From 49ebb585693aa3361b9ec235c1a2d28407a2091d Mon Sep 17 00:00:00 2001
From: "Roger A. Light" <roger@atchoo.org>
Date: Mon, 15 Aug 2022 22:17:00 +0100
Subject: [PATCH] Fix failure to close thread in some situations.

Closes #2545. Thanks to p-luke.
---
 ChangeLog.txt            |  1 +
 lib/connect.c            |  2 ++
 lib/loop.c               |  7 ++-----
 lib/mosquitto_internal.h |  1 +
 lib/util_mosq.c          | 20 ++++++++++++++++++++
 lib/util_mosq.h          |  4 ++++
 6 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/ChangeLog.txt b/ChangeLog.txt
index 5a165de1a3..79f2ee7789 100644
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -36,6 +36,7 @@ Client library:
 - Fix documentation omission around mosquitto_reinitialise. Closes #2489.
 - Fix use of MOSQ_OPT_SSL_CTX when used in conjunction with
   MOSQ_OPT_SSL_CTX_DEFAULTS. Closes #2463.
+- Fix failure to close thread in some situations. Closes #2545.
 
 Clients:
 - Fix mosquitto_pub incorrectly reusing topic aliases when reconnecting.
diff --git a/lib/connect.c b/lib/connect.c
index ab61b66c25..dfc57fa25f 100644
--- a/lib/connect.c
+++ b/lib/connect.c
@@ -76,6 +76,7 @@ static int mosquitto__connect_init(struct mosquitto *mosq, const char *host, int
 	mosq->msgs_in.inflight_quota = mosq->msgs_in.inflight_maximum;
 	mosq->msgs_out.inflight_quota = mosq->msgs_out.inflight_maximum;
 	mosq->retain_available = 1;
+	mosquitto__set_request_disconnect(mosq, false);
 
 	return MOSQ_ERR_SUCCESS;
 }
@@ -255,6 +256,7 @@ int mosquitto_disconnect_v5(struct mosquitto *mosq, int reason_code, const mosqu
 	}
 
 	mosquitto__set_state(mosq, mosq_cs_disconnected);
+	mosquitto__set_request_disconnect(mosq, true);
 	if(mosq->sock == INVALID_SOCKET){
 		return MOSQ_ERR_NO_CONN;
 	}else{
diff --git a/lib/loop.c b/lib/loop.c
index eb12854efc..965294f052 100644
--- a/lib/loop.c
+++ b/lib/loop.c
@@ -242,7 +242,6 @@ int mosquitto_loop_forever(struct mosquitto *mosq, int timeout, int max_packets)
 	int run = 1;
 	int rc = MOSQ_ERR_SUCCESS;
 	unsigned long reconnect_delay;
-	enum mosquitto_client_state state;
 
 	if(!mosq) return MOSQ_ERR_INVAL;
 
@@ -281,8 +280,7 @@ int mosquitto_loop_forever(struct mosquitto *mosq, int timeout, int max_packets)
 			pthread_testcancel();
 #endif
 			rc = MOSQ_ERR_SUCCESS;
-			state = mosquitto__get_state(mosq);
-			if(state == mosq_cs_disconnecting || state == mosq_cs_disconnected){
+			if(mosquitto__get_request_disconnect(mosq)){
 				run = 0;
 			}else{
 				if(mosq->reconnect_delay_max > mosq->reconnect_delay){
@@ -304,8 +302,7 @@ int mosquitto_loop_forever(struct mosquitto *mosq, int timeout, int max_packets)
 				rc = interruptible_sleep(mosq, (time_t)reconnect_delay);
 				if(rc) return rc;
 
-				state = mosquitto__get_state(mosq);
-				if(state == mosq_cs_disconnecting || state == mosq_cs_disconnected){
+				if(mosquitto__get_request_disconnect(mosq)){
 					run = 0;
 				}else{
 					rc = mosquitto_reconnect(mosq);
diff --git a/lib/mosquitto_internal.h b/lib/mosquitto_internal.h
index 87718ea9bf..ac71ffbf3e 100644
--- a/lib/mosquitto_internal.h
+++ b/lib/mosquitto_internal.h
@@ -339,6 +339,7 @@ struct mosquitto {
 	unsigned int reconnect_delay;
 	unsigned int reconnect_delay_max;
 	bool reconnect_exponential_backoff;
+	bool request_disconnect;
 	char threaded;
 	struct mosquitto__packet *out_packet_last;
 	mosquitto_property *connect_properties;
diff --git a/lib/util_mosq.c b/lib/util_mosq.c
index f4f868b963..22f8c4d5d5 100644
--- a/lib/util_mosq.c
+++ b/lib/util_mosq.c
@@ -302,3 +302,23 @@ enum mosquitto_client_state mosquitto__get_state(struct mosquitto *mosq)
 
 	return state;
 }
+
+#ifndef WITH_BROKER
+void mosquitto__set_request_disconnect(struct mosquitto *mosq, bool request_disconnect)
+{
+	pthread_mutex_lock(&mosq->state_mutex);
+	mosq->request_disconnect = request_disconnect;
+	pthread_mutex_unlock(&mosq->state_mutex);
+}
+
+bool mosquitto__get_request_disconnect(struct mosquitto *mosq)
+{
+	bool request_disconnect;
+
+	pthread_mutex_lock(&mosq->state_mutex);
+	request_disconnect = mosq->request_disconnect;
+	pthread_mutex_unlock(&mosq->state_mutex);
+
+	return request_disconnect;
+}
+#endif
diff --git a/lib/util_mosq.h b/lib/util_mosq.h
index 7d993442d3..ecc0120c60 100644
--- a/lib/util_mosq.h
+++ b/lib/util_mosq.h
@@ -32,6 +32,10 @@ uint16_t mosquitto__mid_generate(struct mosquitto *mosq);
 
 int mosquitto__set_state(struct mosquitto *mosq, enum mosquitto_client_state state);
 enum mosquitto_client_state mosquitto__get_state(struct mosquitto *mosq);
+#ifndef WITH_BROKER
+void mosquitto__set_request_disconnect(struct mosquitto *mosq, bool request_disconnect);
+bool mosquitto__get_request_disconnect(struct mosquitto *mosq);
+#endif
 
 #ifdef WITH_TLS
 int mosquitto__hex2bin_sha1(const char *hex, unsigned char **bin);