # strncasecmp.m4
 # serial 2
-dnl Copyright (C) 2002-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2002-2026 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.
diff --git a/gl/m4/strncpy.m4 b/gl/m4/strncpy.m4
index 57876171..b94abede 100644
--- a/gl/m4/strncpy.m4
+++ b/gl/m4/strncpy.m4
@@ -1,6 +1,6 @@
 # strncpy.m4
 # serial 1
-dnl Copyright (C) 2002-2004, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2002-2004, 2009-2026 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.
diff --git a/gl/m4/strsep.m4 b/gl/m4/strsep.m4
index b018ff88..6afd34a9 100644
--- a/gl/m4/strsep.m4
+++ b/gl/m4/strsep.m4
@@ -1,6 +1,6 @@
 # strsep.m4
 # serial 11
-dnl Copyright (C) 2002-2004, 2007, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2002-2004, 2007, 2009-2026 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.
diff --git a/gl/m4/strstr.m4 b/gl/m4/strstr.m4
index 1b5ef6c1..3a9e9c60 100644
--- a/gl/m4/strstr.m4
+++ b/gl/m4/strstr.m4
@@ -1,6 +1,6 @@
 # strstr.m4
 # serial 25
-dnl Copyright (C) 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2008-2026 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.
@@ -14,8 +14,8 @@ AC_DEFUN([gl_FUNC_STRSTR_SIMPLE],
  if test $REPLACE_MEMCHR = 1; then
    REPLACE_STRSTR=1
  else
-    dnl Detect https://sourceware.org/bugzilla/show_bug.cgi?id=12092
+    dnl Detect https://sourceware.org/PR12092
-    dnl and https://sourceware.org/bugzilla/show_bug.cgi?id=23637.
+    dnl and https://sourceware.org/PR23637.
    AC_CACHE_CHECK([whether strstr works],
      [gl_cv_func_strstr_works_always],
      [AC_RUN_IFELSE(
diff --git a/gl/m4/sys_cdefs_h.m4 b/gl/m4/sys_cdefs_h.m4
index d72796ca..a1398a29 100644
--- a/gl/m4/sys_cdefs_h.m4
+++ b/gl/m4/sys_cdefs_h.m4
@@ -1,6 +1,6 @@
 # sys_cdefs_h.m4 - Is <sys/cdefs.h> compatible enough with glibc?
 # serial 2
-dnl Copyright 2024-2025 Free Software Foundation, Inc.
+dnl Copyright 2024-2026 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
diff --git a/gl/m4/sys_socket_h.m4 b/gl/m4/sys_socket_h.m4
index fb69209b..cdc374e4 100644
--- a/gl/m4/sys_socket_h.m4
+++ b/gl/m4/sys_socket_h.m4
@@ -1,6 +1,6 @@
 # sys_socket_h.m4
-# serial 31
+# serial 32
-dnl Copyright (C) 2005-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2005-2026 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -13,17 +13,6 @@ AC_DEFUN_ONCE([gl_SYS_SOCKET_H],
  AC_REQUIRE([gl_SYS_SOCKET_H_DEFAULTS])
  AC_REQUIRE([AC_CANONICAL_HOST])
-  dnl On OSF/1, the functions recv(), send(), recvfrom(), sendto() have
-  dnl old-style declarations (with return type 'int' instead of 'ssize_t')
-  dnl unless _POSIX_PII_SOCKET is defined.
-  case "$host_os" in
-    osf*)
-      AC_DEFINE([_POSIX_PII_SOCKET], [1],
-        [Define to 1 in order to get the POSIX compatible declarations
-         of socket functions.])
-      ;;
-  esac
  GL_GENERATE_SYS_SOCKET_H=false
  AC_CACHE_CHECK([whether <sys/socket.h> is self-contained],
    [gl_cv_header_sys_socket_h_selfcontained],
diff --git a/gl/m4/sys_stat_h.m4 b/gl/m4/sys_stat_h.m4
index fdcc8954..04dfce7e 100644
--- a/gl/m4/sys_stat_h.m4
+++ b/gl/m4/sys_stat_h.m4
@@ -1,6 +1,6 @@
 # sys_stat_h.m4
-# serial 42   -*- Autoconf -*-
+# serial 44   -*- Autoconf -*-
-dnl Copyright (C) 2006-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2006-2026 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.
diff --git a/gl/m4/sys_types_h.m4 b/gl/m4/sys_types_h.m4
index e99fdcc6..b284e08e 100644
--- a/gl/m4/sys_types_h.m4
+++ b/gl/m4/sys_types_h.m4
@@ -1,6 +1,6 @@
 # sys_types_h.m4
 # serial 15
-dnl Copyright (C) 2011-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2011-2026 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.
diff --git a/gl/m4/sys_uio_h.m4 b/gl/m4/sys_uio_h.m4
index eb0e8424..59496e01 100644
--- a/gl/m4/sys_uio_h.m4
+++ b/gl/m4/sys_uio_h.m4
@@ -1,6 +1,6 @@
 # sys_uio_h.m4
 # serial 3
-dnl Copyright (C) 2011-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2011-2026 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.
diff --git a/gl/m4/threadlib.m4 b/gl/m4/threadlib.m4
index 333c8fe0..bdea4b97 100644
--- a/gl/m4/threadlib.m4
+++ b/gl/m4/threadlib.m4
@@ -1,6 +1,6 @@
 # threadlib.m4
-# serial 45.1
+# serial 49
-dnl Copyright (C) 2005-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2005-2026 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.
@@ -57,16 +57,6 @@ AC_DEFUN([gl_ANYTHREADLIB_EARLY],
 [
  AC_REQUIRE([AC_CANONICAL_HOST])
  if test -z "$gl_anythreadlib_early_done"; then
-    AS_CASE([$host_os],
-      [osf*],
-       [# On OSF/1, the compiler needs the flag -D_REENTRANT so that it
-        # groks <pthread.h>. cc also understands the flag -pthread, but
-        # we do not use it because 1. gcc-2.95 does not understand -pthread,
-        # 2. putting a flag into CPPFLAGS that has an effect on the linker
-        # causes the AC_LINK_IFELSE test below to succeed unexpectedly,
-        # leading to wrong values of LIBTHREAD and LTLIBTHREAD.
-        CPPFLAGS="$CPPFLAGS -D_REENTRANT"
-       ])
    # Some systems optimize for single-threaded programs by default, and
    # need special flags to disable these optimizations. For example, the
    # definition of errno in <errno.h>.
@@ -190,17 +180,13 @@ AC_DEFUN([gl_PTHREADLIB_BODY],
    gl_pthread_api=no
    LIBPTHREAD=
    LIBPMULTITHREAD=
-    # On OSF/1, the compiler needs the flag -pthread or -D_REENTRANT so that
-    # it groks <pthread.h>. It is added above, in gl_ANYTHREADLIB_EARLY.
    AC_CHECK_HEADER([pthread.h],
      [gl_have_pthread_h=yes], [gl_have_pthread_h=no])
    AS_IF([test "$gl_have_pthread_h" = yes], [
      # Other possible tests:
      #   -lpthreads (FSU threads, PCthreads)
      #   -lgthreads
-      # Test whether both pthread_mutex_lock and pthread_mutexattr_init exist
+      # Test whether both pthread_mutex_lock exists in libc.
-      # in libc. IRIX 6.5 has the first one in both libc and libpthread, but
-      # the second one only in libpthread, and lock.c needs it.
      #
      # If -pthread works, prefer it to -lpthread, since Ubuntu 14.04
      # needs -pthread for some reason.  See:
@@ -212,10 +198,8 @@ AC_DEFUN([gl_PTHREADLIB_BODY],
          [AC_LANG_PROGRAM(
             [[#include <pthread.h>
               pthread_mutex_t m;
-               pthread_mutexattr_t ma;
             ]],
-             [[pthread_mutex_lock (&m);
+             [[pthread_mutex_lock (&m);]])],
-               pthread_mutexattr_init (&ma);]])],
          [gl_pthread_api=yes
           LIBPTHREAD=$gl_pthread
           LIBPMULTITHREAD=$gl_pthread])
@@ -244,8 +228,7 @@ AC_DEFUN([gl_PTHREADLIB_BODY],
         ])
      echo "$as_me:__oline__: gl_pthread_in_glibc=$gl_pthread_in_glibc" >&AS_MESSAGE_LOG_FD
-      # Test for libpthread by looking for pthread_kill. (Not pthread_self,
+      # Test for libpthread by looking for pthread_kill.
-      # since it is defined as a macro on OSF/1.)
      AS_IF([test $gl_pthread_api = yes && test -z "$LIBPTHREAD"], [
        # The program links fine without libpthread. But it may actually
        # need to link with libpthread in order to create multiple threads.
@@ -451,18 +434,19 @@ AC_DEFUN([gl_THREADLIB_EARLY_BODY],
  dnl gl_use_winpthreads_default defaults to "no", because in mingw 10, like
  dnl in mingw 5, the use of libwinpthread still makes test-pthread-tss crash.
  m4_divert_text([DEFAULTS], [gl_use_winpthreads_default=no])
+  dnl Don't display the --disable-threads option
+  dnl   - if the package builds one or more libraries, because libraries must
+  dnl     always be multithread-safe (as far as possible),
+  dnl   - if the package defines gl_THREADLIB_DEFAULT_NO, because the option
+  dnl     would then be a no-op.
  AC_ARG_ENABLE([threads],
-AS_HELP_STRING([[--enable-threads={isoc|posix|isoc+posix|windows}]], [specify multithreading API])m4_ifdef([gl_THREADLIB_DEFAULT_NO], [], [
+AS_HELP_STRING([[--enable-threads={isoc|posix|isoc+posix|windows}]], [specify multithreading API])m4_ifdef([LT_INIT], [], [m4_ifdef([gl_THREADLIB_DEFAULT_NO], [], [
-AS_HELP_STRING([[--disable-threads]], [build without multithread safety])]),
+AS_HELP_STRING([[--disable-threads]], [build without multithread safety])])]),
    [gl_use_threads=$enableval],
    [if test -n "$gl_use_threads_default"; then
       gl_use_threads="$gl_use_threads_default"
     else
       AS_CASE([$host_os],
-         dnl Disable multithreading by default on OSF/1, because it interferes
-         dnl with fork()/exec(): When msgexec is linked with -lpthread, its
-         dnl child process gets an endless segmentation fault inside execvp().
-         [osf*], [gl_use_threads=no],
         dnl Disable multithreading by default on Cygwin 1.5.x, because it has
         dnl bugs that lead to endless loops or crashes. See
         dnl <https://cygwin.com/ml/cygwin/2009-08/msg00283.html>.
@@ -665,13 +649,8 @@ dnl
 dnl HP-UX 11           posix      -lpthread       N (cc) OK
 dnl                                               Y (gcc)
 dnl
-dnl IRIX 6.5           posix      -lpthread       Y      0.5
-dnl
 dnl AIX 4.3,5.1        posix      -lpthread       N      AIX 4: 0.5; AIX 5: OK
 dnl
-dnl OSF/1 4.0,5.1      posix      -pthread (cc)   N      OK
-dnl                               -lpthread (gcc) Y
-dnl
 dnl Cygwin             posix      -lpthread       Y      OK
 dnl
 dnl Mingw              windows                    N      OK
diff --git a/gl/m4/time_h.m4 b/gl/m4/time_h.m4
index f4d8e20f..8d896ea5 100644
--- a/gl/m4/time_h.m4
+++ b/gl/m4/time_h.m4
@@ -1,6 +1,6 @@
 # time_h.m4
 # serial 27
-dnl Copyright (C) 2000-2001, 2003-2007, 2009-2025 Free Software Foundation,
+dnl Copyright (C) 2000-2001, 2003-2007, 2009-2026 Free Software Foundation,
 dnl Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
diff --git a/gl/m4/time_r.m4 b/gl/m4/time_r.m4
index 96f5c5b5..59477e3b 100644
--- a/gl/m4/time_r.m4
+++ b/gl/m4/time_r.m4
@@ -1,6 +1,6 @@
 # time_r.m4
 # serial 1
-dnl Copyright (C) 2003, 2006-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2003, 2006-2026 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.
diff --git a/gl/m4/timegm.m4 b/gl/m4/timegm.m4
index cb6da6da..50a98b25 100644
--- a/gl/m4/timegm.m4
+++ b/gl/m4/timegm.m4
@@ -1,6 +1,6 @@
 # timegm.m4
 # serial 16
-dnl Copyright (C) 2003, 2007, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2003, 2007, 2009-2026 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.
diff --git a/gl/m4/uchar_h.m4 b/gl/m4/uchar_h.m4
index b2309385..20b63b6c 100644
--- a/gl/m4/uchar_h.m4
+++ b/gl/m4/uchar_h.m4
@@ -1,6 +1,6 @@
 # uchar_h.m4
 # serial 32
-dnl Copyright (C) 2019-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2019-2026 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.
diff --git a/gl/m4/ungetc.m4 b/gl/m4/ungetc.m4
index 969b60e8..299c43f2 100644
--- a/gl/m4/ungetc.m4
+++ b/gl/m4/ungetc.m4
@@ -1,6 +1,6 @@
 # ungetc.m4
 # serial 12
-dnl Copyright (C) 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2009-2026 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.
diff --git a/gl/m4/unicase_h.m4 b/gl/m4/unicase_h.m4
index bf5d4c2e..71dccf06 100644
--- a/gl/m4/unicase_h.m4
+++ b/gl/m4/unicase_h.m4
@@ -1,6 +1,6 @@
 # unicase_h.m4
 # serial 1
-dnl Copyright (C) 2023-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2023-2026 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.
diff --git a/gl/m4/unictype_h.m4 b/gl/m4/unictype_h.m4
index 68ddaf6c..ba5a3688 100644
--- a/gl/m4/unictype_h.m4
+++ b/gl/m4/unictype_h.m4
@@ -1,6 +1,6 @@
 # unictype_h.m4
 # serial 4
-dnl Copyright (C) 2023-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2023-2026 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.
diff --git a/gl/m4/uninorm_h.m4 b/gl/m4/uninorm_h.m4
index d416f73b..5ec9ea67 100644
--- a/gl/m4/uninorm_h.m4
+++ b/gl/m4/uninorm_h.m4
@@ -1,6 +1,6 @@
 # uninorm_h.m4
 # serial 1
-dnl Copyright (C) 2023-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2023-2026 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.
diff --git a/gl/m4/unistd_h.m4 b/gl/m4/unistd_h.m4
index 6ec16286..8000e888 100644
--- a/gl/m4/unistd_h.m4
+++ b/gl/m4/unistd_h.m4
@@ -1,6 +1,6 @@
 # unistd_h.m4
 # serial 97
-dnl Copyright (C) 2006-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2006-2026 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.
diff --git a/gl/m4/unitypes_h.m4 b/gl/m4/unitypes_h.m4
index 264e61be..733b9ee2 100644
--- a/gl/m4/unitypes_h.m4
+++ b/gl/m4/unitypes_h.m4
@@ -1,6 +1,6 @@
 # unitypes_h.m4
 # serial 1
-dnl Copyright (C) 2021-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2021-2026 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.
diff --git a/gl/m4/unlocked-io.m4 b/gl/m4/unlocked-io.m4
index 97f43f4b..16ab6e9a 100644
--- a/gl/m4/unlocked-io.m4
+++ b/gl/m4/unlocked-io.m4
@@ -1,6 +1,6 @@
 # unlocked-io.m4
-# serial 16
+# serial 17
-dnl Copyright (C) 1998-2006, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 1998-2006, 2009-2026 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.
@@ -25,6 +25,7 @@ AC_DEFUN([gl_FUNC_GLIBC_UNLOCKED_IO],
  AC_CHECK_DECLS_ONCE([ferror_unlocked])
  AC_CHECK_DECLS_ONCE([fflush_unlocked])
  AC_CHECK_DECLS_ONCE([fgets_unlocked])
+  AC_CHECK_DECLS_ONCE([fileno_unlocked])
  AC_CHECK_DECLS_ONCE([fputc_unlocked])
  AC_CHECK_DECLS_ONCE([fputs_unlocked])
  AC_CHECK_DECLS_ONCE([fread_unlocked])
diff --git a/gl/m4/vararrays.m4 b/gl/m4/vararrays.m4
index 086e409f..3dd8e68f 100644
--- a/gl/m4/vararrays.m4
+++ b/gl/m4/vararrays.m4
@@ -1,6 +1,6 @@
 # vararrays.m4
 # serial 6
-dnl Copyright (C) 2001, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2001, 2009-2026 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.
diff --git a/gl/m4/vasnprintf.m4 b/gl/m4/vasnprintf.m4
index 1d040d6e..4e01fbc9 100644
--- a/gl/m4/vasnprintf.m4
+++ b/gl/m4/vasnprintf.m4
@@ -1,6 +1,6 @@
 # vasnprintf.m4
 # serial 56
-dnl Copyright (C) 2002-2004, 2006-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2002-2004, 2006-2026 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.
diff --git a/gl/m4/vasprintf.m4 b/gl/m4/vasprintf.m4
index 6ea602bd..3e6913e2 100644
--- a/gl/m4/vasprintf.m4
+++ b/gl/m4/vasprintf.m4
@@ -1,6 +1,6 @@
 # vasprintf.m4
 # serial 6
-dnl Copyright (C) 2002-2003, 2006-2007, 2009-2025 Free Software Foundation,
+dnl Copyright (C) 2002-2003, 2006-2007, 2009-2026 Free Software Foundation,
 dnl Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
diff --git a/gl/m4/visibility.m4 b/gl/m4/visibility.m4
index c2cd38d0..55ceb672 100644
--- a/gl/m4/visibility.m4
+++ b/gl/m4/visibility.m4
@@ -1,6 +1,6 @@
 # visibility.m4
 # serial 9
-dnl Copyright (C) 2005, 2008, 2010-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2005, 2008, 2010-2026 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.
diff --git a/gl/m4/vsnprintf.m4 b/gl/m4/vsnprintf.m4
index 68ab757d..df767486 100644
--- a/gl/m4/vsnprintf.m4
+++ b/gl/m4/vsnprintf.m4
@@ -1,6 +1,6 @@
 # vsnprintf.m4
 # serial 7
-dnl Copyright (C) 2002-2004, 2007-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2002-2004, 2007-2026 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.
diff --git a/gl/m4/warn-on-use.m4 b/gl/m4/warn-on-use.m4
index 73cf16fb..3765368c 100644
--- a/gl/m4/warn-on-use.m4
+++ b/gl/m4/warn-on-use.m4
@@ -1,6 +1,6 @@
 # warn-on-use.m4
 # serial 11
-dnl Copyright (C) 2010-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2010-2026 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.
diff --git a/gl/m4/wchar_h.m4 b/gl/m4/wchar_h.m4
index 722fcfc2..42338a00 100644
--- a/gl/m4/wchar_h.m4
+++ b/gl/m4/wchar_h.m4
@@ -1,6 +1,6 @@
 # wchar_h.m4
-# serial 65
+# serial 66
-dnl Copyright (C) 2007-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2007-2026 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.
@@ -65,8 +65,8 @@ dnl Check whether <wchar.h> is usable at all.
 AC_DEFUN([gl_WCHAR_H_INLINE_OK],
 [
  dnl Test whether <wchar.h> suffers due to the transition from '__inline' to
-  dnl 'gnu_inline'. See <https://sourceware.org/bugzilla/show_bug.cgi?id=4022>
+  dnl 'gnu_inline'. See <https://sourceware.org/PR4022>
-  dnl and <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42440>. In summary,
+  dnl and <https://gcc.gnu.org/PR42440>. In summary,
  dnl glibc version 2.5 or older, together with gcc version 4.3 or newer and
  dnl the option -std=c99 or -std=gnu99, leads to a broken <wchar.h>.
  AC_REQUIRE([AC_CANONICAL_HOST])
@@ -239,7 +239,7 @@ AC_DEFUN([gl_WCHAR_H_DEFAULTS],
  HAVE_WCSTOK=1;        AC_SUBST([HAVE_WCSTOK])
  HAVE_WCSWIDTH=1;      AC_SUBST([HAVE_WCSWIDTH])
  HAVE_WCSFTIME=1;      AC_SUBST([HAVE_WCSFTIME])
-  HAVE_DECL_WCTOB=1;    AC_SUBST([HAVE_DECL_WCTOB])
+  HAVE_WCTOB=1;         AC_SUBST([HAVE_WCTOB])
  HAVE_DECL_WCSDUP=1;   AC_SUBST([HAVE_DECL_WCSDUP])
  HAVE_DECL_WCWIDTH=1;  AC_SUBST([HAVE_DECL_WCWIDTH])
  REPLACE_MBSTATE_T=0;  AC_SUBST([REPLACE_MBSTATE_T])
diff --git a/gl/m4/wcrtomb.m4 b/gl/m4/wcrtomb.m4
index 91530176..a69f17c4 100644
--- a/gl/m4/wcrtomb.m4
+++ b/gl/m4/wcrtomb.m4
@@ -1,6 +1,6 @@
 # wcrtomb.m4
-# serial 21
+# serial 22
-dnl Copyright (C) 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2008-2026 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.
@@ -33,7 +33,7 @@ AC_DEFUN([gl_FUNC_WCRTOMB],
    dnl fi
    if test $REPLACE_WCRTOMB = 0; then
      dnl On Android 4.3, wcrtomb produces wrong characters in the C locale.
-      dnl On AIX 4.3, OSF/1 5.1 and Solaris <= 11.3, wcrtomb (NULL, 0, NULL)
+      dnl On AIX 4.3 and Solaris <= 11.3, wcrtomb (NULL, 0, NULL)
      dnl sometimes returns 0 instead of 1.
      AC_REQUIRE([AC_PROG_CC])
      AC_REQUIRE([gt_LOCALE_FR])
@@ -83,8 +83,8 @@ int main ()
          dnl is present.
 changequote(,)dnl
          case "$host_os" in
-            # Guess no on AIX 4, OSF/1, Solaris, native Windows.
+            # Guess no on AIX 4, Solaris, native Windows.
-            aix4* | osf* | solaris* | mingw* | windows*)
+            aix4* | solaris* | mingw* | windows*)
              gl_cv_func_wcrtomb_retval="guessing no" ;;
            # Guess yes otherwise.
            *)
diff --git a/gl/m4/wctype.m4 b/gl/m4/wctype.m4
index 56593cd5..6a6cb3a4 100644
--- a/gl/m4/wctype.m4
+++ b/gl/m4/wctype.m4
@@ -1,6 +1,6 @@
 # wctype.m4
 # serial 6
-dnl Copyright (C) 2011-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2011-2026 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.
diff --git a/gl/m4/wctype_h.m4 b/gl/m4/wctype_h.m4
index 8e54678d..12b4c618 100644
--- a/gl/m4/wctype_h.m4
+++ b/gl/m4/wctype_h.m4
@@ -3,7 +3,7 @@
 dnl A placeholder for ISO C99 <wctype.h>, for platforms that lack it.
-dnl Copyright (C) 2006-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2006-2026 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.
diff --git a/gl/m4/wcwidth.m4 b/gl/m4/wcwidth.m4
index 2cc6ebb1..515076ba 100644
--- a/gl/m4/wcwidth.m4
+++ b/gl/m4/wcwidth.m4
@@ -1,6 +1,6 @@
 # wcwidth.m4
-# serial 38
+# serial 39
-dnl Copyright (C) 2006-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2006-2026 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.
@@ -44,7 +44,7 @@ AC_DEFUN([gl_FUNC_WCWIDTH],
    dnl On Mac OS X 10.3, wcwidth(0x0301) (COMBINING ACUTE ACCENT) returns 1.
    dnl On macOS 12.5, NetBSD 9.3, OpenBSD 5.0, MidnightBSD 1.1,
    dnl wcwidth(0x05B0) (HEBREW POINT SHEVA) returns 1.
-    dnl On macOS 12.5, NetBSD 9.3, MidnightBSD 1.1, OSF/1 5.1,
+    dnl On macOS 12.5, NetBSD 9.3, MidnightBSD 1.1,
    dnl wcwidth(0x200B) (ZERO WIDTH SPACE) returns 1.
    dnl On OpenBSD 5.8, wcwidth(0xFF1A) (FULLWIDTH COLON) returns 0.
    dnl This leads to bugs in 'ls' (coreutils).
diff --git a/gl/m4/wint_t.m4 b/gl/m4/wint_t.m4
index 8a3c7944..384462d2 100644
--- a/gl/m4/wint_t.m4
+++ b/gl/m4/wint_t.m4
@@ -1,6 +1,6 @@
 # wint_t.m4
 # serial 11
-dnl Copyright (C) 2003, 2007-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2003, 2007-2026 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.
diff --git a/gl/m4/xalloc.m4 b/gl/m4/xalloc.m4
index c10c4189..a0d0f060 100644
--- a/gl/m4/xalloc.m4
+++ b/gl/m4/xalloc.m4
@@ -1,6 +1,6 @@
 # xalloc.m4
 # serial 18
-dnl Copyright (C) 2002-2006, 2009-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2002-2006, 2009-2026 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.
diff --git a/gl/m4/xsize.m4 b/gl/m4/xsize.m4
index 157d635c..4e35a5fe 100644
--- a/gl/m4/xsize.m4
+++ b/gl/m4/xsize.m4
@@ -1,6 +1,6 @@
 # xsize.m4
 # serial 5
-dnl Copyright (C) 2003-2004, 2008-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2003-2004, 2008-2026 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.
diff --git a/gl/m4/zzgnulib.m4 b/gl/m4/zzgnulib.m4
index 343bda5c..fed091ca 100644
--- a/gl/m4/zzgnulib.m4
+++ b/gl/m4/zzgnulib.m4
@@ -1,6 +1,6 @@
 # zzgnulib.m4
 # serial 1
-dnl Copyright (C) 2020-2025 Free Software Foundation, Inc.
+dnl Copyright (C) 2020-2026 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.