Define NULL to be __null for C++: better quality of implementation.

__null is a magic constant of integral type that converts to a null pointer
as should be, but warns for ambiguity when used to resolved an overload
between an integral type and a pointer type.

src/include/dirent.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: dirent.h,v 1.4 1998/11/20 11:18:25 d Exp $	*/
+/*	$OpenBSD: dirent.h,v 1.5 1999/06/11 22:47:48 espie Exp $	*/
 /*	$NetBSD: dirent.h,v 1.9 1995/03/26 20:13:37 jtc Exp $	*/
 
 /*-
@@ -82,8 +82,12 @@ typedef struct _dirdesc {
 #define __DTF_READALL	0x0008	/* everything has been read */
 
 #ifndef NULL
+#ifdef 	__GNUG__
+#define NULL	__null
+#else
 #define	NULL	0
 #endif
+#endif
 
 #endif /* _POSIX_SOURCE */
 

src/include/locale.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: locale.h,v 1.2 1997/09/21 10:45:41 niklas Exp $	*/
+/*	$OpenBSD: locale.h,v 1.3 1999/06/11 22:47:48 espie Exp $	*/
 /*	$NetBSD: locale.h,v 1.6 1994/10/26 00:56:02 cgd Exp $	*/
 
 /*
@@ -61,8 +61,12 @@ struct lconv {
 };
 
 #ifndef NULL
+#ifdef 	__GNUG__
+#define NULL	__null
+#else
 #define	NULL	0
 #endif
+#endif
 
 #define	LC_ALL		0
 #define	LC_COLLATE	1

src/include/stddef.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: stddef.h,v 1.2 1997/09/21 10:45:52 niklas Exp $	*/
+/*	$OpenBSD: stddef.h,v 1.3 1999/06/11 22:47:48 espie Exp $	*/
 /*	$NetBSD: stddef.h,v 1.4 1994/10/26 00:56:26 cgd Exp $	*/
 
 /*-
@@ -54,8 +54,12 @@ typedef	_BSD_WCHAR_T_	wchar_t;
 #endif
 
 #ifndef	NULL
+#ifdef 	__GNUG__
+#define NULL	__null
+#else
 #define	NULL	0
 #endif
+#endif
 
 #define	offsetof(type, member)	((size_t)(&((type *)0)->member))
 

src/include/stdlib.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: stdlib.h,v 1.9 1999/02/25 21:40:15 millert Exp $	*/
+/*	$OpenBSD: stdlib.h,v 1.10 1999/06/11 22:47:48 espie Exp $	*/
 /*	$NetBSD: stdlib.h,v 1.25 1995/12/27 21:19:08 jtc Exp $	*/
 
 /*-
@@ -73,8 +73,12 @@ typedef struct {
 
 
 #ifndef	NULL
+#ifdef 	__GNUG__
+#define NULL	__null
+#else
 #define	NULL	0
 #endif
+#endif
 
 #define	EXIT_FAILURE	1
 #define	EXIT_SUCCESS	0

src/include/time.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: time.h,v 1.6 1999/05/14 23:18:54 aaron Exp $	*/
+/*	$OpenBSD: time.h,v 1.7 1999/06/11 22:47:48 espie Exp $	*/
 /*	$NetBSD: time.h,v 1.9 1994/10/26 00:56:35 cgd Exp $	*/
 
 /*
@@ -48,8 +48,12 @@
 #include <machine/ansi.h>
 
 #ifndef	NULL
+#ifdef 	__GNUG__
+#define NULL	__null
+#else
 #define	NULL	0
 #endif
+#endif
 
 #ifdef	_BSD_CLOCK_T_
 typedef	_BSD_CLOCK_T_	clock_t;

src/include/unistd.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: unistd.h,v 1.25 1999/05/22 23:49:48 weingart Exp $ */
+/*	$OpenBSD: unistd.h,v 1.26 1999/06/11 22:47:47 espie Exp $ */
 /*	$NetBSD: unistd.h,v 1.26.4.1 1996/05/28 02:31:51 mrg Exp $	*/
 
 /*-
@@ -48,8 +48,12 @@
 #define	STDERR_FILENO	2	/* standard error file descriptor */
 
 #ifndef NULL
+#ifdef 	__GNUG__
+#define NULL	__null
+#else
 #define	NULL		0	/* null pointer constant */
 #endif
+#endif
 
 __BEGIN_DECLS
 __dead void	 _exit __P((int)) __attribute__((noreturn));