v5 report reason code=no sub when unsubscribing.

src/handle_unsubscribe.c

@@ -31,6 +31,7 @@ int handle__unsubscribe(struct mosquitto_db *db, struct mosquitto *context)
 	char *sub;
 	int slen;
 	int rc;
+	uint8_t reason;
 	int reason_code_count = 0;
 	int reason_code_max;
 	uint8_t *reason_codes = NULL, *reason_tmp;
@@ -89,11 +90,12 @@ int handle__unsubscribe(struct mosquitto_db *db, struct mosquitto *context)
 		}
 
 		log__printf(NULL, MOSQ_LOG_DEBUG, "\t%s", sub);
-		sub__remove(db, context, sub, db->subs);
+		rc = sub__remove(db, context, sub, db->subs, &reason);
 		log__printf(NULL, MOSQ_LOG_UNSUBSCRIBE, "%s %s", context->id, sub);
 		mosquitto__free(sub);
+		if(rc) return rc;
 
-		reason_codes[reason_code_count] = 0;
+		reason_codes[reason_code_count] = reason;
 		reason_code_count++;
 		if(reason_code_count == reason_code_max){
 			reason_tmp = mosquitto__realloc(reason_codes, reason_code_max*2);

src/mosquitto_broker_internal.h

@@ -584,7 +584,7 @@ void sys_tree__update(struct mosquitto_db *db, int interval, time_t start_time);
  * ============================================================ */
 int sub__add(struct mosquitto_db *db, struct mosquitto *context, const char *sub, int qos, uint32_t identifier, int options, struct mosquitto__subhier **root);
 struct mosquitto__subhier *sub__add_hier_entry(struct mosquitto__subhier *parent, struct mosquitto__subhier **sibling, const char *topic, size_t len);
-int sub__remove(struct mosquitto_db *db, struct mosquitto *context, const char *sub, struct mosquitto__subhier *root);
+int sub__remove(struct mosquitto_db *db, struct mosquitto *context, const char *sub, struct mosquitto__subhier *root, uint8_t *reason);
 void sub__tree_print(struct mosquitto__subhier *root, int level);
 int sub__clean_session(struct mosquitto_db *db, struct mosquitto *context);
 int sub__retain_queue(struct mosquitto_db *db, struct mosquitto *context, const char *sub, int sub_qos, uint32_t subscription_identifier);

src/subs.c

@@ -324,7 +324,7 @@ static int sub__add_recurse(struct mosquitto_db *db, struct mosquitto *context,
 	}
 }
 
-static int sub__remove_recurse(struct mosquitto_db *db, struct mosquitto *context, struct mosquitto__subhier *subhier, struct sub__token *tokens)
+static int sub__remove_recurse(struct mosquitto_db *db, struct mosquitto *context, struct mosquitto__subhier *subhier, struct sub__token *tokens, uint8_t *reason)
 {
 	struct mosquitto__subhier *branch;
 	struct mosquitto__subleaf *leaf;
@@ -357,6 +357,7 @@ static int sub__remove_recurse(struct mosquitto_db *db, struct mosquitto *contex
 						break;
 					}
 				}
+				*reason = 0;
 				return MOSQ_ERR_SUCCESS;
 			}
 			leaf = leaf->next;
@@ -366,7 +367,7 @@ static int sub__remove_recurse(struct mosquitto_db *db, struct mosquitto *contex
 
 	HASH_FIND(hh, subhier->children, UHPA_ACCESS_TOPIC(tokens), tokens->topic_len, branch);
 	if(branch){
-		sub__remove_recurse(db, context, branch, tokens->next);
+		sub__remove_recurse(db, context, branch, tokens->next, reason);
 		if(!branch->children && !branch->subs && !branch->retained){
 			HASH_DELETE(hh, subhier->children, branch);
 			UHPA_FREE_TOPIC(branch);
@@ -478,7 +479,7 @@ int sub__add(struct mosquitto_db *db, struct mosquitto *context, const char *sub
 	return rc;
 }
 
-int sub__remove(struct mosquitto_db *db, struct mosquitto *context, const char *sub, struct mosquitto__subhier *root)
+int sub__remove(struct mosquitto_db *db, struct mosquitto *context, const char *sub, struct mosquitto__subhier *root, uint8_t *reason)
 {
 	int rc = 0;
 	struct mosquitto__subhier *subhier;
@@ -491,7 +492,8 @@ int sub__remove(struct mosquitto_db *db, struct mosquitto *context, const char *
 
 	HASH_FIND(hh, root, UHPA_ACCESS_TOPIC(tokens), tokens->topic_len, subhier);
 	if(subhier){
-		rc = sub__remove_recurse(db, context, subhier, tokens);
+		*reason = MQTT_RC_NO_SUBSCRIPTION_EXISTED;
+		rc = sub__remove_recurse(db, context, subhier, tokens, reason);
 	}
 
 	sub__topic_tokens_free(tokens);

test/broker/02-unsubscribe-qos2-multiple-v5.py

@@ -1,23 +1,29 @@
 #!/usr/bin/env python
 
-# Test whether a v5 UNSUBSCRIBE to multiple topics with QoS 2 results in the correct UNSUBACK packet.
+# Test whether a v5 UNSUBSCRIBE to multiple topics with QoS 2 results in the
+# correct UNSUBACK packet, when one subscription exists and the other does not.
 
 from mosq_test_helper import *
 
 rc = 1
-mid = 3
 keepalive = 60
 connect_packet = mosq_test.gen_connect("unsubscribe-qos2-test", keepalive=keepalive, proto_ver=5)
 connack_packet = mosq_test.gen_connack(rc=0, proto_ver=5)
 
+mid = 1
+subscribe_packet = mosq_test.gen_subscribe(mid, "qos2/two", 2, proto_ver=5)
+suback_packet = mosq_test.gen_suback(mid, 2, proto_ver=5)
+
+mid = 3
 unsubscribe_packet = mosq_test.gen_unsubscribe_multiple(mid, ["qos2/one", "qos2/two"], proto_ver=5)
-unsuback_packet = mosq_test.gen_unsuback(mid, proto_ver=5, reason_code=[0, 0])
+unsuback_packet = mosq_test.gen_unsuback(mid, proto_ver=5, reason_code=[17, 0])
 
 port = mosq_test.get_port()
 broker = mosq_test.start_broker(filename=os.path.basename(__file__), port=port)
 
 try:
     sock = mosq_test.do_client_connect(connect_packet, connack_packet, port=port)
+    mosq_test.do_send_receive(sock, subscribe_packet, suback_packet, "suback")
     mosq_test.do_send_receive(sock, unsubscribe_packet, unsuback_packet, "unsuback")
 
     rc = 0

test/broker/02-unsubscribe-qos2-v5.py

@@ -12,7 +12,7 @@ connect_packet = mosq_test.gen_connect("unsubscribe-qos2-test", keepalive=keepal
 connack_packet = mosq_test.gen_connack(rc=0, proto_ver=5)
 
 unsubscribe_packet = mosq_test.gen_unsubscribe(mid, "qos2/test", proto_ver=5)
-unsuback_packet = mosq_test.gen_unsuback(mid, proto_ver=5)
+unsuback_packet = mosq_test.gen_unsuback(mid, proto_ver=5, reason_code=17)
 
 port = mosq_test.get_port()
 broker = mosq_test.start_broker(filename=os.path.basename(__file__), port=port)