set_var.cc:

  Whack duplicate variable line. (Affects SHOW VARIABLES.)

sql/set_var.cc

@@ -724,7 +724,6 @@ struct show_var_st init_vars[]= {
   {"innodb_log_group_home_dir", (char*) &innobase_log_group_home_dir, SHOW_CHAR_PTR},
   {sys_innodb_max_dirty_pages_pct.name, (char*) &sys_innodb_max_dirty_pages_pct, SHOW_SYS},
   {sys_innodb_max_purge_lag.name, (char*) &sys_innodb_max_purge_lag, SHOW_SYS},
-  {sys_innodb_max_purge_lag.name, (char*) &sys_innodb_max_purge_lag, SHOW_SYS},
   {"innodb_mirrored_log_groups", (char*) &innobase_mirrored_log_groups, SHOW_LONG},
   {"innodb_open_files", (char*) &innobase_open_files, SHOW_LONG },
   {sys_innodb_table_locks.name, (char*) &sys_innodb_table_locks, SHOW_SYS},