Fix description of `-e` and `-t` arguments in mosquitto_rr.

Closes #1881. Thanks to Arnav Singh.

ChangeLog.txt

@@ -128,6 +128,7 @@ Clients:
 - mosquitto_sub now supports extra format specifiers for field width and
   precision for some parameters.
 - Add `--version` for all clients.
+- Fix description of `-e` and `-t` arguments in mosquitto_rr. Closes #1881.
 
 
 1.6.12 - 2020-08-19

client/rr_client.c

@@ -70,7 +70,11 @@ void my_signal_handler(int signum)
 
 int my_publish(struct mosquitto *mosq, int *mid, const char *topic, int payloadlen, void *payload, int qos, bool retain)
 {
-	return mosquitto_publish_v5(mosq, mid, topic, payloadlen, payload, qos, retain, cfg.publish_props);
+	if(cfg.protocol_version < MQTT_PROTOCOL_V5){
+		return mosquitto_publish_v5(mosq, mid, topic, payloadlen, payload, qos, retain, NULL);
+	}else{
+		return mosquitto_publish_v5(mosq, mid, topic, payloadlen, payload, qos, retain, cfg.publish_props);
+	}
 }
 
 
@@ -209,6 +213,7 @@ void print_usage(void)
 	printf("      argument.\n");
 	printf(" -d : enable debug messages.\n");
 	printf(" -D : Define MQTT v5 properties. See the documentation for more details.\n");
+	printf(" -e : Response topic. The client will subscribe to this topic to wait for a response.\n");
 	printf(" -F : output format.\n");
 	printf(" -h : mqtt host to connect to. Defaults to localhost.\n");
 	printf(" -i : id to use for this client. Defaults to mosquitto_rr_ appended with the process id.\n");
@@ -223,7 +228,7 @@ void print_usage(void)
 #ifdef WITH_SRV
 	printf(" -S : use SRV lookups to determine which host to connect to.\n");
 #endif
-	printf(" -t : mqtt response topic to subscribe to. May be repeated multiple times.\n");
+	printf(" -t : topic where the request message will be sent.\n");
 	printf(" -u : provide a username\n");
 	printf(" -v : print received messages verbosely.\n");
 	printf(" -V : specify the version of the MQTT protocol to use when connecting.\n");

man/mosquitto_rr.1.xml

@@ -17,6 +17,7 @@
 	<refsynopsisdiv>
 		<cmdsynopsis>
 			<command>mosquitto_rr</command>
+			<arg choice='plain'><option>-e</option> <replaceable>response-topic</replaceable></arg>
 			<group choice='req'>
 				<arg choice='plain'>
 					<arg><option>-h</option> <replaceable>hostname</replaceable></arg>
@@ -30,7 +31,6 @@
 					<arg choice='plain'><option>-L</option> <replaceable>URL</replaceable></arg>
 					<arg choice='opt' rep='repeat'><option>-t</option> <replaceable>message-topic</replaceable></arg>
 				</arg>
-				<arg><option>-e</option> <replaceable>response-topic</replaceable></arg>
 			</group>
 			<group choice='req'>
 				<arg choice='plain'><option>-f</option> <replaceable>file</replaceable></arg>
@@ -106,6 +106,10 @@
 			response. When using MQTT v5, which is the default,
 			<command>mosquitto_rr</command> will use the Request-Response
 			feature.</para>
+		<para>The important options are <option>-t</option>, <option>-e</option>,
+			and one of <option>-f</option>, <option>-m</option>, <option>-n</option>,
+			and <option>-s</option>.</para>
+		<para>Example: <code>mosquitto_rr -t request-topic -e response-topic -m message</code></para>
 	</refsect1>
 
 	<refsect1>
@@ -246,6 +250,12 @@
 						the pair.</para>
 				</listitem>
 			</varlistentry>
+			<varlistentry>
+				<term><option>-e</option></term>
+				<listitem>
+					<para>Response topic. The client will subscribe to this topic to wait for a response.</para>
+				</listitem>
+			</varlistentry>
 			<varlistentry>
 				<term><option>-f</option></term>
 				<term><option>--file</option></term>
@@ -521,11 +531,7 @@
 				<term><option>-t</option></term>
 				<term><option>--topic</option></term>
 				<listitem>
-					<para>The MQTT topic to subscribe to, where responses will
-						be waited for. See
-					<citerefentry><refentrytitle>mqtt</refentrytitle><manvolnum>7</manvolnum></citerefentry>
-					for more information on MQTT topics.</para>
-					<para>This option may be repeated to subscribe to multiple topics.</para>
+					<para>The MQTT topic where the request message will be sent.</para>
 				</listitem>
 			</varlistentry>
 			<varlistentry>