$NetBSD: patch-ai,v 1.6 2015/09/01 13:34:47 kim Exp $

This glues in the code from patch-am (see also path-al and patch-an).

--- os.h.orig	2015-06-28 21:22:56.000000000 +0000
+++ os.h	2015-09-01 12:37:29.000000000 +0000
@@ -71,9 +71,6 @@
 # undef exit
 #endif /* sun */
 
-#ifndef linux /* all done in <errno.h> */
-extern int errno;
-#endif /* linux */
 #ifndef HAVE_STRERROR
 /* No macros, please */
 #undef strerror
@@ -250,10 +247,17 @@
 #endif
 
 #if defined(UTMPOK) || defined(BUGGYGETLOGIN)
-# if defined(SVR4) && !defined(DGUX) && !defined(__hpux)
+# if (defined(SVR4) && !defined(DGUX) && !defined(__hpux)) \
+  || (defined(__NetBSD_Version__) && (__NetBSD_Version__ >= 106050000)) \
+  || (defined(__DragonFly__) && (__DragonFly_version >= 200902))
 #  include <utmpx.h>
-#  ifdef UTMPX_FILE /* GNU extension */
+#  if defined(UTMPX_FILE) /* GNU extension */
 #   define UTMPFILE	UTMPX_FILE
+#  elif defined(_PATH_UTMPX)
+#   define UTMPFILE	_PATH_UTMPX
+#  endif
+#  if defined(__NetBSD__)
+#   define NetBSD_UTMP
 #  endif
 #  define utmp		utmpx
 #  define getutent	getutxent