bind/bind-9.18-fix-dig-hanging-issue.patch

diff --git a/bin/dig/dighost.c b/bin/dig/dighost.c
index 7e88b6b63c..768c4e56da 100644
--- a/bin/dig/dighost.c
+++ b/bin/dig/dighost.c
@@ -1577,6 +1577,31 @@ check_if_done(void) {
 	}
 }
 
+
+/*%
+ * Check if we're done with all the queries in the lookup, except for
+ * the `except_q` query (can be NULL if no exception is required).
+ * Expects `l` to be a valid and locked lookup.
+ */
+static bool
+check_if_queries_done(dig_lookup_t *l, dig_query_t *except_q) {
+	dig_query_t *q = ISC_LIST_HEAD(l->q);
+
+	debug("check_if_queries_done(%p)", l);
+
+	while (q != NULL) {
+		if (!q->started || q->waiting_connect || q->waiting_senddone || q->pending_free) {
+			if (!q->canceled && q != except_q) {
+				debug("there is a pending query %p", q);
+				return (false);
+			}
+		}
+		q = ISC_LIST_NEXT(q, link);
+	}
+
+	return (true);
+}
+
 /*%
  * Clear out a query when we're done with it.  WARNING: This routine
  * WILL invalidate the query pointer.
@@ -2563,7 +2588,6 @@ setup_lookup(dig_lookup_t *lookup) {
 		query->waiting_senddone = false;
 		query->pending_free = false;
 		query->recv_made = false;
-		query->first_pass = true;
 		query->first_soa_rcvd = false;
 		query->second_rr_rcvd = false;
 		query->first_repeat_rcvd = false;
@@ -2663,6 +2687,7 @@ cancel_lookup(dig_lookup_t *lookup) {
 	while (query != NULL) {
 		REQUIRE(DIG_VALID_QUERY(query));
 		next = ISC_LIST_NEXT(query, link);
+		query->canceled = true;
 		if (query->sock != NULL) {
 			isc_socket_cancel(query->sock, global_task,
 					  ISC_SOCKCANCEL_ALL);
@@ -2905,6 +2930,12 @@ send_udp(dig_query_t *query) {
 			return;
 		}
 
+		query->started = true;
+		if (atomic_load(&cancel_now)) {
+			return;
+		}
+		INSIST(!free_now);
+
 		result = isc_socket_create(socketmgr,
 					   isc_sockaddr_pf(&query->sockaddr),
 					   isc_sockettype_udp, &query->sock);
@@ -3031,6 +3062,10 @@ connect_timeout(isc_task_t *task, isc_event_t *event) {
 				clear_query(query);
 			}
 		}
+		if (check_if_queries_done(l, query)) {
+			cancel_lookup(l);
+			check_next_lookup(l);
+		}
 		UNLOCK_LOOKUP;
 		return;
 	}
@@ -3286,6 +3321,14 @@ connect_done(isc_task_t *task, isc_event_t *event) {
 	query = sevent->ev_arg;
 	REQUIRE(DIG_VALID_QUERY(query));
 
+	query->started = true;
+
+	if (atomic_load(&cancel_now)) {
+		return;
+	}
+
+	INSIST(!free_now);
+
 	INSIST(query->waiting_connect);
 
 	query->waiting_connect = false;
@@ -4002,6 +4045,9 @@ recv_done(isc_task_t *task, isc_event_t *event) {
 						 : "recursion not available",
 					 query->servname);
 			clear_query(query);
+			if (check_if_queries_done(l, query)) {
+				cancel_lookup(l);
+			}
 			check_next_lookup(l);
 			dns_message_detach(&msg);
 			isc_event_free(&event);
@@ -4126,7 +4172,12 @@ recv_done(isc_task_t *task, isc_event_t *event) {
 				l->trace_root = false;
 				usesearch = false;
 			} else {
+				/*
+				 * This is a query in the followup lookup
+				 */
 				dighost_printmessage(query, &b, msg, true);
+
+				docancel = check_if_queries_done(l, query);
 			}
 		}
 	}
@@ -4305,6 +4356,7 @@ cancel_all(void) {
 			nq = ISC_LIST_NEXT(q, link);
 			debug("canceling pending query %p, belonging to %p", q,
 			      current_lookup);
+			q->canceled = true;
 			if (q->sock != NULL) {
 				isc_socket_cancel(q->sock, NULL,
 						  ISC_SOCKCANCEL_ALL);
@@ -4317,6 +4369,7 @@ cancel_all(void) {
 			nq = ISC_LIST_NEXT(q, clink);
 			debug("canceling connecting query %p, belonging to %p",
 			      q, current_lookup);
+			q->canceled = true;
 			if (q->sock != NULL) {
 				isc_socket_cancel(q->sock, NULL,
 						  ISC_SOCKCANCEL_ALL);
diff --git a/bin/dig/include/dig/dig.h b/bin/dig/include/dig/dig.h
index 9e6035255f..48c6262008 100644
--- a/bin/dig/include/dig/dig.h
+++ b/bin/dig/include/dig/dig.h
@@ -166,9 +166,9 @@ struct dig_lookup {
 struct dig_query {
 	unsigned int  magic;
 	dig_lookup_t *lookup;
-	bool waiting_connect, pending_free, waiting_senddone, first_pass,
+	bool waiting_connect, pending_free, waiting_senddone, started,
 		first_soa_rcvd, second_rr_rcvd, first_repeat_rcvd, recv_made,
-		warn_id, timedout;
+		warn_id, timedout, canceled;
 	uint32_t      first_rr_serial;
 	uint32_t      second_rr_serial;
 	uint32_t      msg_count;
diff --git a/bin/tests/system/digdelv/tests.sh b/bin/tests/system/digdelv/tests.sh
index 22933c7f9d..4b0ed7db10 100644
--- a/bin/tests/system/digdelv/tests.sh
+++ b/bin/tests/system/digdelv/tests.sh
@@ -1043,6 +1043,15 @@ if [ -x "$DIG" ] ; then
   if [ $ret -ne 0 ]; then echo_i "failed"; fi
   status=$((status+ret))
 
+  # See [GL #3248] for more information
+  n=$((n+1))
+  echo_i "check that dig correctly refuses to use a server with a IPv4 mapped IPv6 address after failing with a regular IP address ($n)"
+  ret=0
+  dig_with_opts +nomapped @10.53.0.8 @::ffff:10.53.0.8 a.example > dig.out.test$n 2>&1 || ret=1
+  grep -F ";; Skipping mapped address" dig.out.test$n > /dev/null || ret=1
+  grep -F ";; No acceptable nameservers" dig.out.test$n > /dev/null || ret=1
+  if [ $ret -ne 0 ]; then echo_i "failed"; fi
+  status=$((status+ret))
 else
   echo_i "$DIG is needed, so skipping these dig tests"
 fi