$NetBSD: patch-ah,v 1.1 2002/10/14 11:49:56 skrll Exp $

--- aclocal.m4.orig	Sun Jan 27 11:03:40 2002
+++ aclocal.m4
@@ -1254,6 +1254,48 @@ AC_DEFINE_UNQUOTED($1, $nsig)
 ])
 
 dnl ##
+dnl ##  Check for FD_SETSIZE
+dnl ##
+dnl ##  configure.in:
+dnl ##    AC_FDSETSIZE(<varname>)
+
+AC_DEFUN(AC_FDSETSIZE,[dnl
+AC_MSG_CHECKING(for value of FD_SETSIZE)
+cross_compile=no
+AC_TRY_RUN(
+changequote(<<, >>)dnl
+<<
+#include <stdio.h>
+#include <sys/types.h>
+
+int main(int argc, char *argv[])
+{
+    FILE *fp;
+    int ac_fdsetsize;
+
+#if defined(FD_SETSIZE)
+    ac_fdsetsize = FD_SETSIZE;
+#else
+    ac_fdsetsize = (sizeof(fd_set)*8);
+#endif
+    if ((fp = fopen("conftestval", "w")) == NULL)
+        exit(1);
+    fprintf(fp, "%d\n", ac_fdsetsize);
+    fclose(fp);
+    exit(0);
+}
+>>
+changequote([, ])dnl
+,
+ac_fdsetsize=`cat conftestval`,
+ac_fdsetsize=1024,
+ac_fdsetsize=1024
+)dnl
+AC_MSG_RESULT([$ac_fdsetsize])
+$1="$ac_fdsetsize"
+])
+
+dnl ##
 dnl ##  Check for an external/extension library.
 dnl ##  - is aware of <libname>-config style scripts
 dnl ##  - searches under standard paths include, lib, etc.