"SHOW CHARACTER SET" now displays 1 for 8bit charsets in "mb_maxlen" column.

0 was dispayed before, this looked confusing.

sql/sql_show.cc

@@ -1391,7 +1391,7 @@ int mysqld_show_charsets(THD *thd, const char *wild)
       net_store_data(&packet2,convert,cs->name);
       net_store_data(&packet2,(uint32) cs->number);
       net_store_data(&packet2,(uint32) cs->strxfrm_multiply);
-      net_store_data(&packet2,(uint32) cs->mbmaxlen);
+      net_store_data(&packet2,(uint32) cs->mbmaxlen ? cs->mbmaxlen : 1);
 
       if (my_net_write(&thd->net, (char*) packet2.ptr(),packet2.length()))
          goto err;