BUG#6676: Derivation of user variables should be of derivation "IMPLICIT"

mysql-test/r/rpl_charset.result

@@ -207,3 +207,10 @@ select hex(c1), hex(c2) from t1;
 hex(c1)	hex(c2)
 CDF32C20E7E020F0FBE1E0EBEAF3	CDF32C20E7E020F0FBE1E0EBEAF3
 drop table t1;
+create table `t1` (
+`pk` varchar(10) not null default '', 
+primary key (`pk`)
+) engine=myisam default charset=latin1;
+set @p=_latin1 'test';
+update t1 set pk='test' where pk=@p;
+drop table t1;

mysql-test/t/rpl_charset.test

@@ -169,3 +169,16 @@ select hex(c1), hex(c2) from t1;
 connection master;
 drop table t1;
 sync_slave_with_master;
+
+#
+#  BUG#6676: Derivation of variables must be correct on slave
+#
+connection master;
+create table `t1` (
+  `pk` varchar(10) not null default '', 
+  primary key (`pk`)
+) engine=myisam default charset=latin1;
+set @p=_latin1 'test';
+update t1 set pk='test' where pk=@p;
+drop table t1;
+sync_slave_with_master;

sql/log_event.cc

@@ -2528,7 +2528,7 @@ int User_var_log_event::exec_event(struct st_relay_log_info* rli)
     0 can be passed as last argument (reference on item)
   */
   e.fix_fields(thd, 0, 0);
-  e.update_hash(val, val_len, type, charset, DERIVATION_NONE);
+  e.update_hash(val, val_len, type, charset, DERIVATION_IMPLICIT);
   free_root(thd->mem_root,0);
 
   rli->inc_event_relay_log_pos(get_event_len());