Fix reloading of listeners where multiple listeners have the same port.

This is only possible where they have different bind addresses.

Closes #2029. Thanks to Simon Aldrich.

ChangeLog.txt

@@ -7,6 +7,8 @@ Broker:
 - Add notes that libsystemd-dev or similar is needed if building with systemd
  support. Closes #2019.
 - Improve logging in obscure cases when a client disconnects. Closes #2017.
+- Fix reloading of listeners where multiple listeners have been defined with
+ the same port but different bind addresses. Closes #2029.
 
 Apps:
 - Allow command line arguments to override config file options in

src/conf.c

@@ -1417,8 +1417,21 @@ int config__read_file_core(struct mosquitto__config *config, bool reload, struct
  {
  for(i=0; i<config->listener_count; i++){
  if(config->listeners[i].port == tmp_int){
- cur_listener = &config->listeners[i];
- break;
+ /* Now check we have a matching bind address, if defined */
+ if(config->listeners[i].host){
+ if(token && !strcmp(config->listeners[i].host, token)){
+ /* They both have a bind address, and they match */
+ cur_listener = &config->listeners[i];
+ break;
+ }
+ }else{
+ if(token == NULL){
+ /* Neither this config nor the new config have a bind address,
+ * so they match. */
+ cur_listener = &config->listeners[i];
+ break;
+ }
+ }
  }
  }
  }