Fix for bug #7100: relay_log_space_max missing from SHOW VARIABLES

mysql-test/r/rpl000005.result

@@ -4,6 +4,9 @@ reset master;
 reset slave;
 drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
 start slave;
+SHOW VARIABLES LIKE 'relay_log_space_limit';
+Variable_name	Value
+relay_log_space_limit	0
 CREATE TABLE t1 (name varchar(64), age smallint(3));
 INSERT INTO  t1 SET name='Andy', age=31;
 INSERT t1 SET name='Jacob', age=2;

mysql-test/t/rpl000005.test

 source include/master-slave.inc;
 
+#
+# Bug#7100 relay_log_space_max missing from SHOW VARIABLES
+#
+SHOW VARIABLES LIKE 'relay_log_space_limit';
+
 CREATE TABLE t1 (name varchar(64), age smallint(3));
 INSERT INTO  t1 SET name='Andy', age=31;
 INSERT t1 SET name='Jacob', age=2;

sql/set_var.cc

@@ -845,6 +845,7 @@ struct show_var_st init_vars[]= {
   {sys_read_rnd_buff_size.name,(char*) &sys_read_rnd_buff_size,	    SHOW_SYS},
 #ifdef HAVE_REPLICATION
   {sys_relay_log_purge.name,  (char*) &sys_relay_log_purge,         SHOW_SYS},
+  {"relay_log_space_limit",  (char*) &relay_log_space_limit,        SHOW_LONGLONG},
 #endif
   {sys_rpl_recovery_rank.name,(char*) &sys_rpl_recovery_rank,       SHOW_SYS},
   {"secure_auth",             (char*) &sys_secure_auth,             SHOW_SYS},