From 94d23360708d5c96b81e3c10fbf29b4c289f7462 Mon Sep 17 00:00:00 2001
From: Greg Hazel <ghazel@gmail.com>
Date: Wed, 18 Apr 2012 21:29:21 -0700
Subject: [PATCH 1/2] cancel the probe request when the server is freed, and
 ignore cancelled probe callbacks

---
 evdns.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/evdns.c b/evdns.c
index 02f5dff5..ba010d46 100644
--- a/evdns.c
+++ b/evdns.c
@@ -2250,6 +2250,10 @@ nameserver_probe_callback(int result, char type, int count, int ttl, void *addre
 	(void) ttl;
 	(void) addresses;
 
+	if (result == DNS_ERR_CANCEL) {
+		return;
+	}
+
 	EVDNS_LOCK(ns->base);
 	ns->probe_request = NULL;
 	if (result == DNS_ERR_CANCEL) {
@@ -2361,6 +2365,10 @@ evdns_base_clear_nameservers_and_suspend(struct evdns_base *base)
 		(void) event_del(&server->event);
 		if (evtimer_initialized(&server->timeout_event))
 			(void) evtimer_del(&server->timeout_event);
+		if (server->probe_request) {
+			evdns_cancel_request(server->base, server->probe_request);
+			server->probe_request = NULL;
+		}
 		if (server->socket >= 0)
 			evutil_closesocket(server->socket);
 		mm_free(server);

From 46b806084e5426982fbf94cb8f4cf1a95ded6c54 Mon Sep 17 00:00:00 2001
From: Greg Hazel <ghazel@gmail.com>
Date: Wed, 18 Apr 2012 21:41:48 -0700
Subject: [PATCH 2/2] remove redundant DNS_ERR_CANCEL check, move comment

---
 evdns.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/evdns.c b/evdns.c
index ba010d46..5db46248 100644
--- a/evdns.c
+++ b/evdns.c
@@ -2251,16 +2251,15 @@ nameserver_probe_callback(int result, char type, int count, int ttl, void *addre
 	(void) addresses;
 
 	if (result == DNS_ERR_CANCEL) {
+		/* We canceled this request because the nameserver came up
+		 * for some other reason.  Do not change our opinion about
+		 * the nameserver. */
 		return;
 	}
 
 	EVDNS_LOCK(ns->base);
 	ns->probe_request = NULL;
-	if (result == DNS_ERR_CANCEL) {
-		/* We canceled this request because the nameserver came up
-		 * for some other reason.  Do not change our opinion about
-		 * the nameserver. */
-	} else if (result == DNS_ERR_NONE || result == DNS_ERR_NOTEXIST) {
+	if (result == DNS_ERR_NONE || result == DNS_ERR_NOTEXIST) {
 		/* this is a good reply */
 		nameserver_up(ns);
 	} else {