From 9b08faf0bdaf5a4f2e6e3dd1ea7e8c57f70418d6 Mon Sep 17 00:00:00 2001
From: "Roger A. Light" <roger@atchoo.org>
Date: Tue, 9 Feb 2021 14:09:53 +0000
Subject: [PATCH] Fix mosquitto_{pub|sub}_topic_check() function returns.

The would not return MOSQ_ERR_INVAL on topic == NULL.
---
 ChangeLog.txt    |  5 +++++
 lib/util_topic.c | 19 ++++++++++++++++---
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/ChangeLog.txt b/ChangeLog.txt
index 214974b0..33457bbd 100644
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -8,10 +8,15 @@ Broker:
 - Give compile time warning if libwebsockets compiled without external poll
   support. Closes #2060.
 
+Client library:
+- Fix mosquitto_{pub|sub}_topic_check() functions not returning MOSQ_ERR_INVAL
+  on topic == NULL.
+
 Clients:
 - Fix possible loss of data in `mosquitto_pub -l` when sending multiple long
   lines. Closes #2078.
 
+
 2.0.7 - 2021-02-04
 ==================
 
diff --git a/lib/util_topic.c b/lib/util_topic.c
index fc24f0d1..62b53112 100644
--- a/lib/util_topic.c
+++ b/lib/util_topic.c
@@ -54,6 +54,11 @@ int mosquitto_pub_topic_check(const char *str)
 #ifdef WITH_BROKER
 	int hier_count = 0;
 #endif
+
+	if(str == NULL){
+		return MOSQ_ERR_INVAL;
+	}
+
 	while(str && str[0]){
 		if(str[0] == '+' || str[0] == '#'){
 			return MOSQ_ERR_INVAL;
@@ -81,7 +86,9 @@ int mosquitto_pub_topic_check2(const char *str, size_t len)
 	int hier_count = 0;
 #endif
 
-	if(len > 65535) return MOSQ_ERR_INVAL;
+	if(str == NULL || len > 65535){
+		return MOSQ_ERR_INVAL;
+	}
 
 	for(i=0; i<len; i++){
 		if(str[i] == '+' || str[i] == '#'){
@@ -115,7 +122,11 @@ int mosquitto_sub_topic_check(const char *str)
 	int hier_count = 0;
 #endif
 
-	while(str && str[0]){
+	if(str == NULL){
+		return MOSQ_ERR_INVAL;
+	}
+
+	while(str[0]){
 		if(str[0] == '+'){
 			if((c != '\0' && c != '/') || (str[1] != '\0' && str[1] != '/')){
 				return MOSQ_ERR_INVAL;
@@ -150,7 +161,9 @@ int mosquitto_sub_topic_check2(const char *str, size_t len)
 	int hier_count = 0;
 #endif
 
-	if(len > 65535) return MOSQ_ERR_INVAL;
+	if(str == NULL || len > 65535){
+		return MOSQ_ERR_INVAL;
+	}
 
 	for(i=0; i<len; i++){
 		if(str[i] == '+'){