Bug#25262 Auto Increment lost when changing Engine type

- Try to copy the autoincrement value when altering the table

mysql-test/r/alter_table.result

@@ -826,3 +826,27 @@ create table t1 (t varchar(255) default null, key t (t(80)))
 engine=myisam default charset=latin1;
 alter table t1 change t t text;
 drop table t1;
+create table t1(id int(8) primary key auto_increment) engine=heap;
+insert into t1 values (null);
+insert into t1 values (null);
+select * from t1;
+id
+1
+2
+alter table t1 auto_increment = 50;
+alter table t1 engine = myisam;
+insert into t1 values (null);
+select * from t1;
+id
+1
+2
+50
+alter table t1 engine = heap;
+insert into t1 values (null);
+select * from t1;
+id
+1
+2
+50
+51
+drop table t1;

mysql-test/r/bdb_notembedded.result

@@ -0,0 +1,35 @@
+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/alter_table.test

@@ -613,3 +613,31 @@ create table t1 (t varchar(255) default null, key t (t(80)))
 engine=myisam default charset=latin1;
 alter table t1 change t t text;
 drop table t1;
+
+#
+# Bug#25262 Auto Increment lost when changing Engine type
+#
+
+create table t1(id int(8) primary key auto_increment) engine=heap;
+
+insert into t1 values (null);
+insert into t1 values (null);
+
+select * from t1;
+
+# Set auto increment to 50
+alter table t1 auto_increment = 50;
+
+# Alter to myisam
+alter table t1 engine = myisam;
+
+# This insert should get id 50
+insert into t1 values (null);
+select * from t1;
+
+# Alter to heap again
+alter table t1 engine = heap;
+insert into t1 values (null);
+select * from t1;
+
+drop table t1;

mysql-test/t/bdb_notembedded.test

@@ -0,0 +1,38 @@
+-- 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/sql_table.cc

@@ -3274,6 +3274,12 @@ view_err:
     create_info->avg_row_length= table->s->avg_row_length;
   if (!(used_fields & HA_CREATE_USED_DEFAULT_CHARSET))
     create_info->default_table_charset= table->s->table_charset;
+  if (!(used_fields & HA_CREATE_USED_AUTO) && table->found_next_number_field)
+  {
+    /* Table has an autoincrement, copy value to new table */
+    table->file->info(HA_STATUS_AUTO);
+    create_info->auto_increment_value= table->file->auto_increment_value;
+  }
 
   restore_record(table, s->default_values);     // Empty record for DEFAULT
   List_iterator<Alter_drop> drop_it(alter_info->drop_list);