Update from Gnulib by running admin/merge-gnulib

lib/fcntl.in.h

@@ -369,8 +369,12 @@ _GL_WARN_ON_USE (openat, "openat is not portable - "
 # define O_RSYNC 0
 #endif
 
+#if defined O_SEARCH && defined O_PATH && O_SEARCH == O_PATH
+# undef O_SEARCH /* musl mistakenly #defines O_SEARCH to O_PATH.  */
+#endif
+
 #ifndef O_SEARCH
-# define O_SEARCH O_RDONLY /* This is often close enough in older systems.  */
+# define O_SEARCH O_RDONLY /* Often close enough in non-POSIX systems.  */
 #endif
 
 #ifndef O_SYNC

lib/file-has-acl.c

@@ -99,6 +99,36 @@ enum {
   ACE4_IDENTIFIER_GROUP        = 0x00000040
 };
 
+/* AI indicates XATTR may be present but wasn't accessible.
+   This is the case when [l]listxattr failed with E2BIG,
+   or failed with EACCES which in Linux kernel 6.12 NFS can mean merely
+   that we lack read access.
+*/
+
+static bool
+aclinfo_may_indicate_xattr (struct aclinfo const *ai)
+{
+  return ai->size < 0 && (ai->u.err == EACCES || ai->u.err == E2BIG);
+}
+
+/* Does NAME have XATTR?  */
+
+static bool
+has_xattr (char const *xattr, struct aclinfo const *ai,
+           MAYBE_UNUSED char const *restrict name, MAYBE_UNUSED int flags)
+{
+  if (ai && aclinfo_has_xattr (ai, xattr))
+    return true;
+  else if (!ai || aclinfo_may_indicate_xattr (ai))
+    {
+      int ret = ((flags & ACL_SYMLINK_FOLLOW ? getxattr : lgetxattr)
+                (name, xattr, NULL, 0));
+      if (0 <= ret || (errno == ERANGE || errno == E2BIG))
+        return true;
+    }
+  return false;
+}
+
 /* Does AI's xattr set contain XATTR?  */
 
 bool
@@ -176,11 +206,13 @@ get_aclinfo (char const *name, struct aclinfo *ai, int flags)
         }
     }
 
-  if (0 < ai->size && flags & ACL_GET_SCONTEXT)
+  /* A security context can exist only if extended attributes do.  */
+  if (flags & ACL_GET_SCONTEXT
+      && (0 < ai->size || aclinfo_may_indicate_xattr (ai)))
     {
       if (is_smack_enabled ())
         {
-          if (aclinfo_has_xattr (ai, XATTR_NAME_SMACK))
+          if (ai->size < 0 || aclinfo_has_xattr (ai, XATTR_NAME_SMACK))
             {
               ssize_t r = smack_new_label_from_path (name, "security.SMACK64",
                                                      flags & ACL_SYMLINK_FOLLOW,
@@ -191,7 +223,7 @@ get_aclinfo (char const *name, struct aclinfo *ai, int flags)
       else
         {
 # if USE_SELINUX_SELINUX_H
-          if (aclinfo_has_xattr (ai, XATTR_NAME_SELINUX))
+          if (ai->size < 0 || aclinfo_has_xattr (ai, XATTR_NAME_SELINUX))
             {
               ssize_t r =
                 ((flags & ACL_SYMLINK_FOLLOW ? getfilecon : lgetfilecon)
@@ -352,7 +384,7 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name,
   int initial_errno = errno;
   get_aclinfo (name, ai, flags);
 
-  if (ai->size <= 0)
+  if (!aclinfo_may_indicate_xattr (ai) && ai->size <= 0)
     {
       errno = ai->size < 0 ? ai->u.err : initial_errno;
       return ai->size;
@@ -363,11 +395,11 @@ file_has_aclinfo (MAYBE_UNUSED char const *restrict name,
      In earlier Fedora the two types of ACLs were mutually exclusive.
      Attempt to work correctly on both kinds of systems.  */
 
-  if (!aclinfo_has_xattr (ai, XATTR_NAME_NFSV4_ACL))
+  if (!has_xattr (XATTR_NAME_NFSV4_ACL, ai, name, flags))
     return
-      (aclinfo_has_xattr (ai, XATTR_NAME_POSIX_ACL_ACCESS)
+      (has_xattr (XATTR_NAME_POSIX_ACL_ACCESS, ai, name, flags)
        || ((d_type == DT_DIR || d_type == DT_UNKNOWN)
-           && aclinfo_has_xattr (ai, XATTR_NAME_POSIX_ACL_DEFAULT)));
+           && has_xattr (XATTR_NAME_POSIX_ACL_DEFAULT, ai, name, flags)));
 
   /* A buffer large enough to hold any trivial NFSv4 ACL.
      The max length of a trivial NFSv4 ACL is 6 words for owner,

lib/gnulib.mk.in

@@ -489,6 +489,8 @@ GL_GNULIB_MBSSPN = @GL_GNULIB_MBSSPN@
 GL_GNULIB_MBSSTR = @GL_GNULIB_MBSSTR@
 GL_GNULIB_MBSTOK_R = @GL_GNULIB_MBSTOK_R@
 GL_GNULIB_MBSTOWCS = @GL_GNULIB_MBSTOWCS@
+GL_GNULIB_MBS_ENDSWITH = @GL_GNULIB_MBS_ENDSWITH@
+GL_GNULIB_MBS_STARTSWITH = @GL_GNULIB_MBS_STARTSWITH@
 GL_GNULIB_MBTOWC = @GL_GNULIB_MBTOWC@
 GL_GNULIB_MDA_ACCESS = @GL_GNULIB_MDA_ACCESS@
 GL_GNULIB_MDA_CHDIR = @GL_GNULIB_MDA_CHDIR@
@@ -642,6 +644,8 @@ GL_GNULIB_STRTOUL = @GL_GNULIB_STRTOUL@
 GL_GNULIB_STRTOULL = @GL_GNULIB_STRTOULL@
 GL_GNULIB_STRTOUMAX = @GL_GNULIB_STRTOUMAX@
 GL_GNULIB_STRVERSCMP = @GL_GNULIB_STRVERSCMP@
+GL_GNULIB_STR_ENDSWITH = @GL_GNULIB_STR_ENDSWITH@
+GL_GNULIB_STR_STARTSWITH = @GL_GNULIB_STR_STARTSWITH@
 GL_GNULIB_SYMLINK = @GL_GNULIB_SYMLINK@
 GL_GNULIB_SYMLINKAT = @GL_GNULIB_SYMLINKAT@
 GL_GNULIB_SYSTEM_POSIX = @GL_GNULIB_SYSTEM_POSIX@
@@ -3655,6 +3659,8 @@ string.h: string.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H
 	      -e 's/@''GNULIB_MBSSPN''@/$(GL_GNULIB_MBSSPN)/g' \
 	      -e 's/@''GNULIB_MBSSEP''@/$(GL_GNULIB_MBSSEP)/g' \
 	      -e 's/@''GNULIB_MBSTOK_R''@/$(GL_GNULIB_MBSTOK_R)/g' \
+	      -e 's/@''GNULIB_MBS_ENDSWITH''@/$(GL_GNULIB_MBS_ENDSWITH)/g' \
+	      -e 's/@''GNULIB_MBS_STARTSWITH''@/$(GL_GNULIB_MBS_STARTSWITH)/g' \
 	      -e 's/@''GNULIB_MEMCHR''@/$(GL_GNULIB_MEMCHR)/g' \
 	      -e 's/@''GNULIB_MEMMEM''@/$(GL_GNULIB_MEMMEM)/g' \
 	      -e 's/@''GNULIB_MEMPCPY''@/$(GL_GNULIB_MEMPCPY)/g' \
@@ -3673,6 +3679,8 @@ string.h: string.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H
 	      -e 's/@''GNULIB_STRSTR''@/$(GL_GNULIB_STRSTR)/g' \
 	      -e 's/@''GNULIB_STRCASESTR''@/$(GL_GNULIB_STRCASESTR)/g' \
 	      -e 's/@''GNULIB_STRTOK_R''@/$(GL_GNULIB_STRTOK_R)/g' \
+	      -e 's/@''GNULIB_STR_ENDSWITH''@/$(GL_GNULIB_STR_ENDSWITH)/g' \
+	      -e 's/@''GNULIB_STR_STARTSWITH''@/$(GL_GNULIB_STR_STARTSWITH)/g' \
 	      -e 's/@''GNULIB_STRERROR''@/$(GL_GNULIB_STRERROR)/g' \
 	      -e 's/@''GNULIB_STRERROR_R''@/$(GL_GNULIB_STRERROR_R)/g' \
 	      -e 's/@''GNULIB_STRERRORNAME_NP''@/$(GL_GNULIB_STRERRORNAME_NP)/g' \

lib/mktime-internal.h

@@ -19,6 +19,9 @@
 
 #ifndef _LIBC
 # include <time.h>
+# define __libc_lock_lock(lock) ((void) 0)
+# define __libc_lock_unlock(lock) ((void) 0)
+# define __tzset_unlocked() tzset ()
 #endif
 
 /* mktime_offset_t is a signed type wide enough to hold a UTC offset
@@ -73,6 +76,8 @@ typedef int mktime_offset_t;
 /* Subroutine of mktime.  Return the time_t representation of TP and
    normalize TP, given that a struct tm * maps to a time_t.  If
    LOCAL, the mapping is performed by localtime_r, otherwise by gmtime_r.
-   Record next guess for localtime-gmtime offset in *OFFSET.  */
+   Record next guess for localtime-gmtime offset in *OFFSET.
+
+   If _LIBC, the caller must lock __tzset_lock.  */
 extern __time64_t __mktime_internal (struct tm *tp, bool local,
                                      mktime_offset_t *offset) attribute_hidden;

lib/mktime.c

@@ -62,6 +62,9 @@
 # define NEED_MKTIME_WORKING 0
 #endif
 
+#ifdef _LIBC
+# include <tzset.h>
+#endif
 #include "mktime-internal.h"
 
 #if !defined _LIBC && (NEED_MKTIME_WORKING || NEED_MKTIME_WINDOWS)
@@ -98,8 +101,8 @@ my_tzset (void)
   tzset ();
 # endif
 }
-# undef __tzset
+# undef tzset
-# define __tzset() my_tzset ()
+# define tzset() my_tzset ()
 #endif
 
 #if defined _LIBC || NEED_MKTIME_WORKING || NEED_MKTIME_INTERNAL
@@ -250,6 +253,7 @@ tm_diff (long_int year, long_int yday, int hour, int min, int sec,
 		     tp->tm_hour, tp->tm_min, tp->tm_sec);
 }
 
+#ifndef _LIBC
 /* Convert T to a struct tm value in *TM.  Use localtime64_r if LOCAL,
    otherwise gmtime64_r.  T must be in range for __time64_t.  Return
    TM if successful, NULL (setting errno) on failure.  */
@@ -262,8 +266,8 @@ convert_time (long_int t, bool local, struct tm *tm)
   else
     return __gmtime64_r (&x, tm);
 }
-/* Call it __tzconvert to sync with other parts of glibc.  */
+# define __tz_convert convert_time
-#define __tz_convert convert_time
+#endif
 
 /* Convert *T to a broken down time in *TP (as if by localtime if
    LOCAL, otherwise as if by gmtime).  If *T is out of range for
@@ -320,7 +324,9 @@ ranged_convert (bool local, long_int *t, struct tm *tp)
    If *OFFSET's guess is correct, only one reverse mapping call is
    needed.  If successful, set *TP to the canonicalized struct tm;
    otherwise leave *TP alone, return ((time_t) -1) and set errno.
-   This function is external because it is used also by timegm.c.  */
+   This function is external because it is used also by timegm.c.
+
+   If _LIBC, the caller must lock __tzset_lock.  */
 __time64_t
 __mktime_internal (struct tm *tp, bool local, mktime_offset_t *offset)
 {
@@ -349,12 +355,10 @@ __mktime_internal (struct tm *tp, bool local, mktime_offset_t *offset)
   int mday = tp->tm_mday;
   int mon = tp->tm_mon;
   int year_requested = tp->tm_year;
+  int isdst = tp->tm_isdst;
 
-  /* Ignore any tm_isdst request for timegm.  */
+  /* True if the previous probe was DST.  */
-  int isdst = local ? tp->tm_isdst : 0;
+  bool dst2 = false;
-
-  /* 1 if the previous probe was DST.  */
-  int dst2 = 0;
 
   /* Ensure that mon is in range, and set year accordingly.  */
   int mon_remainder = mon % 12;
@@ -443,13 +447,10 @@ __mktime_internal (struct tm *tp, bool local, mktime_offset_t *offset)
 
 	 Heuristic: probe the adjacent timestamps in both directions,
 	 looking for the desired isdst.  If none is found within a
-	 reasonable duration bound, assume a one-hour DST difference.
+	 reasonable duration bound, ignore the disagreement.
 	 This should work for all real time zone histories in the tz
 	 database.  */
 
-      /* +1 if we wanted standard time but got DST, -1 if the reverse.  */
-      int dst_difference = (isdst == 0) - (tm.tm_isdst == 0);
-
       /* Distance between probes when looking for a DST boundary.  In
 	 tzdata2003a, the shortest period of DST is 601200 seconds
 	 (e.g., America/Recife starting 2000-10-08 01:00), and the
@@ -459,21 +460,17 @@ __mktime_internal (struct tm *tp, bool local, mktime_offset_t *offset)
 	 periods when probing.  */
       int stride = 601200;
 
-      /* In TZDB 2021e, the longest period of DST (or of non-DST), in
+      /* Do not probe too far away from the requested time,
-	 which the DST (or adjacent DST) difference is not one hour,
+         by striding until at least a year has passed, but then giving up.
-	 is 457243209 seconds: e.g., America/Cambridge_Bay with leap
+         This helps avoid unexpected results in (for example) Asia/Kolkata,
-	 seconds, starting 1965-10-31 00:00 in a switch from
+         for which today's users expect to see no DST even though it
-	 double-daylight time (-05) to standard time (-07), and
+         did observe DST long ago.  */
-	 continuing to 1980-04-27 02:00 in a switch from standard time
+      int year_seconds_bound = 366 * 24 * 60 * 60 + 1;
-	 (-07) to daylight time (-06).  */
+      int delta_bound = year_seconds_bound + stride;
-      int duration_max = 457243209;
-
-      /* Search in both directions, so the maximum distance is half
-	 the duration; add the stride to avoid off-by-1 problems.  */
-      int delta_bound = duration_max / 2 + stride;
 
       int delta, direction;
 
+      /* Search in both directions, closest first.  */
       for (delta = stride; delta < delta_bound; delta += stride)
 	for (direction = -1; direction <= 1; direction += 2)
 	  {
@@ -503,13 +500,8 @@ __mktime_internal (struct tm *tp, bool local, mktime_offset_t *offset)
 	      }
 	  }
 
-      /* No unusual DST offset was found nearby.  Assume one-hour DST.  */
+      /* No probe with the requested tm_isdst was found nearby.
-      t += 60 * 60 * dst_difference;
+         Ignore the requested tm_isdst.  */
-      if (mktime_min <= t && t <= mktime_max && __tz_convert (t, local, &tm))
-	goto offset_found;
-
-      __set_errno (EOVERFLOW);
-      return -1;
     }
 
  offset_found:
@@ -548,17 +540,19 @@ __mktime_internal (struct tm *tp, bool local, mktime_offset_t *offset)
 __time64_t
 __mktime64 (struct tm *tp)
 {
-  /* POSIX.1 requires mktime to set external variables like 'tzname'
+  __libc_lock_lock (__tzset_lock);
-     as though tzset had been called.  */
+  __tzset_unlocked ();
-  __tzset ();
 
 # if defined _LIBC || NEED_MKTIME_WORKING
   static mktime_offset_t localtime_offset;
-  return __mktime_internal (tp, true, &localtime_offset);
+  __time64_t result = __mktime_internal (tp, true, &localtime_offset);
 # else
 #  undef mktime
-  return mktime (tp);
+  __time64_t result = mktime (tp);
 # endif
+
+  __libc_lock_unlock (__tzset_lock);
+  return result;
 }
 #endif /* _LIBC || NEED_MKTIME_WORKING || NEED_MKTIME_WINDOWS */
 

lib/stdlib.in.h

@@ -62,8 +62,9 @@
 /* NetBSD 5.0 mis-defines NULL.  */
 #include <stddef.h>
 
-/* MirBSD 10 defines WEXITSTATUS in <sys/wait.h>, not in <stdlib.h>.  */
+/* MirBSD 10 defines WEXITSTATUS in <sys/wait.h>, not in <stdlib.h>.
-#if @GNULIB_SYSTEM_POSIX@ && !defined WEXITSTATUS
+   glibc 2.40 defines WCOREDUMP in <sys/wait.h>, not in <stdlib.h>.  */
+#if @GNULIB_SYSTEM_POSIX@ && !(defined WEXITSTATUS && defined WCOREDUMP)
 # include <sys/wait.h>
 #endif
 

lib/string.in.h

@@ -1077,6 +1077,22 @@ _GL_WARN_ON_USE (strtok_r, "strtok_r is unportable - "
 /* The following functions are not specified by POSIX.  They are gnulib
    extensions.  */
 
+#if @GNULIB_STR_STARTSWITH@
+/* Returns true if STRING starts with PREFIX.
+   Returns false otherwise.  */
+_GL_EXTERN_C bool str_startswith (const char *string, const char *prefix)
+     _GL_ATTRIBUTE_PURE
+     _GL_ARG_NONNULL ((1, 2));
+#endif
+
+#if @GNULIB_STR_ENDSWITH@
+/* Returns true if STRING ends with SUFFIX.
+   Returns false otherwise.  */
+_GL_EXTERN_C bool str_endswith (const char *string, const char *prefix)
+     _GL_ATTRIBUTE_PURE
+     _GL_ARG_NONNULL ((1, 2));
+#endif
+
 #if @GNULIB_MBSLEN@
 /* Return the number of multibyte characters in the character string STRING.
    This considers multibyte characters, unlike strlen, which counts bytes.  */
@@ -1301,6 +1317,26 @@ _GL_EXTERN_C char * mbstok_r (char *restrict string, const char *delim,
      _GL_ARG_NONNULL ((2, 3));
 #endif
 
+#if @GNULIB_MBS_STARTSWITH@
+/* Returns true if STRING starts with PREFIX.
+   Returns false otherwise.  */
+_GL_EXTERN_C bool mbs_startswith (const char *string, const char *prefix)
+     _GL_ATTRIBUTE_PURE
+     _GL_ARG_NONNULL ((1, 2));
+/* No extra code is needed for multibyte locales for this function.  */
+# define mbs_startswith str_startswith
+#endif
+
+#if @GNULIB_MBS_ENDSWITH@
+/* Returns true if STRING ends with SUFFIX.
+   Returns false otherwise.
+   Unlike str_endswith(), this function works correctly in multibyte locales.
+ */
+_GL_EXTERN_C bool mbs_endswith (const char *string, const char *suffix)
+     _GL_ATTRIBUTE_PURE
+     _GL_ARG_NONNULL ((1, 2));
+#endif
+
 /* Map any int, typically from errno, into an error message.  */
 #if @GNULIB_STRERROR@
 # if @REPLACE_STRERROR@

lib/sys_select.in.h

@@ -165,12 +165,18 @@
 
 #if @HAVE_WINSOCK2_H@
 
+/* Define type 'suseconds_t'.  */
+# if !GNULIB_defined_suseconds_t
+typedef int suseconds_t;
+#  define GNULIB_defined_suseconds_t 1
+# endif
+
 # if !GNULIB_defined_rpl_fd_isset
 
 /* Re-define FD_ISSET to avoid a WSA call while we are not using
    network sockets.  */
 static int
-rpl_fd_isset (SOCKET fd, fd_set * set)
+rpl_fd_isset (SOCKET fd, const fd_set * set)
 {
   u_int i;
   if (set == NULL)

m4/assert_h.m4

@@ -1,5 +1,5 @@
 # assert_h.m4
-# serial 4
+# serial 5
 dnl Copyright (C) 2011-2025 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -64,11 +64,13 @@ AC_DEFUN([gl_ASSERT_H],
 [#if (!(defined __clang__ \
        ? (defined __cplusplus \
           ? __cplusplus >= 201703L \
-          : __STDC_VERSION__ >= 202000L && __clang_major__ >= 16) \
+          : __STDC_VERSION__ >= 202000L && __clang_major__ >= 16 \
+            && !defined __sun) \
        : (defined __GNUC__ \
           ? (defined __cplusplus \
              ? __cplusplus >= 201103L && __GNUG__ >= 6 \
-             : __STDC_VERSION__ >= 202000L && __GNUC__ >= 13) \
+             : __STDC_VERSION__ >= 202000L && __GNUC__ >= 13 \
+               && !defined __sun) \
           : defined HAVE_C_STATIC_ASSERT)) \
      && !defined assert \
      && (!defined __cplusplus \

m4/string_h.m4

@@ -1,5 +1,5 @@
 # string_h.m4
-# serial 39
+# serial 43
 dnl Copyright (C) 2007-2025 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -70,6 +70,8 @@ AC_DEFUN([gl_STRING_H_REQUIRE_DEFAULTS],
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_STRSTR])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_STRCASESTR])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_STRTOK_R])
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_STR_STARTSWITH])
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_STR_ENDSWITH])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_MBSLEN])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_MBSNLEN])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_MBSCHR])
@@ -84,6 +86,8 @@ AC_DEFUN([gl_STRING_H_REQUIRE_DEFAULTS],
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_MBSSPN])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_MBSSEP])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_MBSTOK_R])
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_MBS_STARTSWITH])
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_MBS_ENDSWITH])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_STRERROR])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_STRERROR_R])
     gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_STRERRORNAME_NP])

m4/sys_socket_h.m4

@@ -1,5 +1,5 @@
 # sys_socket_h.m4
-# serial 29
+# serial 31
 dnl Copyright (C) 2005-2025 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -53,24 +53,10 @@ AC_DEFUN_ONCE([gl_SYS_SOCKET_H],
   fi
   # We need to check for ws2tcpip.h now.
   gl_PREREQ_SYS_H_SOCKET
-  AC_CHECK_TYPES([struct sockaddr_storage, sa_family_t],,,[
+  gl_PREREQ_SYS_SA_FAMILY
-  /* sys/types.h is not needed according to POSIX, but the
-     sys/socket.h in i386-unknown-freebsd4.10 and
-     powerpc-apple-darwin5.5 required it. */
-#include <sys/types.h>
-#ifdef HAVE_SYS_SOCKET_H
-#include <sys/socket.h>
-#endif
-#ifdef HAVE_WS2TCPIP_H
-#include <ws2tcpip.h>
-#endif
-])
   if test $ac_cv_type_struct_sockaddr_storage = no; then
     HAVE_STRUCT_SOCKADDR_STORAGE=0
   fi
-  if test $ac_cv_type_sa_family_t = no; then
-    HAVE_SA_FAMILY_T=0
-  fi
   if test $ac_cv_type_struct_sockaddr_storage != no; then
     AC_CHECK_MEMBERS([struct sockaddr_storage.ss_family],
       [],
@@ -159,6 +145,32 @@ AC_DEFUN([gl_PREREQ_SYS_H_WS2TCPIP],
   AC_SUBST([HAVE_WS2TCPIP_H])
 ])
 
+# Common prerequisites of the <sys/socket.h> replacement and of the <sys/un.h>
+# replacement.
+# Sets and substitutes HAVE_SA_FAMILY_T.
+AC_DEFUN([gl_PREREQ_SYS_SA_FAMILY],
+[
+  AC_REQUIRE([gl_CHECK_SOCKET_HEADERS])
+  AC_CHECK_TYPES([struct sockaddr_storage, sa_family_t],,,[
+  /* sys/types.h is not needed according to POSIX, but the
+     sys/socket.h in i386-unknown-freebsd4.10 and
+     powerpc-apple-darwin5.5 required it. */
+#include <sys/types.h>
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+#ifdef HAVE_WS2TCPIP_H
+#include <ws2tcpip.h>
+#endif
+])
+  if test $ac_cv_type_sa_family_t = yes; then
+    HAVE_SA_FAMILY_T=1
+  else
+    HAVE_SA_FAMILY_T=0
+  fi
+  AC_SUBST([HAVE_SA_FAMILY_T])
+])
+
 # gl_SYS_SOCKET_MODULE_INDICATOR([modulename])
 # sets the shell variable that indicates the presence of the given module
 # to a C preprocessor expression that will evaluate to 1.
@@ -203,6 +215,5 @@ AC_DEFUN([gl_SYS_SOCKET_H_DEFAULTS],
   HAVE_STRUCT_SOCKADDR_STORAGE=1; AC_SUBST([HAVE_STRUCT_SOCKADDR_STORAGE])
   HAVE_STRUCT_SOCKADDR_STORAGE_SS_FAMILY=1;
                         AC_SUBST([HAVE_STRUCT_SOCKADDR_STORAGE_SS_FAMILY])
-  HAVE_SA_FAMILY_T=1;   AC_SUBST([HAVE_SA_FAMILY_T])
   HAVE_ACCEPT4=1;       AC_SUBST([HAVE_ACCEPT4])
 ])