[425835] Support for "hour client expiration times.

This allows shorter values for the persistent_client_expiration option.

Bug: https://bugs.eclipse.org/bugs/show_bug.cgi?id=425835

ChangeLog.txt

@@ -53,6 +53,8 @@ Broker:
   of UNSUBSCRIBE requests to be disabled for topics with "out" direction.
   Closes bug #456899.
 - Wildcard TLS certificates are now supported for bridges.
+- Support for "hour" client expiration lengths for the
+  persistent_client_expiration option. Closes bug #425835.
 
 Clients:
 - Both clients can now load default configuration options from a file.

man/mosquitto.conf.5.xml

@@ -454,7 +454,7 @@
 						to persistent clients that will never reconnect. This
 						option allows these clients to be removed.</para>
 					<para>The expiration period should be an integer followed
-						by one of d w m y for day, week, month and year
+						by one of h d w m y for hour, day, week, month and year
 						respectively. For example:</para>
 					<itemizedlist mark="circle">
 						<listitem><para>persistent_client_expiration 2m</para></listitem>

mosquitto.conf

@@ -91,8 +91,8 @@
 # generated client id. This leads to persistent clients that will never
 # reconnect. This option allows these clients to be removed.
 #
-# The expiration period should be an integer followed by one of d w m y for
-# day, week, month and year respectively. For example
+# The expiration period should be an integer followed by one of h d w m y for
+# hour, day, week, month and year respectively. For example
 #
 # persistent_client_expiration 2m
 # persistent_client_expiration 14d

src/conf.c

@@ -1479,6 +1479,9 @@ int _config_read_file_core(struct mqtt3_config *config, bool reload, const char
 					token = strtok_r(NULL, " ", &saveptr);
 					if(token){
 						switch(token[strlen(token)-1]){
+							case 'h':
+								expiration_mult = 3600;
+								break;
 							case 'd':
 								expiration_mult = 86400;
 								break;