1 files changed, 9 insertions, 16 deletions

diff --git a/gl/m4/getopt.m4 b/gl/m4/getopt.m4
index 297722ea..c620b2b7 100644
--- a/gl/m4/getopt.m4
+++ b/gl/m4/getopt.m4
@@ -1,9 +1,10 @@
 # getopt.m4
-# serial 49
-dnl Copyright (C) 2002-2006, 2008-2024 Free Software Foundation, Inc.
+# serial 52
+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.
+dnl This file is offered as-is, without any warranty.
 
 # Request a POSIX compliant getopt function.
 AC_DEFUN([gl_FUNC_GETOPT_POSIX],
@@ -77,7 +78,7 @@ AC_DEFUN([gl_GETOPT_CHECK_HEADERS],
   fi
 
   dnl POSIX 2008 does not specify leading '+' behavior, but see
-  dnl http://austingroupbugs.net/view.php?id=191 for a recommendation on
+  dnl https://austingroupbugs.net/view.php?id=191 for a recommendation on
   dnl the next version of POSIX.  For now, we only guarantee leading '+'
   dnl behavior with getopt-gnu.
   if test -z "$gl_replace_getopt"; then
@@ -87,8 +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 Solaris 9, musl libc), there is no such mechanism.
+        dnl setting 'optind' to 0; on others again (HP-UX, Solaris 9,
+        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).
@@ -237,8 +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,
-                OSF/1 5.1, Solaris 10.  */
+                and fails on Mac OS X 10.5, AIX 5.2, HP-UX 11, Solaris 10.  */
              {
                static char conftest[] = "conftest";
                static char plus[] = "-+";
@@ -249,7 +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";
@@ -366,14 +366,7 @@ dnl is ambiguous with environment values that contain newlines.
 
 AC_DEFUN([gl_GETOPT_SUBSTITUTE_HEADER],
 [
-  AC_CHECK_HEADERS_ONCE([sys/cdefs.h])
-  if test $ac_cv_header_sys_cdefs_h = yes; then
-    HAVE_SYS_CDEFS_H=1
-  else
-    HAVE_SYS_CDEFS_H=0
-  fi
-  AC_SUBST([HAVE_SYS_CDEFS_H])
-
+  gl_CHECK_HEADER_SYS_CDEFS_H
   AC_DEFINE([__GETOPT_PREFIX], [[rpl_]],
     [Define to rpl_ if the getopt replacement functions and variables
      should be used.])