From 6883a918f790147fd98e21b2c3d3d479320f3ed5 Mon Sep 17 00:00:00 2001
From: Mark Andrews <marka@isc.org>
Date: Mon, 21 Feb 2011 06:50:42 +0000
Subject: [PATCH] 3031.   [bug]           dns_rdataclass_format() handle a zero
 sized buffer.                         [RT #22521]

---
 CHANGES         |  3 +++
 lib/dns/rcode.c | 11 ++++++-----
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/CHANGES b/CHANGES
index e8455e47eb..dd831c7b43 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+3031.	[bug]		dns_rdataclass_format() handle a zero sized buffer.
+			[RT #22521]
+
 3030.	[bug]		dns_rdatatype_format() handle a zero sized buffer.
 			[RT #22521]
 
diff --git a/lib/dns/rcode.c b/lib/dns/rcode.c
index fd9d2fe0d3..d8c07cb589 100644
--- a/lib/dns/rcode.c
+++ b/lib/dns/rcode.c
@@ -15,7 +15,7 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: rcode.c,v 1.16 2010/12/23 04:07:58 marka Exp $ */
+/* $Id: rcode.c,v 1.17 2011/02/21 06:50:42 marka Exp $ */
 
 #include <config.h>
 #include <ctype.h>
@@ -494,6 +494,9 @@ dns_rdataclass_format(dns_rdataclass_t rdclass,
 	isc_result_t result;
 	isc_buffer_t buf;
 
+	if (size == 0U)
+		return;
+
 	isc_buffer_init(&buf, array, size);
 	result = dns_rdataclass_totext(rdclass, &buf);
 	/*
@@ -505,8 +508,6 @@ dns_rdataclass_format(dns_rdataclass_t rdclass,
 		else
 			result = ISC_R_NOSPACE;
 	}
-	if (result != ISC_R_SUCCESS) {
-		snprintf(array, size, "<unknown>");
-		array[size - 1] = '\0';
-	}
+	if (result != ISC_R_SUCCESS)
+		strlcpy(array, "<unknown>", size);
 }