BUG#26675 Add ndb_connectstring in "show global variables".

sql/ha_ndbcluster.h:
  Extern opt_ndb_constrbuf array from mysqld
sql/set_var.cc:
  Add ndb_connectstring to sys variable

mysql-test/r/bdb_notembedded.result

+set autocommit=1;
+reset master;
+create table bug16206 (a int);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+show binlog events;
+Log_name	Pos	Event_type	Server_id	End_log_pos	Info
+f	n	Format_desc	1	n	Server ver: VERSION, Binlog ver: 4
+f	n	Query	1	n	use `test`; create table bug16206 (a int)
+f	n	Query	1	n	use `test`; insert into bug16206 values(1)
+f	n	Query	1	n	use `test`; insert into bug16206 values(2)
+drop table bug16206;
+reset master;
+create table bug16206 (a int) engine=         bdb;
+insert into bug16206 values(0);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+insert into bug16206 values(3);
+show binlog events;
+Log_name	Pos	Event_type	Server_id	End_log_pos	Info
+f	n	Format_desc	1	n	Server ver: VERSION, Binlog ver: 4
+f	n	Query	1	n	use `test`; create table bug16206 (a int) engine=         bdb
+f	n	Query	1	n	use `test`; insert into bug16206 values(0)
+f	n	Query	1	n	use `test`; insert into bug16206 values(1)
+f	n	Query	1	n	use `test`; BEGIN
+f	n	Query	1	n	use `test`; insert into bug16206 values(2)
+f	n	Query	1	n	use `test`; COMMIT
+f	n	Query	1	n	use `test`; insert into bug16206 values(3)
+drop table bug16206;
+set autocommit=0;
+End of 5.0 tests

mysql-test/t/bdb_notembedded.test

+-- source include/not_embedded.inc
+-- source include/have_bdb.inc
+
+#
+# Bug #16206: Superfluous COMMIT event in binlog when updating BDB in autocommit mode
+#
+set autocommit=1;
+
+let $VERSION=`select version()`;
+
+reset master;
+create table bug16206 (a int);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+--replace_result $VERSION VERSION
+--replace_column 1 f 2 n 5 n
+show binlog events;
+drop table bug16206;
+
+reset master;
+create table bug16206 (a int) engine=         bdb;
+insert into bug16206 values(0);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+insert into bug16206 values(3);
+--replace_result $VERSION VERSION
+--replace_column 1 f 2 n 5 n
+show binlog events;
+drop table bug16206;
+
+set autocommit=0;
+
+
+--echo End of 5.0 tests

sql/ha_ndbcluster.h

@@ -40,6 +40,7 @@ class NdbBlob;
 // connectstring to cluster if given by mysqld
 extern const char *ndbcluster_connectstring;
 extern ulong ndb_cache_check_time;
+extern char opt_ndb_constrbuf[];
 
 typedef enum ndb_index_type {
   UNDEFINED_INDEX = 0,

sql/set_var.cc

@@ -476,6 +476,8 @@ sys_var_thd_bool
 sys_ndb_use_transactions("ndb_use_transactions", &SV::ndb_use_transactions);
 sys_var_long_ptr
 sys_ndb_cache_check_time("ndb_cache_check_time", &ndb_cache_check_time);
+sys_var_const_str
+sys_ndb_connectstring("ndb_connectstring", opt_ndb_constrbuf);
 #endif
 
 /* Time/date/datetime formats */
@@ -787,6 +789,7 @@ sys_var *sys_variables[]=
 #ifdef HAVE_NDBCLUSTER_DB
   &sys_ndb_autoincrement_prefetch_sz,
   &sys_ndb_cache_check_time,
+  &sys_ndb_connectstring,
   &sys_ndb_force_send,
   &sys_ndb_use_exact_count,
   &sys_ndb_use_transactions,
@@ -988,6 +991,7 @@ struct show_var_st init_vars[]= {
   {sys_ndb_use_exact_count.name,(char*) &sys_ndb_use_exact_count,   SHOW_SYS},
   {sys_ndb_use_transactions.name,(char*) &sys_ndb_use_transactions, SHOW_SYS},
   {sys_ndb_cache_check_time.name,(char*) &sys_ndb_cache_check_time, SHOW_SYS},
+  {sys_ndb_connectstring.name,(char*) &sys_ndb_connectstring,       SHOW_SYS},
 #endif
   {sys_net_buffer_length.name,(char*) &sys_net_buffer_length,       SHOW_SYS},
   {sys_net_read_timeout.name, (char*) &sys_net_read_timeout,        SHOW_SYS},