$NetBSD: patch-ad,v 1.2 2015/03/15 15:07:47 mef Exp $

--- common.h.orig	2012-06-07 14:45:48.000000000 +0900
+++ common.h	2015-03-12 11:27:47.000000000 +0900
@@ -253,7 +253,7 @@ struct host_map {
 struct domain {
 	char			*name;		/* domain part of mail addr */
 	int			stat;		/* error status for MX query */
-	char			*response;	/* error response */
+	const char			*response;	/* error response */
 	struct mx		*firstmx;	/* first MX */
 	struct mx		*curmx;		/* working MX */
 	int			checked;	/* temporary local flag */
@@ -284,7 +284,7 @@ struct recipient {
 	int			stat;		/* current status */
 	int			result;		/* final result */
 	int			again;		/* try the same MX again */
-	char			*response;	/* final response */
+	const char			*response;	/* final response */
 	struct domain		*domain;	/* domain part */
 	struct host		*final;
 	struct recipient	*next;		/* next recipient */
@@ -427,3 +427,9 @@ union SockAddrUnion {
 #endif
 };
 typedef union SockAddrUnion SockAddr;
+
+#ifdef __STDC__
+#define P(c)	c
+#else
+#define P(c)
+#endif