1 files changed, 13 insertions, 4 deletions

diff --git a/src/lib/libc/net/res_mkquery.c b/src/lib/libc/net/res_mkquery.c
index 61595a6e8c..e414b5060d 100644
--- a/src/lib/libc/net/res_mkquery.c
+++ b/src/lib/libc/net/res_mkquery.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: res_mkquery.c,v 1.9 2001/06/11 10:06:00 itojun Exp $  */
+/*      $OpenBSD: res_mkquery.c,v 1.10 2001/07/31 22:02:18 jakob Exp $  */
 
 /*
  * ++Copyright++ 1985, 1993
@@ -60,7 +60,7 @@
 static char sccsid[] = "@(#)res_mkquery.c       8.1 (Berkeley) 6/4/93";
 static char rcsid[] = "$From: res_mkquery.c,v 8.5 1996/08/27 08:33:28 vixie Exp $";
 #else
-static char rcsid[] = "$OpenBSD: res_mkquery.c,v 1.9 2001/06/11 10:06:00 itojun Exp $";
+static char rcsid[] = "$OpenBSD: res_mkquery.c,v 1.10 2001/07/31 22:02:18 jakob Exp $";
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -221,8 +221,17 @@ res_opt(n0, buf, buflen, anslen)
         cp += INT16SZ;
         *cp++ = NOERROR;        /* extended RCODE */
         *cp++ = 0;              /* EDNS version */
-        __putshort(0, cp);      /* MBZ */
-        cp += INT16SZ;
+        if (_res.options & RES_USE_DNSSEC) {
+#ifdef DEBUG
+                if (_res.options & RES_DEBUG)
+                        printf(";; res_opt()... ENDS0 DNSSEC OK\n");
+#endif /* DEBUG */
+                __putshort(DNS_MESSAGEEXTFLAG_DO, cp);  /* EDNS Z field */
+                cp += INT16SZ;
+        } else {
+                __putshort(0, cp);      /* EDNS Z field */
+                cp += INT16SZ;
+        }
         __putshort(0, cp);      /* RDLEN */
         cp += INT16SZ;
         hp->arcount = htons(ntohs(hp->arcount) + 1);